Overview:

QIK is a serine/threonine protein kinase that contains an N-terminal kinase domain, a central domain with ubiquitin-associate motif, and a C-terminal PKA phosphorylation site. QIK can phosphorylate IRS1 and overexpression of QIK in adipocyte elevates the phosphorylation of IRS1 (1). The QIK-mediated phosphorylation of IRS1 may modulate the efficiency of insulin signal transduction and could be responsible for insulin resistance associated with diabetes (1). Insulin disrupts TORC2 activity by induction of QIK which then stimulates the phosphorylation and cytoplasmic translocation of TORC2. Phosphorylated TORC2 is subsequently degraded by the 26S proteasome (2).

References:

1. Horike N, et al: Adipose-specific expression, phosphorylation of ser794 in insulin receptor substrate-1, and activation in diabetic animals of salt-inducible kinase-2. J. Biol. Chem. 278: 18440-18447, 2003.

2. Dentin R, et al: Insulin modulates gluconeogenesis by inhibition of the coactivator TORC2. Nature 449: 366-369, 2007.