title: Cobalt- and nickel-binding property of cullin-2.
abstract: Treatment with divalent metal ions such as cobalt (Co(2+)) or nickel (Ni(2+)) result in the stabilization of hypoxia-inducible factor-1alpha (HIF1alpha). Recently, HIF1alpha was shown to be ubiquitinated by an E3-ligase complex and be subsequently targeted for proteasomal degradation. In this study, we demonstrated that Co(2+) and Ni(2+) specifically bind to cullin-2. Mutant analysis revealed that cullin-2 possesses at least three sites for the binding. Furthermore, fluorescence spectroscopy revealed that only Co(2+) and Ni(2+) have the binding activity to cullin-2, but other metal ions, including Cu(2+), Ca(2+), Mg(2+), Mn(2+), and Zn(2+), did not. Finally, we found that Co(2+) and Ni(2+) do not bind to any components of the E3-ligase other than cullin-2, suggesting that cullin-2 is a key target of Co(2+) and Ni(2+). Interestingly, Co(2+) did not affect the complex formation of the ligase, suggesting that the metal binding to cullin-2 affects the function, but not the assembly of the E3-ligase.
authors.affiliation: Department of Cardiology, University of Texas M. D. Anderson Cancer Center, 1515 Holcombe Boulevard, Houston, TX 77030, USA.
authors.forename: Koichi
authors.initials: K
authors.lastname: Kanaya
authors.forename: Ah-Lim
authors.initials: AL
authors.lastname: Tsai
authors.forename: Tetsu
authors.initials: T
authors.lastname: Kamitani
mesh_terms: D000256:Adenoviridae / Q000235:genetics; D000818:Animals; D001665:Binding Sites; D015153:Blotting, Western; D019556:COS Cells; D018797:Cell Cycle Proteins / Q000737:chemistry* / Q000378:metabolism*; D002460:Cell Line; D003035:Cobalt / Q000737:chemistry* / Q000378:metabolism; D044842:Cullin Proteins; D018076:DNA, Complementary / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D004730:Endothelium, Vascular / Q000166:cytology; D005822:Genetic Vectors; D005982:Glutathione Transferase / Q000737:chemistry / Q000378:metabolism; D006801:Humans; D051795:Hypoxia-Inducible Factor 1, alpha Subunit; D008025:Ligases / Q000378:metabolism; D008274:Magnesium / Q000737:chemistry; D008345:Manganese / Q000737:chemistry; D009154:Mutation; D009532:Nickel / Q000737:chemistry* / Q000378:metabolism; D010957:Plasmids; D011233:Precipitin Tests; D011485:Protein Binding; D011993:Recombinant Fusion Proteins / Q000737:chemistry / Q000378:metabolism; D013050:Spectrometry, Fluorescence; D014157:Transcription Factors / Q000737:chemistry; D014158:Transcription, Genetic; D014162:Transfection; D044767:Ubiquitin-Protein Ligases; D014471:Umbilical Veins / Q000166:cytology; D015032:Zinc / Q000737:chemistry
chemical_list: C105153:CUL2 protein, human; D018797:Cell Cycle Proteins; D044842:Cullin Proteins; D018076:DNA, Complementary; C497442:HIF1A protein, human; D051795:Hypoxia-Inducible Factor 1, alpha Subunit; D011993:Recombinant Fusion Proteins; D014157:Transcription Factors; D003035:Cobalt; D008345:Manganese; D009532:Nickel; D044767:Ubiquitin-Protein Ligases; D005982:Glutathione Transferase; D008025:Ligases; D008274:Magnesium; D015032:Zinc