Format

Send to

Choose Destination
See comment in PubMed Commons below
Proc Natl Acad Sci U S A. 2001 Oct 23;98(22):12462-7. Epub 2001 Oct 16.

Oligomerization of the integrin alphaIIbbeta3: roles of the transmembrane and cytoplasmic domains.

Author information

1
Department of Biochemistry and Biophysics and Hematology-Oncology Division, University of Pennsylvania School of Medicine, Philadelphia, PA 19104, USA.

Abstract

Integrins are a family of alpha/beta heterodimeric membrane proteins, which mediate cell-cell and cell-matrix interactions. The molecular mechanisms by which integrins are activated and cluster are currently poorly understood. One hypothesis posits that the cytoplasmic tails of the alpha and beta subunits interact strongly with one another in a 1:1 interaction, and that this interaction is modulated in the course of the activation of alphaIIbbeta3 [Hughes, P. E., et al. (1996) J. Biol. Chem. 271, 6571-6574]. To examine the structural basis for this interaction, protein fragments encompassing the transmembrane helix plus cytoplasmic tails of the alpha and beta subunits of alphaIIbbeta3 were expressed and studied in phospholipid micelles at physiological salt concentrations. Analyses of these fragments by analytical ultracentrifugation, NMR, circular dichroism, and electrophoresis indicated that they had very little or no tendency to interact with one another. Instead, they formed homomeric interactions, with the alpha- and beta-fragments forming dimers and trimers, respectively. Thus, these regions of the protein structure may contribute to the clustering of integrins that accompanies cellular adhesion.

PMID:
11606749
PMCID:
PMC60076
DOI:
10.1073/pnas.221463098
[Indexed for MEDLINE]
Free PMC Article
PubMed Commons home

PubMed Commons

0 comments
How to join PubMed Commons

    Supplemental Content

    Full text links

    Icon for HighWire Icon for PubMed Central
    Loading ...
    Support Center