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integrin

Function: - cell surface receptors - interact with the extracellular matrix - role in attachment to other cells - mediate intracellular signals - role in cell shape, mobility, cell cycle - bidirectional signalling [5] a) extracellular to intracellular signalling b) intracellular to extracellular signalling Structure: - composed of alpha & beta subunits selected from 16 alpha & 8 beta subunits that heterodimerize to produce more than 20 different receptors [3] - the short cytoplasmic domains of the alpha & beta subunits do not have intrinsic enzyme activity, but appear to function by nucleating large complexes of cytoskeletal proteins & cytoskeletal-associated protein kinases - integrin beta-4 is the exception, with a cytoplasmic domain in excess of 1000 residues - integrin-alpha(s) contain highly divergent amino acid sequences, whereas the integrin-beta subunits show partial sequence conservation - the integrin-beta(s) target integrins to focal adhesions in a ligand-independent manner, whereas the integrin-alpha(s) regulate the specificity of ligand-dependent interactions

Interactions

molecular events

Specific

CD49 or Very Late Antigen (VLA) glycoprotein IIB/IIIA integrin alpha-10/beta-1 integrin alpha-11/beta-1 integrin alpha-2b/beta-3 integrin alpha-4/beta-7 integrin alpha-6/beta-4 integrin alpha-7/beta-1 integrin alpha-8/beta-1 integrin alpha-9/beta-1 integrin alpha-D/beta-2 (CD11d/CD18) integrin alpha-E/beta-7 integrin alpha-M/beta-2 (CD11b/CD18, MAC1) integrin alpha-V/beta-3 integrin alpha-V/beta-5 integrin alpha-V/beta-6 integrin alpha-V/beta-8 integrin alpha-X/beta-2 (CD11c/CD18) lymphocyte function-associated antigen-1 (LFA-1, leukocyte adhesion protein LFA-1, integrin alpha-L/beta-2, CD11a/CD18) vitronectin receptor

General

adhesion receptor immunoglobulin superfamily protein multisubunit protein

Properties

COMPARTMENT: plasma membrane MOTIF: focal adhesion site transmembrane domain SUBUNITS: integrin-alpha MOTIF: cysteine residue {CYS1} MODIFICATION: cysteine residue {CYS2} cysteine residue {CYS2} MODIFICATION: cysteine residue {CYS1} transmembrane domain kxgffkr NAME: kxgffkr SITE: cytoplasmic domain FOR-BINDING-OF: calreticulin FORM: kxgffkr integrin-beta MOTIF: binding site FOR-BINDING-OF: RGD cell-attachment sequence cysteine-rich region transmembrane domain binding site SITE: C-TERMINAL FOR-BINDING-OF: cytoskeletal protein

References

  1. Springer TA. Adhesion receptors of the immune system. Nature. 1990 Aug 2;346(6283):425-34. Review. PMID: 1974032
  2. Molecular Cell Biology (2nd ed) Darnell J; Lodish H & Baltimore D (eds), Scientific American Books, WH Freeman, NY 1990, pg 921
  3. Clark EA & Brugge JS Integrins and signal transduction pathways: the road taken. Science 268:233 1995 PMID: 7716514
  4. Humphries MJf Integrin structure Biochem Soc Trans 2000, 28:311 PMID: 10961914
  5. Hynes R Integrins: bidirectional, allosteric signaling machines Cell 2002, 110:683 PMID: 12297042
  6. Wikipedia; Note: Integrin entry http://en.wikipedia.org/wiki/integrin

Component-of

adheron

Components

integrin-alpha integrin-beta