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Harm H. Kampinga
Dept. of Cell Biology, UMC Groningen, The Netherlands
Cell Stress and Chaperones:basic concepts
Cell Stress and Chaperones: basic concepts -‐ Harm H. Kampinga
1
Ritossa, 1962
Tissieres et al ., 1974
Cell Stress and Chaperones: basic concepts -‐ Harm H. Kampinga
Originally, heat shock genes (Ritossa, 1962) and later heat shock proteins (Tissieres et al 1974), were described to be genes/proteins of which the expression increased aBer an heat shock.
2
Originally, heat shock genes (Ritossa, 1962) and later heat shock proteins (Tissieres et al 1974), were described to be genes/proteins of which the expression increased aBer an heat shock. Heat shock proteins (HSP) were defined as proteins encoded by genes that contain so-‐called “heat shock elements (HSE) in their genes that are regulated by the “heat shock transcripNon factor-‐1 (HSF-‐1)”
Cell Stress and Chaperones: basic concepts -‐ Harm H. Kampinga
3
Akerfelt et al., 2011
Originally, heat shock genes (Ritossa, 1962) and later heat shock proteins (Tissieres et al 1974), were described to be genes/proteins of which the expression increased aBer an heat shock. Heat shock proteins (HSP) were defined as proteins encoded by genes that contain so-‐called “heat shock elements (HSE) in their genes that are regulated by the “heat shock transcripNon factor-‐1 (HSF-‐1)”
Cell Stress and Chaperones: basic concepts -‐ Harm H. Kampinga
3
Morimoto 1998
Originally, heat shock genes (Ritossa, 1962) and later heat shock proteins (Tissieres et al 1974), were described to be genes/proteins of which the expression increased aBer an heat shock.
Nowadays, we know that many situaNons, both physiologically and stressful condiNons can acNvate HSF-‐1
Heat shock proteins (HSP) were defined as proteins encoded by genes that contain so-‐called “heat shock elements (HSE) in their genes that are regulated by the “heat shock transcripNon factor-‐1 (HSF-‐1)”
Cell Stress and Chaperones: basic concepts -‐ Harm H. Kampinga
4
Originally, heat shock genes (Ritossa, 1962) and later heat shock proteins (Tissieres et al 1974), were described to be genes/proteins of which the expression increased aBer an heat shock.
Nowadays, we know that many situaNons, both physiologically and stressful condiNons can acNvate HSF-‐1There are many members in at least 5 different heat shock proteins families (HSP90, HSP70, HSP40, chaperonins, and small HSP).
Heat shock proteins (HSP) were defined as proteins encoded by genes that contain so-‐called “heat shock elements (HSE) in their genes that are regulated by the “heat shock transcripNon factor-‐1 (HSF-‐1)”
Kampinga et al., Cell Stress Chaperones. (2009) .
Chaperonins
(HspD/E+ CCT: 2+12 members)
sHsp
(HspB: 10 members)
Hsp70
(HspA+H: 13+4 members)
Hsp90
(HspC: 5 members)
Hsp40
(DnaJ: 50 members)
Cell Stress and Chaperones: basic concepts -‐ Harm H. Kampinga
5
Cell Stress and Chaperones: basic concepts -‐ Harm H. Kampinga
HSP belong to the group of Molecular Chaperones
6
A chaperone is an adult or typically older person who accompanies or supervises one or more young, unmarried men or women during social occasions usually with the specific intent of prevenNng inappropriate social or sexual interacNons or illegal behavior
(e.g., underage drinking, drug use).
Cell Stress and Chaperones: basic concepts -‐ Harm H. Kampinga
HSP belong to the group of Molecular Chaperones
6
A chaperone is an adult or typically older person who accompanies or supervises one or more young, unmarried men or women during social occasions usually with the specific intent of prevenNng inappropriate social or sexual interacNons or illegal behavior
(e.g., underage drinking, drug use).
Cell Stress and Chaperones: basic concepts -‐ Harm H. Kampinga
HSP belong to the group of Molecular Chaperones
6
A chaperone is an adult or typically older person who accompanies or supervises one or more young, unmarried men or women during social occasions usually with the specific intent of prevenNng inappropriate social or sexual interacNons or illegal behavior
(e.g., underage drinking, drug use).
Cell Stress and Chaperones: basic concepts -‐ Harm H. Kampinga
HSP belong to the group of Molecular Chaperones
6
A chaperone is an adult or typically older person who accompanies or supervises one or more young, unmarried men or women during social occasions usually with the specific intent of prevenNng inappropriate social or sexual interacNons or illegal behavior
(e.g., underage drinking, drug use).
Cell Stress and Chaperones: basic concepts -‐ Harm H. Kampinga
HSP belong to the group of Molecular Chaperones
6
Cell Stress and Chaperones: basic concepts -‐ Harm H. Kampinga
HSP belong to the group of Molecular Chaperones
DefiniNon: any protein (HSP being the largest group), which interacts, stabilizes or helps a non-‐naNve protein to acquire its na?ve conforma?on but is not present in the final funcNonal structure
7
Cell Stress and Chaperones: basic concepts -‐ Harm H. Kampinga
HSP belong to the group of Molecular Chaperones
DefiniNon: any protein (HSP being the largest group), which interacts, stabilizes or helps a non-‐naNve protein to acquire its na?ve conforma?on but is not present in the final funcNonal structure
7
Cell Stress and Chaperones: basic concepts -‐ Harm H. Kampinga
HSP belong to the group of Molecular Chaperones
DefiniNon: any protein (HSP being the largest group), which interacts, stabilizes or helps a non-‐naNve protein to acquire its na?ve conforma?on but is not present in the final funcNonal structure
7
Cell Stress and Chaperones: basic concepts -‐ Harm H. Kampinga
HSP belong to the group of Molecular Chaperones
DefiniNon: any protein (HSP being the largest group), which interacts, stabilizes or helps a non-‐naNve protein to acquire its na?ve conforma?on but is not present in the final funcNonal structure
7
Cell Stress and Chaperones: basic concepts -‐ Harm H. Kampinga
HSP belong to the group of Molecular Chaperones
DefiniNon: any protein (HSP being the largest group), which interacts, stabilizes or helps a non-‐naNve protein to acquire its na?ve conforma?on but is not present in the final funcNonal structure
8
Cell Stress and Chaperones: basic concepts -‐ Harm H. Kampinga
HSP belong to the group of Molecular Chaperones
DefiniNon: any protein (HSP being the largest group), which interacts, stabilizes or helps a non-‐naNve protein to acquire its na?ve conforma?on but is not present in the final funcNonal structure
8
The basic chaperone acNon comprise an iteraNve cycles of client binding to and release from HSPs in which clients may fold or may be degraded if folding is not successful
Kampinga & Craig - Nature Reviews | Molecular Cell Biology
Cell Stress and Chaperones: basic concepts -‐ Harm H. Kampinga
HSP belong to the group of Molecular Chaperones
DefiniNon: any protein (HSP being the largest group), which interacts, stabilizes or helps a non-‐naNve protein to acquire its na?ve conforma?on but is not present in the final funcNonal structure
9
The basic chaperone acNon comprise an iteraNve cycles of client binding to and release from HSPs in which clients may fold or may be degraded if folding is not successful
Kampinga & Craig - Nature Reviews | Molecular Cell Biology
Cell Stress and Chaperones: basic concepts -‐ Harm H. Kampinga
HSP belong to the group of Molecular Chaperones
Such acNon is required for assisted folding of nascent proteins and for protein translocaNon (consNtuNvely expressed HSP) and for refolding of stress-‐unfolded proteins (consNtuNve and heat-‐inducible HSP).
