Open AccessExpression of the fast twitch troponin complex, fTnT, fTnI and fTnC, in vascular smooth muscle
Author(s) -
Moran Carlos M.,
Garriock Robert J.,
Miller Melanie K.,
Heimark Ronald L.,
Gregorio Carol C.,
Krieg Paul A.
Publication year - 2008
Publication title -
cell motility and the cytoskeleton
Language(s) - English
Resource type - Journals
eISSN - 1097-0169
pISSN - 0886-1544
DOI - 10.1002/cm.20291
Subject(s) - biology , troponin , vascular smooth muscle , troponin c , actin , myocyte , cardiac muscle , troponin i , troponin complex , skeletal muscle , nebulin , troponin t , anatomy , microbiology and biotechnology , medicine , sarcomere , endocrinology , smooth muscle , titin , myocardial infarction
It is generally believed that proteins of the troponin complex are not expressed in smooth muscle. We have directly assayed for expression of troponin transcripts in mouse vascular smooth muscle and found that troponin sequences normally associated with fast twitch skeletal muscle (fTnT, fTnI, fTnC) were present at significant levels in the thoracic aorta. In situ hybridization experiments demonstrated that fTnT, fTnI and fTnC transcripts were expressed in the smooth muscle layer of mouse blood vessels of all sizes. Protein blot analysis using rat tissue showed that at least two members of the troponin complex, Troponin T and Troponin I, were translated in vascular smooth muscle of the aorta. Finally, immuno‐fluorescence microscopy of rat aortic smooth muscle revealed that TnT and TnI are localized in a unique pattern, coincident with the distribution of tropomyosin. It seems likely therefore, that a complete troponin complex is expressed in vascular smooth muscle and is associated with the contractile machinery of the cell. These observations raise the possibility that troponins play a role in regulation of smooth muscle function. Cell Motil. Cytoskeleton 2008. © 2008 Wiley‐Liss, Inc.