Tyrosine phosphorylation of paxillin may be involved in vascular smooth muscle contraction.
- Author:
Lian Hua FANG
1
;
Kyoung Soo CHO
;
Sang Jin LEE
;
Hee Yul AHN
Author Information
1. Department of Pharmacology, College of Medicine, Chungbuk National University, Chongju, Korea.
- Publication Type:Original Article
- Keywords:
Paxillin;
Phosphorylation;
Tyrosine kinase;
Vascular smooth muscle contraction
- MeSH:
Actin Cytoskeleton;
Animals;
Cell Membrane;
Cytoskeletal Proteins;
Muscle, Smooth;
Muscle, Smooth, Vascular*;
Norepinephrine;
Paxillin*;
Phosphorylation*;
Protein-Tyrosine Kinases;
Rats;
Tyrosine*
- From:The Korean Journal of Physiology and Pharmacology
2000;4(3):211-217
- CountryRepublic of Korea
- Language:English
-
Abstract:
Paxillin is a regulatory component of the complex of cytoskeletal proteins that link the actin cytoskeleton to the plasma membrane. However, the role of paxillin during smooth muscle contraction is unclear. We investigated a possible role for the membrane-associated dense plaque protein paxillin in the regulation of contraction in rat aortic vascular smooth muscle. The tyrosine phosphorylation of paxillin, which was increased by norepinephrine, reached a peak level after 1 min stimulation and then decreased with time. However, norepinephrine induced a sustained contraction that reached a steady state 30 min after application. Pretreatment with tyrphostin, an inhibitor of tyrosine kinase, inhibited the tyrosine phosphorylation of paxillin and also the contraction stimulated by norepinephrine. Both inhibitions were concentration-dependent, and the degree of correlation between them was high. These results show that, in rat aortic smooth muscle, tyrosine kinase(s) activated by norepinephrine may phosphorylate the tyrosine residues of paxillin, thereby providing a source of regulation during vascular smooth muscle contraction.