DefiniNon: any protein (HSP being the largest group), which interacts, stabilizes or helps a non-‐naNve protein to acquire its na?ve conforma?on but is not present in the final funcNonal structure
9
The basic chaperone acNon comprise an iteraNve cycles of client binding to and release from HSPs in which clients may fold or may be degraded if folding is not successful
Kampinga & Craig - Nature Reviews | Molecular Cell Biology
Cell Stress and Chaperones: basic concepts -‐ Harm H. Kampinga
HSP belong to the group of Molecular Chaperones
nascent
Such acNon is required for assisted folding of nascent proteins and for protein translocaNon (consNtuNvely expressed HSP) and for refolding of stress-‐unfolded proteins (consNtuNve and heat-‐inducible HSP).
DefiniNon: any protein (HSP being the largest group), which interacts, stabilizes or helps a non-‐naNve protein to acquire its na?ve conforma?on but is not present in the final funcNonal structure
9
The basic chaperone acNon comprise an iteraNve cycles of client binding to and release from HSPs in which clients may fold or may be degraded if folding is not successful
Native stress
Kampinga & Craig - Nature Reviews | Molecular Cell Biology
Cell Stress and Chaperones: basic concepts -‐ Harm H. Kampinga
HSP belong to the group of Molecular Chaperones
nascent
Such acNon is required for assisted folding of nascent proteins and for protein translocaNon (consNtuNvely expressed HSP) and for refolding of stress-‐unfolded proteins (consNtuNve and heat-‐inducible HSP).
DefiniNon: any protein (HSP being the largest group), which interacts, stabilizes or helps a non-‐naNve protein to acquire its na?ve conforma?on but is not present in the final funcNonal structure
9
The basic chaperone acNon comprise an iteraNve cycles of client binding to and release from HSPs in which clients may fold or may be degraded if folding is not successful
Cell Stress and Chaperones: basic concepts -‐ Harm H. Kampinga
HSP belong to the group of Molecular Chaperones
Such acNon is required for assisted folding of nascent proteins and for protein translocaNon (consNtuNvely expressed HSP) and for refolding of stress-‐unfolded proteins (consNtuNve and heat-‐inducible HSP).
DefiniNon: any protein (HSP being the largest group), which interacts, stabilizes or helps a non-‐naNve protein to acquire its na?ve conforma?on but is not present in the final funcNonal structure
Heat-‐induced HSP up-‐regulaNon (e.g. Hsp70) thus protects cells against the toxicity of subsequent heaNng (thermotolerance).
10
The basic chaperone acNon comprise an iteraNve cycles of client binding to and release from HSPs in which clients may fold or may be degraded if folding is not successful
Cell Stress and Chaperones: basic concepts -‐ Harm H. Kampinga
HSP belong to the group of Molecular Chaperones
Such acNon is required for assisted folding of nascent proteins and for protein translocaNon (consNtuNvely expressed HSP) and for refolding of stress-‐unfolded proteins (consNtuNve and heat-‐inducible HSP).
DefiniNon: any protein (HSP being the largest group), which interacts, stabilizes or helps a non-‐naNve protein to acquire its na?ve conforma?on but is not present in the final funcNonal structure
Heat-‐induced HSP up-‐regulaNon (e.g. Hsp70) thus protects cells against the toxicity of subsequent heaNng (thermotolerance) and this correlates with increased refolding capacity.
Luciferase
0 1 2hrs after HS
HS0
20
40
60
90
100%
luci
fera
se a
ctiv
ity + HSP
- HSP
11
The basic chaperone acNon comprise an iteraNve cycles of client binding to and release from HSPs in which clients may fold or may be degraded if folding is not successful
Cell Stress and Chaperones: basic concepts -‐ Harm H. Kampinga
HSP belong to the group of Molecular Chaperones
Such acNon is required for assisted folding of nascent proteins and for protein translocaNon (consNtuNvely expressed HSP) and for refolding of stress-‐unfolded proteins (consNtuNve and heat-‐inducible HSP).
DefiniNon: any protein (HSP being the largest group), which interacts, stabilizes or helps a non-‐naNve protein to acquire its na?ve conforma?on but is not present in the final funcNonal structure
Heat-‐induced HSP up-‐regulaNon (e.g. Hsp70) thus protects cells against the toxicity of subsequent heaNng (thermotolerance) and this correlates with increased refolding capacity.
