2qc9

Publication Abstract from PubMed

The stability and activity of hypoxia-inducible factor (HIF) are regulated by the post-translational hydroxylation of specific prolyl and asparaginyl residues. We show that the HIF asparaginyl hydroxylase, factor inhibiting HIF (FIH), also catalyzes hydroxylation of highly conserved asparaginyl residues within ankyrin repeat (AR) domains (ARDs) of endogenous Notch receptors. AR hydroxylation decreases the extent of ARD binding to FIH while not affecting signaling through the canonical Notch pathway. ARD proteins were found to efficiently compete with HIF for FIH-dependent hydroxylation. Crystallographic analyses of the hydroxylated Notch ARD (2.35A) and of Notch peptides bound to FIH (2.4-2.6A) reveal the stereochemistry of hydroxylation on the AR and imply that significant conformational changes are required in the ARD fold in order to enable hydroxylation at the FIH active site. We propose that ARD proteins function as natural inhibitors of FIH and that the hydroxylation status of these proteins provides another oxygen-dependent interface that modulates HIF signaling.

Asparaginyl hydroxylation of the Notch ankyrin repeat domain by factor inhibiting hypoxia-inducible factor.,Coleman ML, McDonough MA, Hewitson KS, Coles C, Mecinovic J, Edelmann M, Cook KM, Cockman ME, Lancaster DE, Kessler BM, Oldham NJ, Ratcliffe PJ, Schofield CJ J Biol Chem. 2007 Aug 17;282(33):24027-38. Epub 2007 Jun 15. PMID:17573339^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.