CELL TO CELL JUNCTIONS BY: ASHLEY COHN
SURFACE MARKERS STRUCTURE
VARIABLE,
INTEGRAL OR GLYCOLIPIDS
IN PLASMA MEMBRANE.
FUNCTION IDENTIFY THE
CELL
EXAMPLE MHC
COMPLEXES, BLOOD GROUPS,
ANTIBODIES
SEPTATE JUNCTIONS/ TIGHT JUNCTIONS
STRUCTURE TIGHTLY BONDED,
LEAK PROOF, FIBROUS CLAUDIN
PROTEIN THAT SEALS THE CELL
FUNCTION HOLDS CELL
TOGETHER SO THAT MATERIALS PASS THROUGH
BUT NOT BETWEEN THE CELLS
EXAMPLE JUNCTIONS BETWEEN
EPITHELIAL CELLS IN THE
GUT
ADHESIVE JUNCTION(DESMOSOME)
STRUCTURE VARIENT CADHERINS,
DESMOCOLLINS, BIND TO
INTERMEDIATE FILAMENTS OF
CYTOSKELETON
FUNCTION CREATES STRONG
FLEXIBLE CONNECTIONS
BETWEEN CELLS, FOUND IN
VERTEBRATES
EXAMPLE EPITHELIUM
• CADHERIN IS A PROTEIN WHICH IS A CA2+
DEPENDENT ADHESION MOLECULE WITH VERY WIDE POLYGENETIC DISTRIBUTION.
• DESMOSOMES ARE A CADHERIN BASED JUNCTION UNIQUE TO VERTEBRATES. THEY CONTAIN THE CADHERIN'S DESMOCOLLIN.
ADHESIVE JUNCTION ( ADHERENS JUNCTION)
STRUCTURE CLASSIC
ADHERINS BIND TO
MICROFILAMENTS OF
CYTOSKELETONS
FUNCTIONCONNECTS CELLS
TOGETHER, OLDEST FORM OF JUNCTION,
FOUND IN ALL MULTICELLULAR
ORGANISMS
EXAMPLE TISSUE WITH
HIGH MECHANICAL
STRESS SUCH AS THE SKIN
ADHESIVE JUNCTION(HEMIDESMOSOMES, FOCAL ADHESION)
STRUCTURE INTEGRIN
PROTEINS BINDS CELL TO
EXTRACELLULAR MATRIX
FUNCTION PROVIDE
ATTACHMENT TO A SUBSTRATE
EXAMPLE INVOLVED IN
CELL MOVEMENT AND IMPORTANT
DURING DEVELOPMENT
COMMUNICATING JUNCTION (GAP JUNCTION )
STRUCTURE SIX TRANSMEMBRANE
CONNEXON /PANNEXIN PROTEINS
CREATING A PORE THAT CONNECTS
CELLS
FUNCTION ALLOWS FOR PASSAGE OF
SMALL MOLECULES FROM CELLS TO
CELL IN A TISSUE
EXAMPLE EXCITABLE
TISSUE SUCH AS HEART MUSCLE
•PANNEXINS ARE PROTEIN FOUND IN INVERTEBRATES
•CONNEXONS ARE A PROTEIN IN VERTEBRATES
COMMUNICATING JUNCTION ( PLASMODESMATA)
STRUCTURE CYTOPLASMIC CONNECTIONS
BETWEEN GAPS IN CONJOINING PLANTS CELL
WALLS
FUNCTION COMMUNICATING
JUNCTIONS BETWEEN PLANT
CELLS
EXAMPLE PLANT TISSUE
•PLASMODESMATA IS CYTOPLASMIC CONNECTIONS THAT FORM ACROSS THE TOUCHING PLASMA MEMBRANES
ALL INFORMATION IN THIS POWER POINT CAN BE FOUND IN MGRAW HILL BIOLOGY 10TH
EDITION ON PAGES 83-85