| Structural highlights
3pfq is a 1 chain structure with sequence from Buffalo rat. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance.
| | Ligands: | , , |
| NonStd Res: | , |
| Related: | 2i0e, 1a25 |
| Gene: | Prkcb, Pkcb, Prkcb1 (Buffalo rat) |
| Activity: | Protein kinase C, with EC number 2.7.11.13 |
| Resources: | FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT |
Function
[KPCB_RAT] 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. May participate in the regulation of glucose transport in adipocytes by negatively modulating the insulin-stimulated translocation of the glucose transporter SLC2A4/GLUT4. 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).[1] [2]
Publication Abstract from PubMed
Protein kinase C (PKC) isozymes are the paradigmatic effectors of lipid signaling. PKCs translocate to cell membranes and are allosterically activated upon binding of the lipid diacylglycerol to their C1A and C1B domains. The crystal structure of full-length protein kinase C betaII was determined at 4.0 A, revealing the conformation of an unexpected intermediate in the activation pathway. Here, the kinase active site is accessible to substrate, yet the conformation of the active site corresponds to a low-activity state because the ATP-binding side chain of Phe629 of the conserved NFD motif is displaced. The C1B domain clamps the NFD helix in a low-activity conformation, which is reversed upon membrane binding. A low-resolution solution structure of the closed conformation of PKCbetaII was derived from small-angle X-ray scattering. Together, these results show how PKCbetaII is allosterically regulated in two steps, with the second step defining a novel protein kinase regulatory mechanism.
Crystal structure and allosteric activation of protein kinase C betaII.,Leonard TA, Rozycki B, Saidi LF, Hummer G, Hurley JH Cell. 2011 Jan 7;144(1):55-66. PMID:21215369[3]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
See Also
References
- ↑ Formisano P, Oriente F, Fiory F, Caruso M, Miele C, Maitan MA, Andreozzi F, Vigliotta G, Condorelli G, Beguinot F. Insulin-activated protein kinase Cbeta bypasses Ras and stimulates mitogen-activated protein kinase activity and cell proliferation in muscle cells. Mol Cell Biol. 2000 Sep;20(17):6323-33. PMID:10938109
- ↑ Kaneto H, Suzuma K, Sharma A, Bonner-Weir S, King GL, Weir GC. Involvement of protein kinase C beta 2 in c-myc induction by high glucose in pancreatic beta-cells. J Biol Chem. 2002 Feb 1;277(5):3680-5. Epub 2001 Nov 19. PMID:11714718 doi:http://dx.doi.org/10.1074/jbc.M109647200
- ↑ Leonard TA, Rozycki B, Saidi LF, Hummer G, Hurley JH. Crystal structure and allosteric activation of protein kinase C betaII. Cell. 2011 Jan 7;144(1):55-66. PMID:21215369 doi:10.1016/j.cell.2010.12.013
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