PKCH
Calcium-independent, phospholipid- and diacylglycerol (DAG)-dependent serine/threonine-protein kinase that is involved in the regulation of cell differentiation in keratinocytes and pre-B cell receptor, mediates regulation of epithelial tight junction integrity and foam cell formation, and is required for glioblastoma proliferation and apoptosis prevention in MCF-7 cells. In keratinocytes, binds and activates the tyrosine kinase FYN, which in turn blocks epidermal growth factor receptor (EGFR) signaling and leads to keratinocyte growth arrest and differentiation. Associates with the cyclin CCNE1-CDK2-p27Kip1 complex and inhibits CDK2 kinase activity, leading to RB1 dephosphorylation and thereby G1 arrest in keratinocytes. In association with RALA activates actin depolymerization, which is necessary for keratinocyte differentiation. In the pre-B cell receptor signaling, functions downstream of BLNK by up-regulating IRF4, which in turn activates L chain gene rearrangement. Regulates epithelial tight junctions (TJs) by phosphorylating occludin (OCLN) on threonine residues, which is necessary for the assembly and maintenance of TJs. In association with PLD2 and via TLR4 signaling, is involved in lipopolysaccharide (LPS)-induced RGS2 down-regulation and foam cell formation. Upon PMA stimulation, mediates glioblastoma cell proliferation by activating the mTOR pathway, the PI3K/AKT pathway and the ERK1- dependent phosphorylation of ELK1. Involved in the protection of glioblastoma cells from irradiation-induced apoptosis by preventing caspase-9 activation. In camptothecin-treated MCF-7 cells, regulates NF-kappa-B upstream signaling by activating IKBKB, and confers protection against DNA damage-induced apoptosis. Interacts with FYN and RALA. Interacts with DGKQ. Most abundant in lung, less in heart and skin. Novel PKCs (PRKCD, PRKCE, PRKCH and PRKCQ) are calcium-insensitive, but activated by diacylglycerol (DAG) and phosphatidylserine. Three specific sites; Thr-513 (activation loop of the kinase domain), Thr-656 (turn motif) and Ser-675 (hydrophobic region), need to be phosphorylated for its full activation. Belongs to the protein kinase superfamily. AGC Ser/Thr protein kinase family. PKC subfamily. Note: This description may include information from UniProtKB.
Protein type: Protein kinase, AGC; Kinase, protein; EC 2.7.11.13; Protein kinase, Ser/Thr (non-receptor); AGC group; PKC family; Eta subfamily
Molecular Function: protein kinase C activity; enzyme binding; metal ion binding; Ral GTPase binding; ATP binding
Biological Process: platelet activation; positive regulation of B cell receptor signaling pathway; blood coagulation; signal transduction; protein amino acid phosphorylation; positive regulation of keratinocyte differentiation; activation of NF-kappaB transcription factor
SS: The number of records in which this modification site was determined using site-specific methods. SS methods include amino acid sequencing, site-directed mutagenesis, modification site-specific antibodies, specific MS strategies, etc.
