5v1b

Structural highlights

Function

EGLN2_HUMAN Cellular oxygen sensor that catalyzes, under normoxic conditions, the post-translational formation of 4-hydroxyproline in hypoxia-inducible factor (HIF) alpha proteins. Hydroxylates a specific proline found in each of the oxygen-dependent degradation (ODD) domains (N-terminal, NODD, and C-terminal, CODD) of HIF1A. Also hydroxylates HIF2A. Has a preference for the CODD site for both HIF1A and HIF2A. Hydroxylated HIFs are then targeted for proteasomal degradation via the von Hippel-Lindau ubiquitination complex. Under hypoxic conditions, the hydroxylation reaction is attenuated allowing HIFs to escape degradation resulting in their translocation to the nucleus, heterodimerization with HIF1B, and increased expression of hypoxy-inducible genes. EGLN2 is involved in regulating hypoxia tolerance and apoptosis in cardiac and skeletal muscle. Also regulates susceptibility to normoxic oxidative neuronal death. Links oxygen sensing to cell cycle and primary cilia formation by hydroxylating the critical centrosome component CEP192 which promotes its ubiquitination and subsequent proteasomal degradation. Hydroxylates IKBKB, mediating NF-kappaB activation in hypoxic conditions. Target proteins are preferentially recognized via a LXXLAP motif.^{[1] [2] [3] [4] [5] [6]}

See Also

• Polyl hydroxylase domain 3D structures

References

1. ↑ Epstein AC, Gleadle JM, McNeill LA, Hewitson KS, O'Rourke J, Mole DR, Mukherji M, Metzen E, Wilson MI, Dhanda A, Tian YM, Masson N, Hamilton DL, Jaakkola P, Barstead R, Hodgkin J, Maxwell PH, Pugh CW, Schofield CJ, Ratcliffe PJ. C. elegans EGL-9 and mammalian homologs define a family of dioxygenases that regulate HIF by prolyl hydroxylation. Cell. 2001 Oct 5;107(1):43-54. PMID:11595184
2. ↑ Huang J, Zhao Q, Mooney SM, Lee FS. Sequence determinants in hypoxia-inducible factor-1alpha for hydroxylation by the prolyl hydroxylases PHD1, PHD2, and PHD3. J Biol Chem. 2002 Oct 18;277(42):39792-800. Epub 2002 Aug 13. PMID:12181324 doi:http://dx.doi.org/10.1074/jbc.M206955200
3. ↑ Tian YM, Mole DR, Ratcliffe PJ, Gleadle JM. Characterization of different isoforms of the HIF prolyl hydroxylase PHD1 generated by alternative initiation. Biochem J. 2006 Jul 1;397(1):179-86. PMID:16509823 doi:http://dx.doi.org/10.1042/BJ20051996
4. ↑ Cummins EP, Berra E, Comerford KM, Ginouves A, Fitzgerald KT, Seeballuck F, Godson C, Nielsen JE, Moynagh P, Pouyssegur J, Taylor CT. Prolyl hydroxylase-1 negatively regulates IkappaB kinase-beta, giving insight into hypoxia-induced NFkappaB activity. Proc Natl Acad Sci U S A. 2006 Nov 28;103(48):18154-9. Epub 2006 Nov 17. PMID:17114296 doi:http://dx.doi.org/10.1073/pnas.0602235103
5. ↑ Yasumoto K, Kowata Y, Yoshida A, Torii S, Sogawa K. Role of the intracellular localization of HIF-prolyl hydroxylases. Biochim Biophys Acta. 2009 May;1793(5):792-7. doi: 10.1016/j.bbamcr.2009.01.014. , Epub 2009 Feb 5. PMID:19339211 doi:10.1016/j.bbamcr.2009.01.014
6. ↑ Moser SC, Bensaddek D, Ortmann B, Maure JF, Mudie S, Blow JJ, Lamond AI, Swedlow JR, Rocha S. PHD1 links cell-cycle progression to oxygen sensing through hydroxylation of the centrosomal protein Cep192. Dev Cell. 2013 Aug 26;26(4):381-92. doi: 10.1016/j.devcel.2013.06.014. Epub 2013 , Aug 8. PMID:23932902 doi:http://dx.doi.org/10.1016/j.devcel.2013.06.014