Background
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