HSP70
chaperone ac*vity
HSP70
toxicity protec*on
Nollen et al | Mol Cell Biol 1999
12
CHAPERONE ACTIVITYin vitro assays
Cell Stress and Chaperones: basic concepts -‐ Harm H. Kampinga
13
CHAPERONE ACTIVITYin vitro assays
Cell Stress and Chaperones: basic concepts -‐ Harm H. Kampinga
1. heat substrate +/-‐ HSP2. measure substrate aggrega*on
13
CHAPERONE ACTIVITYin vitro assays
Cell Stress and Chaperones: basic concepts -‐ Harm H. Kampinga
1. heat substrate +/-‐ HSP2. measure substrate aggrega*on
light sca<eringclient: HSP
1:0
1:1
1:21:5
13
CHAPERONE ACTIVITYin vitro assays
Cell Stress and Chaperones: basic concepts -‐ Harm H. Kampinga
1. heat substrate +/-‐ HSP2. measure substrate aggrega*on
1. heat substrate +/-‐ HSP2. reincubate at 37oC +/-‐ HSP and +/-‐ ATP
3. measure ac*vity
light sca<eringclient: HSP
1:0
1:1
1:21:5
13
ac=vity assaysclient: HSP / ATP
1:0 / no ATP
1:5 / no ATP
1:1 / with ATP
1:2 / with ATP
1:5 / with ATP
CHAPERONE ACTIVITYin vitro assays
Cell Stress and Chaperones: basic concepts -‐ Harm H. Kampinga
1. heat substrate +/-‐ HSP2. measure substrate aggrega*on
1. heat substrate +/-‐ HSP2. reincubate at 37oC +/-‐ HSP and +/-‐ ATP
3. measure ac*vity
light sca<eringclient: HSP
1:0
1:1
1:21:5
13
ac=vity assaysclient: HSP / ATP
1:0 / no ATP
1:5 / no ATP
1:1 / with ATP
1:2 / with ATP
1:5 / with ATP
CHAPERONE ACTIVITYin vitro assays
Cell Stress and Chaperones: basic concepts -‐ Harm H. Kampinga
aggrega?on preven?on(“holdase”)
1. heat substrate +/-‐ HSP2. measure substrate aggrega*on
1. heat substrate +/-‐ HSP2. reincubate at 37oC +/-‐ HSP and +/-‐ ATP
3. measure ac*vity
light sca<eringclient: HSP
1:0
1:1
1:21:5
13
ac=vity assaysclient: HSP / ATP
1:0 / no ATP
1:5 / no ATP
1:1 / with ATP
1:2 / with ATP
1:5 / with ATP
CHAPERONE ACTIVITYin vitro assays
Cell Stress and Chaperones: basic concepts -‐ Harm H. Kampinga
aggrega?on preven?on(“holdase”)
suppor?ng refolding(“foldase”)
1. heat substrate +/-‐ HSP2. measure substrate aggrega*on
1. heat substrate +/-‐ HSP2. reincubate at 37oC +/-‐ HSP and +/-‐ ATP
3. measure ac*vity
light sca<eringclient: HSP
1:0
1:1
1:21:5
13
CHAPERONE ACTIVITY
Hsp60/10
(HspD/E)
sHsp
(HspB)
Hsp70
(HspA)
Hsp90
(HspC)
Hsp40
(DnaJ)
Cell Stress and Chaperones: basic concepts -‐ Harm H. Kampinga
14
CHAPERONE ACTIVITY
Hsp60/10
(HspD/E)
sHsp
(HspB)
Hsp70
(HspA)
Hsp90
(HspC)
Hsp40
(DnaJ)
ATP-independent‘holders’
Cell Stress and Chaperones: basic concepts -‐ Harm H. Kampinga
14
CHAPERONE ACTIVITY
Hsp60/10
(HspD/E)
sHsp
(HspB)
Hsp70
(HspA)
Hsp90
(HspC)
Hsp40
(DnaJ)
ATP-independent‘holders’
ATP-dependent‘holders & folders’
Cell Stress and Chaperones: basic concepts -‐ Harm H. Kampinga
14
The Hsp70 machine
CHAPERONE ACTIVITY
Hsp60/10
(HspD/E)
sHsp
(HspB)
Hsp70
(HspA)
Hsp90
(HspC)
Hsp40
(DnaJ)
ATP-independent‘holders’
ATP-dependent‘holders & folders’
Cell Stress and Chaperones: basic concepts -‐ Harm H. Kampinga
14
CHAPERONE ACTIVITYThe Hsp70 machine
Cell Stress and Chaperones: basic concepts -‐ Harm H. Kampinga
15
Kampinga & Craig - Nature Reviews | Molecular Cell Biology
CHAPERONE ACTIVITYThe Hsp70 machine
Cell Stress and Chaperones: basic concepts -‐ Harm H. Kampinga
16
CHAPERONE ACTIVITYHsp90
Cell Stress and Chaperones: basic concepts -‐ Harm H. Kampinga
Mayer et et al. 200217
CHAPERONE ACTIVITYHsp90
Cell Stress and Chaperones: basic concepts -‐ Harm H. Kampinga
Mayer et et al. 200218
CHAPERONE ACTIVITYGroEL/ES (Hsp60/10)
Cell Stress and Chaperones: basic concepts -‐ Harm H. Kampinga
Ranson et al. 2001 Ranford et al. 2000
19
CHAPERONE ACTIVITYGroEL/ES (Hsp60/10)
Cell Stress and Chaperones: basic concepts -‐ Harm H. Kampinga
Tang et al. 2006 20
CHAPERONE ACTIVITYsmall Hsp
Cell Stress and Chaperones: basic concepts -‐ Harm H. Kampinga
Jaya et al. 20069Kim et al 199821
CHAPERONE ACTIVITYsmall Hsp
Cell Stress and Chaperones: basic concepts -‐ Harm H. Kampinga
Teydmer et al 2011
22
Kampinga & Craig - Nature Reviews | Molecular Cell Biology
HSPC
CHAPERONE NETWORK
Cell Stress and Chaperones: basic concepts -‐ Harm H. Kampinga
23
Kampinga & Craig - Nature Reviews | Molecular Cell Biology
HSPC
HSPD/E
Cell Stress and Chaperones: basic concepts -‐ Harm H. Kampinga
CHAPERONE NETWORK
24
Kampinga & Craig - Nature Reviews | Molecular Cell Biology
HSPC
HSPD/E
HSPB
Cell Stress and Chaperones: basic concepts -‐ Harm H. Kampinga
CHAPERONE NETWORK
25
Originally, heat shock genes (Ritossa, 1962) and later heat shock proteins (Tissieres et al 1974), were described to be genes/proteins of which the expression increased aBer an heat shock.
Nowadays, we know that many situaNon, both physiologically and stressful condiNons can acNvate HSF-‐1There are many members in at least 5 different heat shock proteins families (HSP90, HSP70, HSP40, chaperonins, and small HSP) that work in a cellular network.
Heat shock proteins (HSP) were defined as proteins encoded by genes that contain so-‐called “heat shock elements (HSE) in their genes that are regulated by the “heat shock transcripNon factor-‐1 (HSF-‐1)”
Kampinga et al., Cell Stress Chaperones. (2009) .
Chaperonins
(HspD/E+ CCT: 2+12 members)
sHsp
(HspB: 10 members)
Hsp70
(HspA+H: 13+4 members)
Hsp90
(HspC: 5 members)
Hsp40
(DnaJ: 50 members)
Cell Stress and Chaperones: basic concepts -‐ Harm H. Kampinga
26
Originally, heat shock genes (Ritossa, 1962) and later heat shock proteins (Tissieres et al 1974), were described to be genes/proteins of which the expression increased aBer an heat shock.
Nowadays, we know that many situaNon, both physiologically and stressful condiNons can acNvate HSF-‐1There are many members in at least 5 different heat shock proteins families (HSP90, HSP70, HSP40, chaperonins, and small HSP) that work in a cellular network.
Heat shock proteins (HSP) were defined as proteins encoded by genes that contain so-‐called “heat shock elements (HSE) in their genes that are regulated by the “heat shock transcripNon factor-‐1 (HSF-‐1)”
Kampinga et al., Cell Stress Chaperones. (2009) .
