Prolyl Hydroxylase Domain Protein 2 (PHD2) Binds a Pro-Xaa-Leu-Glu Motif, Linking it to the Heat Shock Protein 90 Pathway.

University of Pennsylvania, United States.
Journal of Biological Chemistry (Impact Factor: 4.6). 02/2013; 288(14). DOI: 10.1074/jbc.M112.440552
Source: PubMed

ABSTRACT Prolyl Hydroxylase Domain protein 2 (PHD2, also known as Egg Laying Defective Nine homolog 1) is a key oxygen-sensing protein in metazoans. In an oxygen-dependent manner, PHD2 site-specifically prolyl hydroxylates the master transcription factor of the hypoxic response, Hypoxia Inducible Factor-α (HIF-α), thereby targeting HIF-α for degradation. In the present report, we show that the Heat Shock Protein 90 (HSP90) co-chaperones p23 and FKBP38 interact via a conserved Pro-Xaa-Leu-Glu motif (where Pro = Proline, Xaa = any amino acid, Leu = Leucine, Glu = Glutamic acid) in these proteins with the N-terminal Myeloid Nervy and DEAF-1 (MYND)-type zinc finger of PHD2. Knockdown of p23 augments hypoxia-induced HIF-1α protein levels and HIF target genes. We propose that p23 recruits PHD2 to the HSP90 machinery to facilitate HIF-1α hydroxylation. These findings identify a link between two ancient pathways--the PHD:HIF and the HSP90 pathways--and suggest that this link was established concurrent with the emergence of the PHD:HIF pathway in evolution.

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