3u9h
Complex structure of human tankyrase 2 with nicotinamideComplex structure of human tankyrase 2 with nicotinamide
Structural highlights
Function[TNKS2_HUMAN] Poly-ADP-ribosyltransferase involved in various processes such as Wnt signaling pathway, telomere length and vesicle trafficking. Acts as an activator of the Wnt signaling pathway by mediating poly-ADP-ribosylation of AXIN1 and AXIN2, 2 key components of the beta-catenin destruction complex: poly-ADP-ribosylated target proteins are recognized by RNF146, which mediates their ubiquitination and subsequent degradation. Also mediates poly-ADP-ribosylation of BLZF1 and CASC3, followed by recruitment of RNF146 and subsequent ubiquitination. Mediates poly-ADP-ribosylation of TERF1, thereby contributing to the regulation of telomere length. May also regulate vesicle trafficking and modulate the subcellular distribution of SLC2A4/GLUT4-vesicles.[1] [2] [3] [4] Publication Abstract from PubMedTankyrases are poly(ADP-ribose) polymerases that have many cellular functions. They play pharmaceutically important roles, at least in telomere homeostasis and Wnt signaling, by covalently ADP-ribosylating target proteins and consequently regulating their functions. These features make tankyrases potential targets for treatment of cancer. We report here crystal structures of human tankyrase 2 catalytic fragment in complex with a by-product, nicotinamide and with selective inhibitors of tankyrases (IWR-1) and PARPs 1 and 2 (olaparib). Binding of these inhibitors to tankyrase 2 induce specific conformational changes. The crystal structures explain the selectivity of the inhibitors, reveal the flexibility of a substrate binding loop and explain existing structure-activity relationship data. The first crystal structure of a PARP enzyme in complex with a potent inhibitor, IWR-1, which does not bind to the widely-utilized nicotinamide-binding site makes the structure valuable also for development of PARP inhibitors in general. Structural Basis of Selective Inhibition of Human Tankyrases.,Narwal M, Venkannagari H, Lehtio L J Med Chem. 2012 Jan 10. PMID:22233320[5] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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