Tyrosine phosphorylation of the dense plaque protein paxillin is regulated during smooth muscle contraction

Research output: Contribution to journalArticle

49 Scopus citations

Abstract

Regulation of the attachment of actin filaments to the cell membrane at membrane-associated dense plaque (MADP) sites could allow smooth muscle cells to modulate their cytostructure in response to changes in external stress. In this study, changes in the tyrosine phosphorylation of the MADP protein paxillin were measured by Western blot during the contraction and relaxation of tracheal smooth muscle strips. Tyrosine phosphorylation of paxillin increased by three- to fourfold with a time course similar to force development during contractile stimulation with acetylcholine (ACh), 5- hydroxytryptamine, and KCl and decreased during washout of contractile stimuli and during relaxation induced by forskolin. Immunoprecipitation of muscle extracts with multiple rounds of anti-phosphotyrosine antibody removed ~20% of the total paxillin in resting muscles and ~60% of paxillin in muscles maximally stimulated with ACh. These results provide the first evidence associating the tyrosine phosphorylation of paxillin with the active contraction of smooth muscle or with any functional response of a fully differentiated tissue in vivo. The results are consistent with a role for MADP proteins in the regulation of force development in smooth muscle.

Original languageEnglish (US)
Pages (from-to)C1594-C1602
JournalAmerican Journal of Physiology - Cell Physiology
Volume271
Issue number5 40-5
DOIs
StatePublished - Nov 1996

Keywords

  • cytoskeleton
  • focal adhesion protein
  • membrane-associated dense plaque

ASJC Scopus subject areas

  • Clinical Biochemistry
  • Cell Biology
  • Physiology
  • Physiology (medical)

Fingerprint Dive into the research topics of 'Tyrosine phosphorylation of the dense plaque protein paxillin is regulated during smooth muscle contraction'. Together they form a unique fingerprint.

  • Cite this