Chapter 5Ligand gated ion channels, intracellular
receptors and phosphorylation cascades
You Must Know
• The function of ligand gated ion channels, intracellular receptors and phosphorylation cascades.
ligand-gated ion channel
Ions
Plasma membrane
Signaling molecule(ligand)
1Gate
closed
Ligand-gated ion channel receptor
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Cellular response
Gateopen
2
Gate closed3
Steroid hormone interacting with an intracellular
receptor
DNA
Plasma membrane
Hormone- receptorcomplex
Receptorprotein
Newprotein
Hormone (testosterone)
mRNA
EXTRA-CELLULAR
FLUID
CYTOPLASM
NUCLEUS
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Hydrophobic
phosphorylation cascade
Receptor
Signaling molecule
Activated relay molecule
Inactiveprotein
kinase 1
Phosphorylation cascade
Inactiveprotein
kinase 2
Activeprotein
kinase 1
Activeprotein
kinase 2
Activeprotein
Inactiveprotein
Cellularresponse
ADP
ADP
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Protein phosphatases
Protein kinase
Figure 5.26
Phosphorylationcascade
Inactivetranscriptionfactor
NUCLEUS
CYTOPLASM
DNA
mRNA
Gene
Activetranscriptionfactor Response
Reception
Transduction
Growth factor
Receptor
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