MAPKAP1
Description
The MAPKAP1 (MAPK associated protein 1) is a protein-coding gene located on chromosome 9.
MAPKAP1 is a protein encoded by the MAPKAP1 gene in humans. It is a subunit of mTOR complex 2 (mTORC2) and is highly similar to the yeast SIN1 protein, a stress-activated protein kinase. There are multiple transcript variants of this gene, which encode distinct isoforms. Alternative polyadenylation sites and alternate 3' UTRs have been identified for transcripts of this gene.
MAPKAP1 is a subunit of mTORC2, a protein complex that regulates cell growth and survival in response to hormonal signals. mTORC2 is activated by growth factors and is not sensitive to nutrient levels. It functions upstream of Rho GTPases to regulate the actin cytoskeleton, likely by activating Rho-type guanine nucleotide exchange factors. mTORC2 promotes the formation of stress fibers (F-actin) in response to serum. It plays a critical role in the phosphorylation of AKT1 at Ser-473, which facilitates the phosphorylation of the activation loop of AKT1 at Thr-308 by PDK1, a necessary step for full AKT1 activation. mTORC2 also regulates the phosphorylation of SGK1 at Ser-422 and modulates the phosphorylation of PRKCA at Ser-657. Within mTORC2, MAPKAP1 is essential for complex formation and mTORC2 kinase activity. MAPKAP1 inhibits MAP3K2 by preventing its dimerization and autophosphorylation. It also inhibits HRAS and KRAS signaling. MAPKAP1 enhances osmotic stress-induced phosphorylation of ATF2 and ATF2-mediated transcription. MAPKAP1 is involved in ciliogenesis and regulates cilia length through its interaction with CCDC28B, independent of the mTORC2 complex.
MAPKAP1 is also known as JC310, MIP1, SIN1, SIN1b, SIN1g.