Chaperonins
(HspD/E+ CCT: 2+12 members)
sHsp
(HspB: 10 members)
Hsp70
(HspA+H: 13+4 members)
Hsp90
(HspC: 5 members)
Hsp40
(DnaJ: 50 members)
Cell Stress and Chaperones: basic concepts -‐ Harm H. Kampinga
But why do humans have so many HSPs?
26
Originally, heat shock genes (Ritossa, 1962) and later heat shock proteins (Tissieres et al 1974), were described to be genes/proteins of which the expression increased aBer an heat shock.
Nowadays, we know that many situaNon, both physiologically and stressful condiNons can acNvate HSF-‐1There are many members in at least 5 different heat shock proteins families (HSP90, HSP70, HSP40, chaperonins, and small HSP) that work in a cellular network.
Heat shock proteins (HSP) were defined as proteins encoded by genes that contain so-‐called “heat shock elements (HSE) in their genes that are regulated by the “heat shock transcripNon factor-‐1 (HSF-‐1)”
Kampinga et al., Cell Stress Chaperones. (2009) .
Chaperonins
(HspD/E+ CCT: 2+12 members)
sHsp
(HspB: 10 members)
Hsp70
(HspA+H: 13+4 members)
Hsp90
(HspC: 5 members)
Hsp40
(DnaJ: 50 members)
Cell Stress and Chaperones: basic concepts -‐ Harm H. Kampinga
But why do humans have so many HSPs?1. compartmentalization (cyt/nuc-HSR; ER-UPR; mit-UPR; Per-UPR?)
26
Originally, heat shock genes (Ritossa, 1962) and later heat shock proteins (Tissieres et al 1974), were described to be genes/proteins of which the expression increased aBer an heat shock.
Nowadays, we know that many situaNon, both physiologically and stressful condiNons can acNvate HSF-‐1There are many members in at least 5 different heat shock proteins families (HSP90, HSP70, HSP40, chaperonins, and small HSP) that work in a cellular network.
Heat shock proteins (HSP) were defined as proteins encoded by genes that contain so-‐called “heat shock elements (HSE) in their genes that are regulated by the “heat shock transcripNon factor-‐1 (HSF-‐1)”
Kampinga et al., Cell Stress Chaperones. (2009) .
Chaperonins
(HspD/E+ CCT: 2+12 members)
sHsp
(HspB: 10 members)
Hsp70
(HspA+H: 13+4 members)
Hsp90
(HspC: 5 members)
Hsp40
(DnaJ: 50 members)
Cell Stress and Chaperones: basic concepts -‐ Harm H. Kampinga
But why do humans have so many HSPs?1. compartmentalization (cyt/nuc-HSR; ER-UPR; mit-UPR; Per-UPR?)
2. differential regulation (e.g., many HSPs are NOT heat-/HSF-1 regulated)
26
Hageman et al 2011 .
Cell Stress and Chaperones: basic concepts -‐ Harm H. Kampinga
But why do humans have so many HSPs?1. compartmentalization (cyt/nuc-HSR; ER-UPR; mit-UPR; Per-UPR?)
2. differential regulation (e.g., many HSPs are NOT heat-/HSF-1 regulated)
DNAJB5 = 0.1%
DNAJB6 = 2.3%
DNAJB7 = 0.3%
DNAJA1 = 4.2%
DNAJA2 = 1.4%
DNAJA3 = 2.3%
DNAJA4 = 0.0%
DNAJB1 = 2.8%
GAPD = 82.9%
DNAJB2 = 0.0%
DNAJB4 = 0.3%
DNAJB8 = 0.0%
DNAJB9 = 0.2%
DNAJB11 = 2.4%
DNAJB12 = 0.7%
-HS
HS
DNAJA1 = 2.5%
DNAJA2 = 0.4%
DNAJA3 = 0.4%
DNAJA4 = 0.0%
DNAJB2 = 0.0%
DNAJB4 = 0.6%
DNAJB5 = 0.0%
DNAJB6 = 2.4%
DNAJB7 = 0.1%
DNAJB8 = 0.0%
DNAJB9 = 0.3%
DNAJB11 = 2.0%
DNAJB12 = 0.1%
DNAJB1 = 62.1%
GAPD = 29.0%
+HS
27
Kampinga et al., Cell Stress Chaperones. (2009) .
Chaperonins
(HspD/E+ CCT: 2+12 members)
sHsp
(HspB: 10 members)
Hsp70
(HspA+H: 13+4 members)
Hsp90
(HspC: 5 members)
Hsp40
(DnaJ: 50 members)
Cell Stress and Chaperones: basic concepts -‐ Harm H. Kampinga
But why do humans have so many HSPs?1. compartmentalization (cyt/nuc-HSR; ER-UPR; mit-UPR; Per-UPR?)
2. differential regulation (e.g., many HSPs are NOT heat-/HSF-1 regulated)
3. functional specificity (structural differences)
28
Kampinga et al., Cell Stress Chaperones. (2009) .
Chaperonins
(HspD/E+ CCT: 2+12 members)
sHsp
(HspB: 10 members)
Hsp70
(HspA+H: 13+4 members)
Hsp90
(HspC: 5 members)
Hsp40
(DnaJ: 50 members)
Cell Stress and Chaperones: basic concepts -‐ Harm H. Kampinga
But why do humans have so many HSPs?1. compartmentalization (cyt/nuc-HSR; ER-UPR; mit-UPR; Per-UPR?)
2. differential regulation (e.g., many HSPs are NOT heat-/HSF-1 regulated)
3. functional specificity (structural differences)
28
Kampinga & Craig - Nature Reviews | Molecular Cell Biology
FUNCTIONAL SPECIFICITY OF THE HSP70 MACHINE
Cell Stress and Chaperones: basic concepts -‐ Harm H. Kampinga
29
The Hsp70 machine is involved in many different biochemical and biological funcNons ranging from co-‐translaNonal folding, to protein translocaNon across membranes, from protein
remodeling to protein degradaNon.
Kampinga & Craig - Nature Reviews | Molecular Cell Biology
FUNCTIONAL SPECIFICITY OF THE HSP70 MACHINE
Cell Stress and Chaperones: basic concepts -‐ Harm H. Kampinga
29
The Hsp70 machine is involved in many different biochemical and biological funcNons ranging from co-‐translaNonal folding, to protein translocaNon across membranes, from protein
remodeling to protein degradaNon.
