cd05618: STKc_aPKC_iota (this model, PSSM-Id:88519 is obsolete and has been replaced by 270769)
Catalytic domain of the Protein Serine/Threonine Kinase, Atypical Protein Kinase C iota
Serine/Threonine Kinases (STKs), Atypical Protein Kinase C (aPKC) subfamily, iota isoform, catalytic (c) domain. STKs catalyze the transfer of the gamma-phosphoryl group from ATP to serine/threonine residues on protein substrates. The aPKC subfamily is part of a larger superfamily that includes the catalytic domains of other protein STKs, protein tyrosine kinases, RIO kinases, aminoglycoside phosphotransferase, choline kinase, and phosphoinositide 3-kinase. PKCs are classified into three groups (classical, atypical, and novel) depending on their mode of activation and the structural characteristics of their regulatory domain. aPKCs only require phosphatidylserine (PS) for activation. There are two aPKC isoforms, zeta and iota. PKC-iota is directly implicated in carcinogenesis. It is critical to oncogenic signaling mediated by Ras and Bcr-Abl. The PKC-iota gene is the target of tumor-specific gene amplification in many human cancers, and has been identified as a human oncogene. In addition to its role in transformed growth, PKC-iota also promotes invasion, chemoresistance, and tumor cell survival. Expression profiling of PKC-iota is a prognostic marker of poor clinical outcome in several human cancers. PKC-iota also plays a role in establishing cell polarity, and has critical embryonic functions.