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Static Adhesion Assay for the Study of Integrin Activation in T Lymphocytes
09:14

Static Adhesion Assay for the Study of Integrin Activation in T Lymphocytes

Published on: June 13, 2014

The cell adhesion molecule CD31 is phosphorylated after cell activation. Down-regulation of CD31 in activated T

J L Zehnder1, K Hirai, M Shatsky

  • 1Division of Hematology, Stanford University School of Medicine, California 94305-5112.

The Journal of Biological Chemistry
|March 15, 1992
PubMed

Insights

Researchers cloned CD31, a cell adhesion molecule found on various blood and endothelial cells. CD31 expression decreases after T cell activation, and its phosphorylation involves protein kinase C, potentially affecting cell adhesion and immune responses.

Area of Science:

  • Immunology
  • Molecular Biology
  • Cell Biology

Background:

  • CD31 (also known as PECAM-1) is a cell adhesion molecule belonging to the immunoglobulin superfamily.
  • It is expressed on various cell types, including platelets, leukocytes (granulocytes, monocytes, lymphocytes), and endothelial cells.

Purpose of the Study:

  • To report the independent cloning of the cDNA for CD31.
  • To investigate the regulation of CD31 expression and its post-translational modification upon cell activation.

Main Methods:

  • Northern blot analysis to detect mRNA transcripts.
  • Immunoblotting to assess protein expression.
  • Nuclear run-on assays to study transcription rates.
  • Cell activation studies followed by phosphorylation analysis.

Main Results:

  • CD31 cDNA was successfully cloned.
  • Northern analysis revealed distinct mRNA transcripts in different cell lines, with an additional transcript in endothelial cells.
  • T cell activation led to down-regulation of CD31 mRNA and protein expression, partly due to decreased transcription.
  • CD31 undergoes rapid phosphorylation on serine and/or threonine residues, mediated by protein kinase C, upon cell activation.

Conclusions:

  • CD31 phosphorylation may modulate its function in cellular adhesion.
  • Down-regulation of CD31 expression following activation could influence immune cell targeting and localization to inflammatory sites.

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