1. Role expansion HSP70 family
Kampinga & Craig - Nature Reviews | Molecular Cell Biology
FUNCTIONAL SPECIFICITY OF THE HSP70 MACHINE
Cell Stress and Chaperones: basic concepts -‐ Harm H. Kampinga
29
The Hsp70 machine is involved in many different biochemical and biological funcNons ranging from co-‐translaNonal folding, to protein translocaNon across membranes, from protein
remodeling to protein degradaNon.
1. Role expansion HSP70 family
Ssa1-4; Ssb1,2 HSPA1,2,6,7,8Kar2 HSPA5Ssc1;SSq1;Emc10
Yeast Human 0 200 400 600 800 1000
HSPA9HSPA12A,B
Ssz1 HSPA14
Hsp70
Cytosol
ER
Cytosol
Cytosol
Mitochondria
Kampinga & Craig - Nature Reviews | Molecular Cell Biology
FUNCTIONAL SPECIFICITY OF THE HSP70 MACHINE
Cell Stress and Chaperones: basic concepts -‐ Harm H. Kampinga
29
The Hsp70 machine is involved in many different biochemical and biological funcNons ranging from co-‐translaNonal folding, to protein translocaNon across membranes, from protein
remodeling to protein degradaNon.
1. Role expansion HSP70 family
Ssa1-4; Ssb1,2 HSPA1,2,6,7,8Kar2 HSPA5Ssc1;SSq1;Emc10
Yeast Human 0 200 400 600 800 1000
HSPA9HSPA12A,B
Ssz1 HSPA14
Hsp70
Cytosol
ER
Cytosol
Cytosol
Mitochondria
Kampinga & Craig - Nature Reviews | Molecular Cell Biology
Hsp70 are structural almost idenNcal (same domain structure) Hsp70 show all similar biochemical acNvity (an ATP-‐dependent client protein binding/release cycle).
Except HSPA14 that lacks substrate binding
FUNCTIONAL SPECIFICITY OF THE HSP70 MACHINE
Cell Stress and Chaperones: basic concepts -‐ Harm H. Kampinga
29
Kampinga & Craig - Nature Reviews | Molecular Cell Biology
The Hsp70 machine is involved in many different biochemical and biological funcNons ranging from co-‐translaNonal folding, to protein translocaNon across membranes, from protein
remodeling to protein degradaNon.
FUNCTIONAL SPECIFICITY OF THE HSP70 MACHINE
Cell Stress and Chaperones: basic concepts -‐ Harm H. Kampinga
30
Kampinga & Craig - Nature Reviews | Molecular Cell Biology
The Hsp70 machine is involved in many different biochemical and biological funcNons ranging from co-‐translaNonal folding, to protein translocaNon across membranes, from protein
remodeling to protein degradaNon.
FUNCTIONAL SPECIFICITY OF THE HSP70 MACHINE
Cell Stress and Chaperones: basic concepts -‐ Harm H. Kampinga
2. Role expansion DNAJ protein family
30
0Yeast Human 100 200 300 400 500 600
Ydj1 DNAJA1
DNAJA3
Xdj1 DNAJA2;A4
DNAJB4;B5DNAJB11DNAJB9DNAJB2a,2b
DNAJB6a,6b
DNAJB12a,12bDNAJB14a,14bDNAJC18
DNAJC21Jjj1DNAJC24
DNAJC10DNAJC16
DNAJC26DNAJC27DNAJC3DNAJC7
DNAJC29DNAJC14DNAJC22
DNAJB13
Jjj3DNAJC5,5b,5g
DNAJB8DNAJB7
Apj1Scj1Mdj1
DNAJB1Sis1
DNAJC20Jac1
Jem1
DNAJC17Cwc23
Swa2
Djp1Caj1
Erj5
Promiscous client binding
Selective client binding
Client binding unclear
590/531
793
782
45794306
702
DNAJC6668
913
1311
0Yeast Human 100 200 300 400 500 600
Ydj1 DNAJA1
DNAJA3
Xdj1 DNAJA2;A4
DNAJB4;B5DNAJB11DNAJB9DNAJB2a,2b
DNAJB6a,6b
DNAJB12a,12bDNAJB14a,14bDNAJC18
DNAJC21Jjj1DNAJC24
DNAJC10DNAJC16
DNAJC26DNAJC27DNAJC3DNAJC7
DNAJC29DNAJC14DNAJC22
DNAJB13
Jjj3DNAJC5,5b,5g
DNAJB8DNAJB7
Apj1Scj1Mdj1
DNAJB1Sis1
DNAJC20Jac1
Jem1
DNAJC17Cwc23
Swa2
Djp1Caj1
Erj5
Promiscous client binding
Selective client binding
Client binding unclear
590/531
793
782
45794306
702
DNAJC6668
913
1311
FuncNonal classificaNon DNAJ proteins1: Client binding and client delivery to Hsp70
a) promiscuous client bindingb) selecNve client binding
2: No client binding, just ATPase sNmulaNona) tethering Hsp70 to a locaNon/ a posiNonb) no tethering
The Hsp70 machine is involved in many different biochemical and biological funcNons ranging from co-‐translaNonal folding, to protein translocaNon across membranes, from protein
remodeling to protein degradaNon.
2. Role expansion DNAJ protein family
FUNCTIONAL SPECIFICITY OF THE HSP70 MACHINE
Cell Stress and Chaperones: basic concepts -‐ Harm H. Kampinga
Kampinga & Craig - Nature Reviews | Molecular Cell Biology
31
0Yeast Human 100 200 300 400 500 600
Ydj1 DNAJA1
DNAJA3
Xdj1 DNAJA2;A4
DNAJB4;B5DNAJB11DNAJB9DNAJB2a,2b
DNAJB6a,6b
DNAJB12a,12bDNAJB14a,14bDNAJC18
DNAJC21Jjj1DNAJC24
DNAJC10DNAJC16
DNAJC26DNAJC27DNAJC3DNAJC7
DNAJC29DNAJC14DNAJC22
DNAJB13
Jjj3DNAJC5,5b,5g
DNAJB8DNAJB7
Apj1Scj1Mdj1
DNAJB1Sis1
DNAJC20Jac1
Jem1
DNAJC17Cwc23
Swa2
Djp1Caj1
Erj5
Promiscous client binding
Selective client binding
Client binding unclear
590/531
793
782
45794306
702
DNAJC6668
913
1311
0Yeast Human 100 200 300 400 500 600
Ydj1 DNAJA1
DNAJA3
Xdj1 DNAJA2;A4
DNAJB4;B5DNAJB11DNAJB9DNAJB2a,2b
DNAJB6a,6b
DNAJB12a,12bDNAJB14a,14bDNAJC18
DNAJC21Jjj1DNAJC24
DNAJC10DNAJC16
DNAJC26DNAJC27DNAJC3DNAJC7
DNAJC29DNAJC14DNAJC22
DNAJB13
Jjj3DNAJC5,5b,5g
DNAJB8DNAJB7
Apj1Scj1Mdj1
DNAJB1Sis1
DNAJC20Jac1
Jem1
DNAJC17Cwc23
Swa2
Djp1Caj1
Erj5
Promiscous client binding
Selective client binding
Client binding unclear
590/531
793
782
45794306
702
DNAJC6668
913
1311
FuncNonal classificaNon DNAJ proteins1: Client binding and client delivery to Hsp70
a) promiscuous client bindingb) selecNve client binding
2: No client binding, just ATPase sNmulaNona) tethering Hsp70 to a locaNon/ a posiNonb) no tethering
The Hsp70 machine is involved in many different biochemical and biological funcNons ranging from co-‐translaNonal folding, to protein translocaNon across membranes, from protein
remodeling to protein degradaNon.
