KINESIOL 1A03 Lecture Notes - Lecture 4: Adherens Junction, Tight Junction, Intermediate Filament

• School: McMaster University
• Department: Kinesiology
• Course: KINESIOL 1A03
• Professor: Krista Howarth

Document Summary

Cells can be held together in a number of ways. Points of contact between plasma membrane of cells are called cell junctions. Consist of weblike strands of transmembrane proteins that fuse together the outer surfaces of adjacent plasma membranes to seal off passageways between adjacent cells. Help to provide barrier/protection in lining of stomach and urinary bladder. Dense layer of proteins on inside of plasma membrane. Plaque (layer of protein) attaches to microfilaments (of cytoskeleton) Allows adjacent cells to resist separation (ex. Resist tension, prevent cardiac muscle cells from pulling apart during contraction. Plaque doesn"t attach to microfilaments but attaches to intermediate filaments that consist of the protein keratin. Attach plasma membrane to a basement membrane, don"t link adjacent cells. On inside, integrins attach to intermediate filaments made of protein keratin. On outside, integrins attach to protein laminin. Thus, hemidesmosomes anchor cells not to each other but to basement membrane. Allow cells in a tissue to communicate with one another.