TBC1D4

Also known as AS160, NIDDM5, TBC1 domain family member 4

AS160 (Akt substrate of 160 kDa), which was originally known as TBC1 domain family member 4 (TBC1D4), is a Rab GTPase-activating protein that in humans is encoded by the TBC1D4 gene.

Gene data

TBC1D4

Name: TBC1 domain family member 4
Type: protein-coding
Aliases: AS160, NIDDM5

This gene is a member of the Tre-2/BUB2/CDC16 domain family. The protein encoded by this gene is a Rab-GTPase-activating protein, and contains two phopshotyrosine-binding domains (PTB1 and PTB2), a calmodulin-binding domain (CBD), a Rab-GTPase domain, and multiple AKT phosphomotifs. This protein is thought to play an important role in glucose homeostasis by regulating the insulin-dependent trafficking of the glucose transporter 4 (GLUT4), important for removing glucose from the bloodstream into skeletal muscle and fat tissues. Reduced expression of this gene results in an increase in GLUT4 levels at the plasma membrane, suggesting that this protein is important in intracellular retention of GLUT4 under basal conditions. When exposed to insulin, this protein is phosphorylated, dissociates from GLUT4 vesicles, resulting in increased GLUT4 at the cell surface, and enhanced glucose transport. Phosphorylation of this protein by AKT is required for proper translocation of GLUT4 to the cell surface. Individuals homozygous for a mutation in this gene are at higher risk for type 2 diabetes and have higher levels of circulating glucose and insulin levels after glucose ingestion. Alternative splicing results in multiple transcript variants encoding different isoforms. [provided by RefSeq, Aug 2015].

via MyGene.info

Gene · Ensembl

TBC1 domain family member 4

Symbol: TBC1D4
Biotype: Protein coding
Organism: Homo sapiens
Location: 13:75,283,488-75,482,660
Strand: Reverse (−)
Assembly: GRCh38

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via Ensembl · EMBL-EBI

Wikidata facts

Show 5 more facts

HomoloGene ID: 45451
exact match: identifiers.org/ncbigene/9882
genomic start: 75283503
genomic end: 75482169
cytogenetic location: 13q22.2

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Contents

Isoforms
Pathogenic mutations
References
Further reading

AS160 (Akt substrate of 160 kDa), which was originally known as TBC1 domain family member 4 (TBC1D4), is a Rab GTPase-activating protein that in humans is encoded by the TBC1D4 gene.

The 160 kD protein product was first discovered in a screen for novel substrates of the serine-threonine kinase Akt2, which phosphorylates AS160 at Thr-642 and Ser-588 after insulin stimulation. Insulin stimulation of fat and muscle cells results in translocation of the glucose transporter GLUT4 to the plasma membrane, and this translocation process is dependent on phosphorylation of AS160. The role of AS160 in GLUT4 translocation is mediated by its GTPase activating domain and interactions with Rab proteins in vesicle formation, increasing GLUT4 translocation when its GTPase activity is inhibited by Akt phosphorylation. Specifically, this inhibition activates RAB2A, RAB8A, RAB10 and RAB14.