2. Role expansion DNAJ protein family
FUNCTIONAL SPECIFICITY OF THE HSP70 MACHINE
Cell Stress and Chaperones: basic concepts -‐ Harm H. Kampinga
Kampinga & Craig - Nature Reviews | Molecular Cell Biology
31
0Yeast Human 100 200 300 400 500 600
Ydj1 DNAJA1
DNAJA3
Xdj1 DNAJA2;A4
DNAJB4;B5DNAJB11DNAJB9DNAJB2a,2b
DNAJB6a,6b
DNAJB12a,12bDNAJB14a,14bDNAJC18
DNAJC21Jjj1DNAJC24
DNAJC10DNAJC16
DNAJC26DNAJC27DNAJC3DNAJC7
DNAJC29DNAJC14DNAJC22
DNAJB13
Jjj3DNAJC5,5b,5g
DNAJB8DNAJB7
Apj1Scj1Mdj1
DNAJB1Sis1
DNAJC20Jac1
Jem1
DNAJC17Cwc23
Swa2
Djp1Caj1
Erj5
Promiscous client binding
Selective client binding
Client binding unclear
590/531
793
782
45794306
702
DNAJC6668
913
1311
0Yeast Human 100 200 300 400 500 600
Ydj1 DNAJA1
DNAJA3
Xdj1 DNAJA2;A4
DNAJB4;B5DNAJB11DNAJB9DNAJB2a,2b
DNAJB6a,6b
DNAJB12a,12bDNAJB14a,14bDNAJC18
DNAJC21Jjj1DNAJC24
DNAJC10DNAJC16
DNAJC26DNAJC27DNAJC3DNAJC7
DNAJC29DNAJC14DNAJC22
DNAJB13
Jjj3DNAJC5,5b,5g
DNAJB8DNAJB7
Apj1Scj1Mdj1
DNAJB1Sis1
DNAJC20Jac1
Jem1
DNAJC17Cwc23
Swa2
Djp1Caj1
Erj5
Promiscous client binding
Selective client binding
Client binding unclear
590/531
793
782
45794306
702
DNAJC6668
913
1311
FuncNonal classificaNon DNAJ proteins1: Client binding and client delivery to Hsp70
a) promiscuous client bindingb) selecNve client binding
2: No client binding, just ATPase sNmulaNona) tethering Hsp70 to a locaNon/ a posiNonb) no tethering
The Hsp70 machine is involved in many different biochemical and biological funcNons ranging from co-‐translaNonal folding, to protein translocaNon across membranes, from protein
remodeling to protein degradaNon.
2. Role expansion DNAJ protein family
FUNCTIONAL SPECIFICITY OF THE HSP70 MACHINE
Cell Stress and Chaperones: basic concepts -‐ Harm H. Kampinga
Kampinga & Craig - Nature Reviews | Molecular Cell Biology
31
0Yeast Human 100 200 300 400 500 600
Ydj1 DNAJA1
DNAJA3
Xdj1 DNAJA2;A4
DNAJB4;B5DNAJB11DNAJB9DNAJB2a,2b
DNAJB6a,6b
DNAJB12a,12bDNAJB14a,14bDNAJC18
DNAJC21Jjj1DNAJC24
DNAJC10DNAJC16
DNAJC26DNAJC27DNAJC3DNAJC7
DNAJC29DNAJC14DNAJC22
DNAJB13
Jjj3DNAJC5,5b,5g
DNAJB8DNAJB7
Apj1Scj1Mdj1
DNAJB1Sis1
DNAJC20Jac1
Jem1
DNAJC17Cwc23
Swa2
Djp1Caj1
Erj5
Promiscous client binding
Selective client binding
Client binding unclear
590/531
793
782
45794306
702
DNAJC6668
913
1311
0Yeast Human 100 200 300 400 500 600
Ydj1 DNAJA1
DNAJA3
Xdj1 DNAJA2;A4
DNAJB4;B5DNAJB11DNAJB9DNAJB2a,2b
DNAJB6a,6b
DNAJB12a,12bDNAJB14a,14bDNAJC18
DNAJC21Jjj1DNAJC24
DNAJC10DNAJC16
DNAJC26DNAJC27DNAJC3DNAJC7
DNAJC29DNAJC14DNAJC22
DNAJB13
Jjj3DNAJC5,5b,5g
DNAJB8DNAJB7
Apj1Scj1Mdj1
DNAJB1Sis1
DNAJC20Jac1
Jem1
DNAJC17Cwc23
Swa2
Djp1Caj1
Erj5
Promiscous client binding
Selective client binding
Client binding unclear
590/531
793
782
45794306
702
DNAJC6668
913
1311
FuncNonal classificaNon DNAJ proteins1: Client binding and client delivery to Hsp70
a) promiscuous client bindingb) selecNve client binding
2: No client binding, just ATPase sNmulaNona) tethering Hsp70 to a locaNon/ a posiNonb) no tethering
The Hsp70 machine is involved in many different biochemical and biological funcNons ranging from co-‐translaNonal folding, to protein translocaNon across membranes, from protein
remodeling to protein degradaNon.
