Syntrophin Beta 2

From Anvita Health Wiki

Contents 1 Function 2 Structure 3 Compartment 4 Alternative-splicing 5 Expression 6 Notes 7 More General Terms 8 Internet Database 9 References

Function

• adapter protein
• 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
• may play a role in regulation of secretory granules via its interaction with PTPRN
• phosphorylated; partially dephosphorylated upon insulin stimulation
• interacts with other members of the syntrophin family: SNTA1 & SNTB1; & with the Na+ channel proteins SCN4A & SCN5A
• interacts with SAST, MAST205, microtubules & microtubule-associated proteins
• interacts with the dystrophin protein DMD & related proteins DTNA & UTRN, & with the neuroregulin receptor ERBB4
• interacts with PTPRN when phosphorylated, protecting PTPRN from protein cleavage by CAPN1
• dephosphorylation upon insulin stimulation disrupts interaction with PTPRN & results in cleavage of PTPRN

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 ( putative)
• 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

• membrane, cytoplasmic vesicle, secretory vesicle membrane
• peripheral membrane protein
• cell junction
• cytoplasm, cytoskeleton
• in muscle, localized at the neuromuscular junction
• in insulinoma cell line, it is enriched in secretory granules

Alternative-splicing

• named isoforms=2

Expression

• ubiquitous
• isoform 1 is the predominant isoform
• isoform 2 is highly expressed in liver & heart
• low expression of isoform 2 in all other tissues

Notes

• one isoform may lack domains required for interaction with dystrophin related proteins
• one isoforma may be produced at very low levels due to a premature stop codon in the mRNA, leading to nonsense-mediated mRNA decay

More General Terms

• syntrophin (dystrophin-associated protein)
• phosphoprotein

Internet Database

Entrez gene: 6645
Kegg: [1]
OMIM: 600027
Prosite: [2]
Prosite: [3]
UniProt: [4]

References

1. OMIM [5]
2. Entrez Gene [6]
3. UniProt [7]

beta-2-syntrophin; 59 kD dystrophin-associated protein A1 basic component 2; syntrophin-3; SNT3; syntrophin-like; SNTL (SNTB2 D16S2531E SNT2B2 SNTL)