| UniProt functional annotation for P68403 | |||
| UniProt code: P68403. |
| Organism: | Rattus norvegicus (Rat). | |
| Taxonomy: | Eukaryota; Metazoa; Chordata; Craniata; Vertebrata; Euteleostomi; Mammalia; Eutheria; Euarchontoglires; Glires; Rodentia; Myomorpha; Muroidea; Muridae; Murinae; Rattus. | |
| Function: | Calcium-activated, phospholipid- and diacylglycerol (DAG)- dependent serine/threonine-protein kinase involved in various cellular processes such as regulation of the B-cell receptor (BCR) signalosome, oxidative stress-induced apoptosis, androgen receptor-dependent transcription regulation, insulin signaling and endothelial cells proliferation. Plays a key role in B-cell activation by regulating BCR- induced NF-kappa-B activation. Mediates the activation of the canonical NF-kappa-B pathway (NFKB1) by direct phosphorylation of CARD11/CARMA1 at 'Ser-559', 'Ser-644' and 'Ser-652'. Phosphorylation induces CARD11/CARMA1 association with lipid rafts and recruitment of the BCL10-MALT1 complex as well as MAP3K7/TAK1, which then activates IKK complex, resulting in nuclear translocation and activation of NFKB1. Plays a direct role in the negative feedback regulation of the BCR signaling, by down-modulating BTK function via direct phosphorylation of BTK at 'Ser-180', which results in the alteration of BTK plasma membrane localization and in turn inhibition of BTK activity. Involved in apoptosis following oxidative damage: in case of oxidative conditions, specifically phosphorylates 'Ser-36' of isoform p66Shc of SHC1, leading to mitochondrial accumulation of p66Shc, where p66Shc acts as a reactive oxygen species producer. Acts as a coactivator of androgen receptor (ANDR)-dependent transcription, by being recruited to ANDR target genes and specifically mediating phosphorylation of 'Thr-6' of histone H3 (H3T6ph), a specific tag for epigenetic transcriptional activation that prevents demethylation of histone H3 'Lys-4' (H3K4me) by LSD1/KDM1A. In insulin signaling, may function downstream of IRS1 in muscle cells and mediate insulin-dependent DNA synthesis through the RAF1-MAPK/ERK signaling cascade. Participates in the regulation of glucose transport in adipocytes by negatively modulating the insulin- stimulated translocation of the glucose transporter SLC2A4/GLUT4. Phosphorylates SLC2A1/GLUT1, promoting glucose uptake by SLC2A1/GLUT1. Under high glucose in pancreatic beta-cells, is probably involved in the inhibition of the insulin gene transcription, via regulation of MYC expression. In endothelial cells, activation of PRKCB induces increased phosphorylation of RB1, increased VEGFA-induced cell proliferation, and inhibits PI3K/AKT-dependent nitric oxide synthase (NOS3/eNOS) regulation by insulin, which causes endothelial dysfunction. Also involved in triglyceride homeostasis (By similarity). Phosphorylates ATF2 which promotes cooperation between ATF2 and JUN, activating transcription. {ECO:0000250|UniProtKB:P05771, ECO:0000250|UniProtKB:P68404, ECO:0000269|PubMed:10938109, ECO:0000269|PubMed:11714718, ECO:0000269|PubMed:19176525}. | |
| Catalytic activity: | Reaction=ATP + L-seryl-[protein] = ADP + H(+) + O-phospho-L-seryl- [protein]; Xref=Rhea:RHEA:17989, Rhea:RHEA-COMP:9863, Rhea:RHEA- COMP:11604, ChEBI:CHEBI:15378, ChEBI:CHEBI:29999, ChEBI:CHEBI:30616, ChEBI:CHEBI:83421, ChEBI:CHEBI:456216; EC=2.7.11.13; | |
| Catalytic activity: | Reaction=ATP + L-threonyl-[protein] = ADP + H(+) + O-phospho-L- threonyl-[protein]; Xref=Rhea:RHEA:46608, Rhea:RHEA-COMP:11060, Rhea:RHEA-COMP:11605, ChEBI:CHEBI:15378, ChEBI:CHEBI:30013, ChEBI:CHEBI:30616, ChEBI:CHEBI:61977, ChEBI:CHEBI:456216; EC=2.7.11.13; | |
| Cofactor: | Name=Ca(2+); Xref=ChEBI:CHEBI:29108; Evidence={ECO:0000255|PROSITE-ProRule:PRU00041, ECO:0000269|PubMed:21215369, ECO:0000269|PubMed:9817842}; Note=Binds 3 Ca(2+) ions per subunit. The ions are bound to the C2 domain. {ECO:0000269|PubMed:21215369, ECO:0000269|PubMed:9817842}; | |
| Activity regulation: | Classical (or conventional) PKCs (PRKCA, PRKCB and PRKCG) are activated by calcium and diacylglycerol (DAG) in the presence of phosphatidylserine. Three specific sites; Thr-500 (activation loop of the kinase domain), Thr-642 (turn motif) and Ser- 661 (hydrophobic region), need to be phosphorylated for its full activation. Specifically inhibited by enzastaurin (LY317615) (By similarity). {ECO:0000250}. | |
| Subunit: | Interacts with PDK1. Interacts in vitro with PRKCBP1. Interacts with PHLPP1 and PHLPP2; both proteins mediate its dephosphorylation. Interacts with KDM1A/LSD1, PKN1 and ANDR (By similarity). {ECO:0000250}. | |
| Subcellular location: | Cytoplasm. Nucleus {ECO:0000250}. Membrane; Peripheral membrane protein. | |
| Ptm: | Phosphorylation on Thr-500 of isoform beta-I, within the activation loop, renders it competent to autophosphorylate. Subsequent autophosphorylation of Thr-642 maintains catalytic competence, and autophosphorylation on Ser-661 appears to release the kinase into the cytosol. Similarly, isoform beta-II is autophosphorylated on 'Thr-641' and 'Ser-660', subsequent to phosphorylation on Thr-500. Autophosphorylated on other sites i.e. in the N-terminal and hinge regions have no effect on enzyme activity. Phosphorylation at Tyr-662 by SYK induces binding with GRB2 and contributes to the activation of MAPK/ERK signaling cascade. {ECO:0000269|PubMed:21215369, ECO:0000269|PubMed:7961692, ECO:0000269|PubMed:8327493, ECO:0000269|PubMed:8749392}. | |
| Similarity: | Belongs to the protein kinase superfamily. AGC Ser/Thr protein kinase family. PKC subfamily. {ECO:0000305}. | |
Annotations taken from UniProtKB at the EBI.