Cellular Microenvironments

Better Signaling Through Glycoproteins

Science's STKE  22 Jan 2002:
Vol. 2002, Issue 116, pp. tw40
DOI: 10.1126/stke.2002.116.tw40

The term "immunological synapse" refers to the areas of contact between two or more closely apposed immune cells. These contact points have a high concentration of signaling and adhesion-promoting proteins that are tethered within discrete lipid rafts located on plasma membranes. Hakomori summarizes existing data and hypothesizes the existence and biological function of glycosynapses--clusters of glycosylated proteins that mediate adhesion and signaling--on the surface of cells that can alter signaling and adhesion, leading to changes in cell phenotype. Three types of glycosynapses may exist: (i) glycosphingolipid clusters that contain signaling proteins and are involved in cell adhesion and signal transduction; (ii) O-linked mucin-bearing clusters with signaling proteins all contained within cholesterol-rich domains; and (iii) clusters of N-glycosylated adhesion receptor proteins with tetraspanins and gangliosides. The author discusses the different biological effects that each of these glycosynapse types might have on cell physiology and morphology during development and differentiation.

S-i. Hakomori, The glycosynapse. Proc. Natl. Acad. Sci. U.S.A. 99, 225-232 (2002). [Abstract] [Full Text]