title: Hypoxia-inducible factor α subunit stabilization by NEDD8 conjugation is reactive oxygen species-dependent.
abstract: Hypoxia-inducible factor α proteins (HIF-αs) are regulated oxygen dependently and transactivate numerous genes essential for cellular adaptation to hypoxia. NEDD8, a member of the ubiquitin-like family, covalently binds to its substrate proteins, and thus, regulates their stabilities and functions. In the present study, we examined the possibility that the HIF signaling is regulated by the neddylation. HIF-1α expression and activity were inhibited by knocking down APPBP1 E1 enzyme for NEDD8 conjugation but enhanced by ectopically expressing NEDD8. HIF-1α and HIF-2α were identified to be covalently modified by NEDD8. NEDD8 stabilized HIF-1α even in normoxia and further increased its level in hypoxia, which also occurred in von Hippel-Lindau (VHL) protein- or p53-null cell lines. The HIF-1α-stabilizing effect of NEDD8 was diminished by antioxidants and mitochondrial respiratory chain blockers. This suggests that the NEDD8 effect is concerned with reactive oxygen species driven from mitochondria rather than with the prolyl hydroxylase (PHD)/VHL-dependent oxygen-sensing system. Based on these findings, we propose that NEDD8 is an ancillary player to regulate the stability of HIF-1α. Furthermore, given the positive role played by HIF-αs in cancer promotion, the NEDD8 conjugation process could be a potential target for cancer therapy.
authors.affiliation: Department of Physiology, Seoul National University College of Medicine, 28 Yongon-dong, Chongno-gu, Seoul 110-799, Korea.
authors.forename: Ji-Hye
authors.initials: JH
authors.lastname: Ryu
authors.forename: Shan-Hua
authors.initials: SH
authors.lastname: Li
authors.forename: Hyoung-Sook
authors.initials: HS
authors.lastname: Park
authors.forename: Jong-Wan
authors.initials: JW
authors.lastname: Park
authors.forename: Byunglan
authors.initials: B
authors.lastname: Lee
authors.forename: Yang-Sook
authors.initials: YS
authors.lastname: Chun
mesh_terms: D051792:Basic Helix-Loop-Helix Proteins / Q000737:chemistry / Q000378:metabolism; D057809:HEK293 Cells; D006801:Humans; D000860:Hypoxia / Q000378:metabolism*; D051795:Hypoxia-Inducible Factor 1, alpha Subunit / Q000235:genetics / Q000378:metabolism*; D000075687:NEDD8 Protein; D009369:Neoplasms / Q000378:metabolism; D011393:Procollagen-Proline Dioxygenase / Q000378:metabolism; D011485:Protein Binding / Q000502:physiology; D055550:Protein Stability; D021122:Protein Subunits / Q000235:genetics / Q000378:metabolism*; D034741:RNA, Small Interfering; D017382:Reactive Oxygen Species / Q000378:metabolism*; D015398:Signal Transduction / Q000502:physiology; D016159:Tumor Suppressor Protein p53 / Q000378:metabolism; D014452:Ubiquitins / Q000235:genetics / Q000378:metabolism*; D051794:Von Hippel-Lindau Tumor Suppressor Protein / Q000378:metabolism; D000099162:Endothelial PAS Domain-Containing Protein 1
chemical_list: D051792:Basic Helix-Loop-Helix Proteins; D051795:Hypoxia-Inducible Factor 1, alpha Subunit; D000075687:NEDD8 Protein; D011393:Procollagen-Proline Dioxygenase; D021122:Protein Subunits; D034741:RNA, Small Interfering; D017382:Reactive Oxygen Species; D016159:Tumor Suppressor Protein p53; D014452:Ubiquitins; D051794:Von Hippel-Lindau Tumor Suppressor Protein; D000099162:Endothelial PAS Domain-Containing Protein 1; C497442:HIF1A protein, human; C082860:NEDD8 protein, human; C495901:TP53 protein, human; C497446:VHL protein, human