The complex of proteins that form the contractile mechanism of skeletal muscle include:
myosin
tropomysin
troponin, with three subunits, troponin I, troponin T and troponin C
vinculin functions in the alignment of sarcomeric myofibrils. Focal staining is seen in rhabdomyoblasts and diffuse staining in small poorly differentiated cells of embryonal rhabdomyosarcoma. Immunoreactivity has been observed in leiomyosarcomas.
Diagnostic utility
Other than actins, low sensitivity limits the value of all of these proteins as markers of skeletal muscle differentiation.
Diagnostic Immunohistochemistry edited by Professor D. J. Dabbs, pages 69
This page last revised 4.6.2001.
©SMUHT/PW Bishop