TPM2

This gene encodes beta-tropomyosin, a member of the actin filament binding protein family, and mainly expressed in slow, type 1 muscle fibers. Mutations in this gene can alter the expression of other sarcomeric tropomyosin proteins, and cause cap disease, nemaline myopathy and distal arthrogryposis syndromes. Alternatively spliced transcript variants encoding different isoforms have been found for this gene

Full Name

tropomyosin 2 (beta)

Function

Binds to actin filaments in muscle and non-muscle cells. Plays a central role, in association with the troponin complex, in the calcium dependent regulation of vertebrate striated muscle contraction. Smooth muscle contraction is regulated by interaction with caldesmon. In non-muscle cells is implicated in stabilizing cytoskeleton actin filaments. The non-muscle isoform may have a role in agonist-mediated receptor internalization.

Biological Process

Biological Process actin filament organization Source:GO_Central1 Publication
Biological Process muscle contraction Source:GO_Central1 Publication
Biological Process regulation of ATP-dependent activity Source:UniProtKB1 Publication

Cellular Location

Cytoplasm, cytoskeleton
Associates with F-actin stress fibers.

Involvement in disease

Nemaline myopathy 4 (NEM4):
A form of nemaline myopathy. Nemaline myopathies are muscular disorders characterized by muscle weakness of varying severity and onset, and abnormal thread-like or rod-shaped structures in muscle fibers on histologic examination. Nemaline myopathy type 4 presents from infancy to childhood with hypotonia and moderate-to-severe proximal weakness with minimal or no progression. Major motor milestones are delayed but independent ambulation is usually achieved, although a wheelchair may be needed in later life.
Arthrogryposis, distal, 1A (DA1A):
A form of distal arthrogryposis, a disease characterized by congenital joint contractures that mainly involve two or more distal parts of the limbs, in the absence of a primary neurological or muscle disease. Distal arthrogryposis type 1 is characterized largely by camptodactyly and clubfoot. Hypoplasia and/or absence of some interphalangeal creases is common. The shoulders and hips are less frequently affected.
Cap myopathy 2 (CAPM2):
A rare congenital skeletal muscle disorder characterized by the presence of cap-like structures which are well demarcated and peripherally located under the sarcolemma and show abnormal accumulation of sarcomeric proteins. Clinical features are early onset of hypotonia and non-progressive or slowly progressive muscle weakness. Respiratory problems are common.
Arthrogryposis, distal, 2B4 (DA2B4):
A form of distal arthrogryposis, a disease characterized by congenital joint contractures that mainly involve two or more distal parts of the limbs, in the absence of a primary neurological or muscle disease. Distal arthrogryposis type 2 is characterized by contractures of the hands and feet, and a distinctive face characterized by prominent nasolabial folds, small mouth and downslanting palpebral fissures.

PTM

Phosphorylated on Ser-61 by PIK3CG. Phosphorylation on Ser-61 is required for ADRB2 internalization (By similarity).