4ra5
From Proteopedia
Current revision
Human Protein Kinase C THETA IN COMPLEX WITH LIGAND COMPOUND 11a (6-[(1,3-Dimethyl-azetidin-3-yl)-methyl-amino]-4(R)-methyl-7-phenyl-2,10-dihydro-9-oxa-1,2,4a-triaza-phenanthren-3-one)
Structural highlights
FunctionKPCT_HUMAN Calcium-independent, phospholipid- and diacylglycerol (DAG)-dependent serine/threonine-protein kinase that mediates non-redundant functions in T-cell receptor (TCR) signaling, including T-cells activation, proliferation, differentiation and survival, by mediating activation of multiple transcription factors such as NF-kappa-B, JUN, NFATC1 and NFATC2. In TCR-CD3/CD28-co-stimulated T-cells, is required for the activation of NF-kappa-B and JUN, which in turn are essential for IL2 production, and participates to the calcium-dependent NFATC1 and NFATC2 transactivation. Mediates the activation of the canonical NF-kappa-B pathway (NFKB1) by direct phosphorylation of CARD11 on several serine residues, inducing CARD11 association with lipid rafts and recruitment of the BCL10-MALT1 complex, which then activates IKK complex, resulting in nuclear translocation and activation of NFKB1. May also play an indirect role in activation of the non-canonical NF-kappa-B (NFKB2) pathway. In the signaling pathway leading to JUN activation, acts by phosphorylating the mediator STK39/SPAK and may not act through MAP kinases signaling. Plays a critical role in TCR/CD28-induced NFATC1 and NFATC2 transactivation by participating in the regulation of reduced inositol 1,4,5-trisphosphate generation and intracellular calcium mobilization. After costimulation of T-cells through CD28 can phosphorylate CBLB and is required for the ubiquitination and subsequent degradation of CBLB, which is a prerequisite for the activation of TCR. During T-cells differentiation, plays an important role in the development of T-helper 2 (Th2) cells following immune and inflammatory responses, and, in the development of inflammatory autoimmune diseases, is necessary for the activation of IL17-producing Th17 cells. May play a minor role in Th1 response. Upon TCR stimulation, mediates T-cell protective survival signal by phosphorylating BAD, thus protecting T-cells from BAD-induced apoptosis, and by up-regulating BCL-X(L)/BCL2L1 levels through NF-kappa-B and JUN pathways. In platelets, regulates signal transduction downstream of the ITGA2B, CD36/GP4, F2R/PAR1 and F2RL3/PAR4 receptors, playing a positive role in 'outside-in' signaling and granule secretion signal transduction. May relay signals from the activated ITGA2B receptor by regulating the uncoupling of WASP and WIPF1, thereby permitting the regulation of actin filament nucleation and branching activity of the Arp2/3 complex. May mediate inhibitory effects of free fatty acids on insulin signaling by phosphorylating IRS1, which in turn blocks IRS1 tyrosine phosphorylation and downstream activation of the PI3K/AKT pathway. Phosphorylates MSN (moesin) in the presence of phosphatidylglycerol or phosphatidylinositol. Phosphorylates PDPK1 at 'Ser-504' and 'Ser-532' and negatively regulates its ability to phosphorylate PKB/AKT1.[1] [2] [3] [4] [5] [6] [7] [8] Publication Abstract from PubMedWe previously demonstrated that selective inhibition of Protein Kinase C theta (PKCtheta) with triazinone 1 resulted in dose-dependent reduction of paw swelling in a mouse model of arthritis.1, 2 However, a high concentration was required for efficacy thus providing only a minimal safety window. Herein we describe a strategy to deliver safer compounds based on the hypothesis that optimizing potency in concert with good oral pharmacokinetic (PK) properties would enable in vivo efficacy at reduced exposures resulting in an improved safety window. Ultimately, transformation of 1 yielded analogues which demonstrated excellent potency and PK, and fully inhibited IL-2 production in an acute model. In spite of good exposure, twice-a-day treatment with 17l in the glucose-6-phosphate isomerase (GPI) chronic in vivo mouse model of arthritis yielded only moderate efficacy. On the basis of the exposure achieved, we conclude that PKCtheta inhibition alone is insufficient for complete efficacy in this rodent arthritis model. Optimized Protein Kinase C theta (PKCtheta) Inhibitors Reveal Only Modest Anti-Inflammatory Efficacy in a Rodent Model of Arthritis.,George DM, Breinlinger EC, Argiriadi MA, Zhang Y, Wang J, Bansal-Pakala P, Duignan DB, Honore P, Lang Q, Mittelstadt S, Rundell L, Schwartz A, Sun J, Edmunds JJ J Med Chem. 2014 Sep 25. PMID:25254961[9] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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