2. Role expansion DNAJ protein family
FUNCTIONAL SPECIFICITY OF THE HSP70 MACHINE
Cell Stress and Chaperones: basic concepts -‐ Harm H. Kampinga
Kampinga & Craig - Nature Reviews | Molecular Cell Biology
31
0Yeast Human 100 200 300 400 500 600
Ydj1 DNAJA1
DNAJA3
Xdj1 DNAJA2;A4
DNAJB4;B5DNAJB11DNAJB9DNAJB2a,2b
DNAJB6a,6b
DNAJB12a,12bDNAJB14a,14bDNAJC18
DNAJC21Jjj1DNAJC24
DNAJC10DNAJC16
DNAJC26DNAJC27DNAJC3DNAJC7
DNAJC29DNAJC14DNAJC22
DNAJB13
Jjj3DNAJC5,5b,5g
DNAJB8DNAJB7
Apj1Scj1Mdj1
DNAJB1Sis1
DNAJC20Jac1
Jem1
DNAJC17Cwc23
Swa2
Djp1Caj1
Erj5
Promiscous client binding
Selective client binding
Client binding unclear
590/531
793
782
45794306
702
DNAJC6668
913
1311
0Yeast Human 100 200 300 400 500 600
Ydj1 DNAJA1
DNAJA3
Xdj1 DNAJA2;A4
DNAJB4;B5DNAJB11DNAJB9DNAJB2a,2b
DNAJB6a,6b
DNAJB12a,12bDNAJB14a,14bDNAJC18
DNAJC21Jjj1DNAJC24
DNAJC10DNAJC16
DNAJC26DNAJC27DNAJC3DNAJC7
DNAJC29DNAJC14DNAJC22
DNAJB13
Jjj3DNAJC5,5b,5g
DNAJB8DNAJB7
Apj1Scj1Mdj1
DNAJB1Sis1
DNAJC20Jac1
Jem1
DNAJC17Cwc23
Swa2
Djp1Caj1
Erj5
Promiscous client binding
Selective client binding
Client binding unclear
590/531
793
782
45794306
702
DNAJC6668
913
1311
FuncNonal classificaNon DNAJ proteins1: Client binding and client delivery to Hsp70
a) promiscuous client bindingb) selecNve client binding
2: No client binding, just ATPase sNmulaNona) tethering Hsp70 to a locaNon/ a posiNonb) no tethering
The Hsp70 machine is involved in many different biochemical and biological funcNons ranging from co-‐translaNonal folding, to protein translocaNon across membranes, from protein
remodeling to protein degradaNon.
2. Role expansion DNAJ protein family
FUNCTIONAL SPECIFICITY OF THE HSP70 MACHINE
Cell Stress and Chaperones: basic concepts -‐ Harm H. Kampinga
Kampinga & Craig - Nature Reviews | Molecular Cell Biology
31
Even within “promiscuous client binders”, there are large structural differences
J-domainG/F rich domainCTD1 with ZFLRCTD2Dimerization domain
Putative CTD2CTD1 lacking ZFLR
TransmembranedomainPutative CTD1Ubiquitin-interactingmotifCoiled coilCTD1 with HDAC BDUnidenti!ed proteinmotif
0Yeast Human 100 200 300 400 500 600
Ydj1 DNAJA1
DNAJA3
Xdj1 DNAJA2;A4
DNAJB4;B5DNAJB11DNAJB9DNAJB2a,2b
DNAJB6a,6b
DNAJB12a,12bDNAJB14a,14bDNAJC18
DNAJB8DNAJB7
Apj1Scj1Mdj1
DNAJB1Sis1
Djp1Caj1
Erj5
Promiscous client binding
The Hsp70 machine is involved in many different biochemical and biological funcNons ranging from co-‐translaNonal folding, to protein translocaNon across membranes, from protein
remodeling to protein degradaNon.
2. Role expansion DNAJ protein family
FUNCTIONAL SPECIFICITY OF THE HSP70 MACHINE
Cell Stress and Chaperones: basic concepts -‐ Harm H. Kampinga
Kampinga & Craig - Nature Reviews | Molecular Cell Biology
32
Even within “promiscuous client binders”, there are large structural differences
J-domainG/F rich domainCTD1 with ZFLRCTD2Dimerization domain
Putative CTD2CTD1 lacking ZFLR
TransmembranedomainPutative CTD1Ubiquitin-interactingmotifCoiled coilCTD1 with HDAC BDUnidenti!ed proteinmotif
0Yeast Human 100 200 300 400 500 600
Ydj1 DNAJA1
DNAJA3
Xdj1 DNAJA2;A4
DNAJB4;B5DNAJB11DNAJB9DNAJB2a,2b
DNAJB6a,6b
DNAJB12a,12bDNAJB14a,14bDNAJC18
DNAJB8DNAJB7
Apj1Scj1Mdj1
DNAJB1Sis1
Djp1Caj1
Erj5
Promiscous client binding
The Hsp70 machine is involved in many different biochemical and biological funcNons ranging from co-‐translaNonal folding, to protein translocaNon across membranes, from protein
remodeling to protein degradaNon.
2. Role expansion DNAJ protein family
FUNCTIONAL SPECIFICITY OF THE HSP70 MACHINE
Cell Stress and Chaperones: basic concepts -‐ Harm H. Kampinga
Kampinga & Craig - Nature Reviews | Molecular Cell Biology
32
Even within “promiscuous client binders”, there are large structural differences
J-domainG/F rich domainCTD1 with ZFLRCTD2Dimerization domain
Putative CTD2CTD1 lacking ZFLR
TransmembranedomainPutative CTD1Ubiquitin-interactingmotifCoiled coilCTD1 with HDAC BDUnidenti!ed proteinmotif
0Yeast Human 100 200 300 400 500 600
Ydj1 DNAJA1
DNAJA3
Xdj1 DNAJA2;A4
DNAJB4;B5DNAJB11DNAJB9DNAJB2a,2b
DNAJB6a,6b
DNAJB12a,12bDNAJB14a,14bDNAJC18
DNAJB8DNAJB7
Apj1Scj1Mdj1
DNAJB1Sis1
Djp1Caj1
Erj5
Promiscous client binding
The Hsp70 machine is involved in many different biochemical and biological funcNons ranging from co-‐translaNonal folding, to protein translocaNon across membranes, from protein
remodeling to protein degradaNon.
2. Role expansion DNAJ protein family
FUNCTIONAL SPECIFICITY OF THE HSP70 MACHINE
Cell Stress and Chaperones: basic concepts -‐ Harm H. Kampinga
Kampinga & Craig - Nature Reviews | Molecular Cell Biology
32
Westhoff et al., Current Biology 15 (2005) 1058
DNAJB2a,2bJ-domain G/F putative CTD1 UIM UIMJ-domain G/F CTD1 w/o ZnF DDCTD2
Sis1
HSPA1A
C or DNAJB1
HSPA1A + DNAJB1
Michels et al., J. Biol. Chem 1997
DNAJB1: promotes refolding
The Hsp70 machine is involved in many different biochemical and biological funcNons ranging from co-‐translaNonal folding, to protein translocaNon across membranes, from protein
remodeling to protein degradaNon.
