beta-1-syntrophin; 59 kD dystrophin-associated protein A1 basic component 1; DAPA1B; Tax interaction protein 43; TIP-43; syntrophin-2; BSYN2 (SNTB1, SNT2B1)

Function

• adapter protein that binds to & probably organizes the subcellular localization of a variety of membrane proteins
• may link various receptors to the actin cytoskeleton & the dystrophin glycoprotein complex
• phosphorylated by CaM-kinase 2 (putative)
• interacts with other members of the syntrophin family SNTA1 & SNTB2; with Na+ channel proteins SCN4A & SCN5A (putative).
• interacts with dystrophin protein DMD & related proteins DTNA & UTRN

Structure

• monomer & homodimer (probable)
• the 1st PH domain mediates oligomerization (Ca+2 dependent) (putative)
• the PDZ domain binds to the last 3 or 4 amino acids of ion channels & receptor proteins; association with dystrophin or related proteins probably leaves the PDZ domain available to recruit proteins to the membrane
• the SU domain binds calmodulin (Ca+2-dependent) (putative)
• belongs to the syntrophin family
• contains 1 PDZ domain (DHR domain)
• contains 2 PH domains
• contains 1 SU domain (syntrophin unique)

Compartment

• cell membrane, sarcolemma
• peripheral membrane protein; cytoplasmic side (putative)
• cell junction (putative)
• cytoplasm, cytoskeleton
• in skeletal muscle, it localizes at the cytoplasmic side of the sarcolemmal membrane & at neuromuscular junctions

Alternative splicing

named isoforms=2

Expression

ubiquitous

Pathology

• interacts with the viral HTLV-1 TAX protein

More general terms

• syntrophin (dystrophin-associated protein)
• phosphoprotein

Database

• Entrez gene: http://www.ncbi.nlm.nih.gov/sites/entrez?db=gene&cmd=Retrieve&dopt=Graphics&list_uids=6641
• Kegg: http://www.genome.jp/dbget-bin/www_bget?hsa:6641
• OMIM: https://mirror.omim.org/entry/600026
• UniProt: http://www.uniprot.org/uniprot/Q13884.html