MYL2

Thus gene encodes the regulatory light chain associated with cardiac myosin beta (or slow) heavy chain. Ca+ triggers the phosphorylation of regulatory light chain that in turn triggers contraction. Mutations in this gene are associated with mid-left ventricular chamber type hypertrophic cardiomyopathy. [provided by RefSeq, Jul 2008]

Full Name

Myosin Light Chain 2

Function

Contractile protein that plays a role in heart development and function (PubMed:23365102, PubMed:32453731).

Following phosphorylation, plays a role in cross-bridge cycling kinetics and cardiac muscle contraction by increasing myosin lever arm stiffness and promoting myosin head diffusion; as a consequence of the increase in maximum contraction force and calcium sensitivity of contraction force. These events altogether slow down myosin kinetics and prolong duty cycle resulting in accumulated myosins being cooperatively recruited to actin binding sites to sustain thin filament activation as a means to fine-tune myofilament calcium sensitivity to force (By similarity).

During cardiogenesis plays an early role in cardiac contractility by promoting cardiac myofibril assembly (By similarity).

Biological Process

Cardiac muscle contraction Source: GO_Central
Cardiac myofibril assembly Source: BHF-UCL
Heart contraction Source: BHF-UCL
Heart development Source: UniProtKB
Muscle cell fate specification Source: GO_Central
Negative regulation of cell growth Source: BHF-UCL
Positive regulation of the force of heart contraction Source: UniProtKB
Regulation of striated muscle contraction Source: ProtInc
Regulation of the force of heart contraction Source: UniProtKB
Ventricular cardiac muscle tissue morphogenesis Source: BHF-UCL

Cellular Location

A band

Involvement in disease

Cardiomyopathy, familial hypertrophic 10 (CMH10):
A hereditary heart disorder characterized by ventricular hypertrophy, which is usually asymmetric and often involves the interventricular septum. The symptoms include dyspnea, syncope, collapse, palpitations, and chest pain. They can be readily provoked by exercise. The disorder has inter- and intrafamilial variability ranging from benign to malignant forms with high risk of cardiac failure and sudden cardiac death. Rarely, patients present a variant of familial hypertrophic cardiomyopathy, characterized by mid-left ventricular chamber thickening.
Myopathy, myofibrillar, 12, infantile-onset, with cardiomyopathy (MFM12):
A form of myofibrillar myopathy, a group of chronic neuromuscular disorders characterized at ultrastructural level by disintegration of the sarcomeric Z disk and myofibrils, and replacement of the normal myofibrillar markings by small dense granules, or larger hyaline masses, or amorphous material. MFM12 is an autosomal recessive, severe form characterized by progressive myopathy with onset shortly after birth, tremor or clonus at birth, and cardiomyopathy usually leading to death by 6 months of age. Skeletal and cardiac muscle tissues show fiber-type disproportion with small type I and normal sized type II fibers, and myofibrillar disorganization.

PTM

N-terminus is methylated by METTL11A/NTM1.
Phosphorylated by MYLK3 and MYLK2; promotes cardiac muscle contraction and function (By similarity). Dephosphorylated by PPP1CB complexed to PPP1R12B (By similarity). The phosphorylated form in adult is expressed as gradients across the heart from endocardium (low phosphorylation) to epicardium (high phosphorylation); regulates cardiac torsion and workload distribution (By similarity).