Beta dystrobrevin also known as DTNB is a protein

Protein

Proteins are biochemical compounds consisting of one or more polypeptides typically folded into a globular or fibrous form, facilitating a biological function. A polypeptide is a single linear polymer chain of amino acids bonded together by peptide bonds between the carboxyl and amino groups of...

 which in humans is encoded by the DTNB gene

Gene

A gene is a molecular unit of heredity of a living organism. It is a name given to some stretches of DNA and RNA that code for a type of protein or for an RNA chain that has a function in the organism. Living beings depend on genes, as they specify all proteins and functional RNA chains...

.

Function

This gene encodes dystrobrevin beta, a component of the dystrophin

Dystrophin

Dystrophin is a rod-shaped cytoplasmic protein, and a vital part of a protein complex that connects the cytoskeleton of a muscle fiber to the surrounding extracellular matrix through the cell membrane. This complex is variously known as the costamere or the dystrophin-associated protein complex...

-associated protein complex (DPC

Costamere

The costamere is a structural-functional component of striated muscle cells which connects the sarcomere of the muscle to the cell membrane.Costameres are sub-sarcolemmal protein assemblies circumferentially aligned in register with the Z-disk of peripheral myofibrils...

). The DPC consists of dystrophin and several integral and peripheral membrane proteins, including dystroglycan

Dystroglycan

Dystroglycan is a protein that in humans is encoded by the DAG1 gene.Dystroglycan is one of the dystrophin-associated glycoproteins, which is encoded by a 5.5 kb transcript in Homo sapiens by chromosome 3. There are two exons that are separated by a large intron...

s, sarcoglycan

Sarcoglycan

The sarcoglycans are a family of transmembrane proteins involved in the protein complex responsible for connecting the muscle fibre cytoskeleton to the extracellular matrix, preventing damage to the muscle fibre sarcolemma through shearing forces.The dystrophin glycoprotein complex is a...

s, syntrophin

Syntrophin

The syntrophins are a family of five 60-kiloDalton proteins that are associated with dystrophin, the protein associated with Duchenne muscular dystrophy and Becker muscular dystrophy. The name comes from the Greek word syntrophos, meaning "companion." The five syntrophins are encoded by separate...

s and dystrobrevin

Dystrobrevin

Dystrobrevin is a protein that binds to dystrophin in the costamere of skeletal muscle cells. There are at least two isoforms of dystrobrevin in man, α-dystrobrevin and β-dystrobrevin....

 alpha and beta. The DPC localizes to the sarcolemma and its disruption is associated with various forms of muscular dystrophy. Dystrobrevin beta is thought to interact with syntrophin and the DP71 short form of dystrophin. Alternatively spliced

Alternative splicing

Alternative splicing is a process by which the exons of the RNA produced by transcription of a gene are reconnected in multiple ways during RNA splicing...

transcript variants encoding different isoforms have been identified.