2. Role expansion DNAJ protein family
FUNCTIONAL SPECIFICITY OF THE HSP70 MACHINE
Cell Stress and Chaperones: basic concepts -‐ Harm H. Kampinga
Howarth et al., Mol. Ther. 15 (2007) 1100
Aver
age
RLU
(nor
mal
ized
to c
ontro
lun
dena
ture
d va
lues
) 80
60
40
20
00 15 30
Recovery time (minutes)45 60
HSPA1A + DNAJB1
HSPA1A + DNAJB2aHSPA1A + DNAJB2b
control
DNAJB2: promotes degradaNon
33
Cell Stress and Chaperones: basic concepts -‐ Harm H. Kampinga
The Hsp70 machine is involved in many different biochemical and biological funcNons ranging from co-‐translaNonal folding, to protein translocaNon across membranes, from protein
remodeling to protein degradaNon.
2. Role expansion DNAJ protein family-‐ client specificity-‐ client handling
FUNCTIONAL SPECIFICITY OF THE HSP70 MACHINE
Kampinga & Craig - Nature Reviews | Molecular Cell Biology
34
The Hsp70 machine is involved in many different biochemical and biological funcNons ranging from co-‐translaNonal folding, to protein translocaNon across membranes, from protein
remodeling to protein degradaNon.
3. Role expansion NEF protein families
FUNCTIONAL SPECIFICITY OF THE HSP70 MACHINE
Cell Stress and Chaperones: basic concepts -‐ Harm H. Kampinga
Kampinga & Craig - Nature Reviews | Molecular Cell Biology
35
Sse1,2HSPH1,2,3
BAP
BAG1BAG1L
BAG2BAG3BAG4BAG5BAG6
Lhs1
Snl1
HSPH4
HSPBP1Fes1Sil1 (Sls1*)
NEFs Yeast Human 0 200 400 600 800 1000
Three groups nucleoNde exchange factors (NEF) of Hsp70s exist in eukaryotes that show considerable structural divergency.
Since, they generally act at a step aBer substrate recogniNon and cannot bind substrates themselves (except for HSPH), their role seems primarily to
determining client fate, i.e:folding: HSPH and HSPBP1/BAP versus degrada?on: BAG
The Hsp70 machine is involved in many different biochemical and biological funcNons ranging from co-‐translaNonal folding, to protein translocaNon across membranes, from protein
remodeling to protein degradaNon.
3. Role expansion NEF protein families
FUNCTIONAL SPECIFICITY OF THE HSP70 MACHINE
Cell Stress and Chaperones: basic concepts -‐ Harm H. Kampinga
Kampinga & Craig - Nature Reviews | Molecular Cell Biology
36
4. networks interac?ons
The Hsp70 machine is involved in many different biochemical and biological funcNons ranging from co-‐translaNonal folding, to protein translocaNon across membranes, from protein
remodeling to protein degradaNon.
FUNCTIONAL SPECIFICITY OF THE HSP70 MACHINE
Cell Stress and Chaperones: basic concepts -‐ Harm H. Kampinga
Kampinga & Craig - Nature Reviews | Molecular Cell Biology
HSPC
HSPD/E
HSPB
CHIP
HIP
37
4. networks interac?ons
The Hsp70 machine is involved in many different biochemical and biological funcNons ranging from co-‐translaNonal folding, to protein translocaNon across membranes, from protein
remodeling to protein degradaNon.
FUNCTIONAL SPECIFICITY OF THE HSP70 MACHINE
Cell Stress and Chaperones: basic concepts -‐ Harm H. Kampinga
Kampinga & Craig - Nature Reviews | Molecular Cell Biology
HSPC
HSPD/E
HSPB
CHIP
HIP
37
The basic chaperone acNon comprise an iteraNve cycles of client binding to and release from HSPs in which clients may fold or may be degraded if folding is not successful
Cell Stress and Chaperones: basic concepts -‐ Harm H. Kampinga
HSP belong to the group of Molecular Chaperones
Such acNon is required for assisted folding of nascent proteins and for protein translocaNon (consNtuNvely expressed HSP) and for refolding of stress-‐unfolded proteins (consNtuNve and heat-‐inducible HSP).
DefiniNon: any protein (HSP being the largest group), which interacts, stabilizes or helps a non-‐naNve protein to acquire its na?ve conforma?on but is not present in the final funcNonal structure
Heat-‐induced HSP up-‐regulaNon (e.g. Hsp70) thus protects cells against the toxicity of subsequent heaNng (thermotolerance) and this correlates with increased refolding capacity.
The diverse HSP families, their members and mutual interacNons ensure funcNonal specificity to maintain the cellular protein homeostasis (proteostasis)
nascent
Native stress
38
The basic chaperone acNon comprise an iteraNve cycles of client binding to and release from HSPs in which clients may fold or may be degraded if folding is not successful
Cell Stress and Chaperones: basic concepts -‐ Harm H. Kampinga
HSP belong to the group of Molecular Chaperones
Such acNon is required for assisted folding of nascent proteins and for protein translocaNon (consNtuNvely expressed HSP) and for refolding of stress-‐unfolded proteins (consNtuNve and heat-‐inducible HSP).
DefiniNon: any protein (HSP being the largest group), which interacts, stabilizes or helps a non-‐naNve protein to acquire its na?ve conforma?on but is not present in the final funcNonal structure
Heat-‐induced HSP up-‐regulaNon (e.g. Hsp70) thus protects cells against the toxicity of subsequent heaNng (thermotolerance) and this correlates with increased refolding capacity.
The diverse HSP families, their members and mutual interacNons ensure funcNonal specificity to maintain the cellular protein homeostasis (proteostasis)
nascent
Native stress
38
The basic chaperone acNon comprise an iteraNve cycles of client binding to and release from HSPs in which clients may fold or may be degraded if folding is not successful
Cell Stress and Chaperones: basic concepts -‐ Harm H. Kampinga
HSP belong to the group of Molecular Chaperones
Such acNon is required for assisted folding of nascent proteins and for protein translocaNon (consNtuNvely expressed HSP) and for refolding of stress-‐unfolded proteins (consNtuNve and heat-‐inducible HSP).
DefiniNon: any protein (HSP being the largest group), which interacts, stabilizes or helps a non-‐naNve protein to acquire its na?ve conforma?on but is not present in the final funcNonal structure
Heat-‐induced HSP up-‐regulaNon (e.g. Hsp70) thus protects cells against the toxicity of subsequent heaNng (thermotolerance) and this correlates with increased refolding capacity.
The diverse HSP families, their members and mutual interacNons ensure funcNonal specificity to maintain the cellular protein homeostasis (proteostasis)
mutant
nascent
Native stress
38
So, the HSP machines may not be enNrely stupid aBer all
Cell Stress and Chaperones: basic concepts -‐ Harm H. Kampinga
sense, specify and direct protein quality control in an intricate network but rather
39
So, the HSP machines may not be enNrely stupid aBer all
Cell Stress and Chaperones: basic concepts -‐ Harm H. Kampinga
sense, specify and direct protein quality control in an intricate network but rather
39
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