TPM3

This gene encodes a member of the tropomyosin family of actin-binding proteins involved in the contractile system of striated and smooth muscles and the cytoskeleton of non-muscle cells. Tropomyosins are dimers of coiled-coil proteins that polymerize end-to-end along the major groove in most actin filaments. They provide stability to the filaments and regulate access of other actin-binding proteins. In muscle cells, they regulate muscle contraction by controlling the binding of myosin heads to the actin filament. Mutations in this gene result in autosomal dominant nemaline myopathy, and oncogenes formed by chromosomal translocations involving this locus are associated with cancer. Multiple transcript variants encoding different isoforms have been found for this gene. [provided by RefSeq]

TPM3

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.

Biological Process actin filament organization Source:GO_Central1 Publication
Biological Process muscle contraction Source:GO_Central1 Publication

Cytoplasm, cytoskeleton

Nemaline myopathy 1 (NEM1):
A form of nemaline myopathy with autosomal dominant or recessive inheritance. Nemaline myopathies are disorders characterized by muscle weakness of varying onset and severity, and abnormal thread-like or rod-shaped structures in muscle fibers on histologic examination. Autosomal dominant NEM1 is characterized by a moderate phenotype with onset between birth and early second decade of life. Weakness is diffuse and symmetric with slow progression often with need for a wheelchair in adulthood. The autosomal recessive form has onset at birth with moderate to severe hypotonia and diffuse weakness. In the most severe cases, death can occur before 2 years. Less severe cases have delayed major motor milestones, and these patients may walk, but often need a wheelchair before 10 years.
Myopathy, congenital, with fiber-type disproportion (CFTD):
A genetically heterogeneous disorder in which there is relative hypotrophy of type 1 muscle fibers compared to type 2 fibers on skeletal muscle biopsy. However, these findings are not specific and can be found in many different myopathic and neuropathic conditions.
Cap myopathy 1 (CAPM1):
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 slowly progressive muscle weakness. Respiratory problems are common.