How is calmodulin regulated?
Calmodulin-regulated enzymes can be divided into three classes according to their abilities to bind with and to be activated by calmodulin fragments: enzymes which are activated by the C-terminal fragment, such as the Ca2+-ATPase and phosphorylase kinase; enzymes which require both halves of the molecule, such as …
How does calmodulin change the contraction of muscle?
The overall result of this protein-protein interaction is a physiological effect, e.g., Ca2+ binding to calmodulin in smooth muscle allows it to interact with and activate myosin light chain kinase which catalyzes the phosphorylation of myosin. This reaction results in contraction of the smooth muscle.
What is the role of calmodulin in smooth muscle contraction?
The principal function of calmodulin in smooth muscle is to activate crossbridge cycling and the development of force in response to a [Ca2+]i transient via the activation of myosin light-chain kinase and phosphorylation of myosin.
What is the effect of calmodulin?
Calmodulin plays an important role in excitation contraction (EC) coupling and the initiation of the cross-bridge cycling in smooth muscle, ultimately causing smooth muscle contraction. In order to activate contraction of smooth muscle, the head of the myosin light chain must be phosphorylated.
What is the function of calmodulin?
Calmodulin is a ubiquitous, highly conserved protein that plays a critical role in numerous essential cellular functions, including Ca 2+ transport, cell motility, cytoskeletal assembly, protein phosphorylation/dephosphorylation, cell proliferation and cell cycle progression.
Why is calmodulin a cooperative binding protein?
Calcium binding by calmodulin exhibits considerable cooperativity, making calmodulin an unusual example of a monomeric (single-chain) cooperative-binding protein. Furthermore, target binding alters the binding affinity of calmodulin toward Ca 2+ ions, which allows for complex allosteric interplay between Ca 2+ and target binding interactions.
What is the PMID for calmodulin?
PMID 9438870. ^ Yamniuk AP, Vogel HJ (May 2004). “Calmodulin’s flexibility allows for promiscuity in its interactions with target proteins and peptides”. Molecular Biotechnology. 27 (1): 33–57. doi: 10.1385/MB:27:1:33.
What is ubiquitination by sides?
Ubiquitination by SidEs is initiated by means of ADP-ribosylation at R42 of ubiquitin, which is catalysed by mono-ADP ribosyltransferase (mART) 2.