Chapter all: Cell Junctions
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BIO120H1 Full Course Notes
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Document Summary
Cell junctions and the extracellular matrix: direct and extracellular matrix interactions are social interactions between cells and hold cells together. The matrix that bears most of the mechanical stress the tissue is subjected to, not the individual cells. Direct attachments between cells are rare, but cells are attached to the matrix. There are two protein superfamilies, corresponding to two kinds of external attachments: cadherin superfamily chiefly mediate attachment of cell to cell. Integrin superfamily chiefly mediate attachment of cells to matrix. Removing ca will cause adhesions to break up (thus ca2+ mediated): classical and nonclassical cahejrins make up the cadherin superfamily, classical cadherins are closely related in sequence throughout their extracellular and intracellular domains. 3 first cahedrin types to be discovered: e- epithelial cells, n - nerve cells, p - placenta and epidermis. Individual cadehrins bond weakly, but there are many of them velcro principle .
