MYOSIN HEAVY-CHAIN ISOFORMS IN SMOOTH-MUSCLE

In recent years, significant progress has been made toward understandi ng smooth muscle myosin heavy chain (SMHC) structure. Molecular clonin g analysis has identified four different MHC isoforms. They are produc ts of a single gene and result from alternative mRNA splicing. In addi tion, two non-muscle MHC isoforms are also expressed in smooth muscle cells. Studies show that SMHC expression is highly tissue specific and does not appear in cardiac or skeletal muscle cells. Each smooth musc le tissue is characterized by a specific pattern of MHC isoform expres sion that changes during development and disease. This review essentia lly focuses on SMHC isoforms and their expression in mammals. (C) 1997 Elsevier Science Inc.