What are myosin heavy chains?
Myosin heavy chain (MHC) is the motor protein of muscle thick filaments. Most organisms produce many muscle MHC isoforms with temporally and spatially regulated expression patterns. This suggests that isoforms of MHC have different characteristics necessary for defining specific muscle properties.
What is myosin heavy chain 1?
Myosin heavy chains (MYHCs) are ubiquitous actin-based motor proteins that convert the chemical energy derived from hydrolysis of ATP into mechanical force that drives diverse motile processes, including cytokinesis, vesicular transport, and cellular locomotion, in eukaryotic cells.
How many heavy chains does myosin have?
two myosin-II heavy chains
The myosin-II molecule is a hexamer composed of two myosin-II heavy chains (MHC-II), two essential light chains (ELCs) that stabilize the neck domain and two regulatory light chains (RLCs) that stabilize the neck and regulate motor activity. This hexameric molecule is generally referred to as the myosin-II monomer.
What is the function of myosin light chains?
Myosin light chain kinase (MLCK) plays a central role in regulating the actin-myosin interaction of smooth muscle. MLCK phosphorylates the light chain of myosin in the presence of Ca2+ and calmodulin (CaM) thereby activating myosin so that it can interact with actin.
What do myosin light chains do?
Myosin light chains are required for the structural integrity of the myosin holoenzyme. In addition, they can have regulatory functions on the mechanoenzymatic activity of the protein complex.
How many polypeptide chains are there in myosin?
four polypeptide chains
A myosin-II molecule consists of four polypeptide chains – two heavy chains and four light chains.
What are thick and thin filaments?
The thin filaments contain actin, tropomyosin, troponins C, I, and T and nebulin. The thick filaments are composed of myosin with the globular heads forming cross-bridges with thin filaments. Myosin-binding proteins, including MyBP-C, are associated with the thick filaments.