Abstract
Hypoxia-inducible factor 1 (HIF-1) is a heterodimeric transcription factor that functions as a master regulator of oxygen homeostasis. The HIF-1α subunit is subjected to O2-dependent prolyl hydroxylation leading to ubiquitination by the von Hippel-Lindau protein (VHL)-Elongin C ubiquitin-ligase complex and degradation by the 26 S proteasome. In this study, we demonstrate that spermidine/spermine-N1-acetyltransferase (SSAT) 2 plays an essential role in this process. SSAT2 binds to HIF-1α, VHL, and Elongin C and promotes ubiquitination of hydroxylated HIF-1α by stabilizing the interaction of VHL and Elongin C. Multivalent interactions by SSAT2 provide a mechanism to ensure efficient complex formation, which is necessary for the extremely rapid ubiquitination and degradation of HIF-1α that is observed in oxygenated cells.
Original language | English (US) |
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Pages (from-to) | 23572-23580 |
Number of pages | 9 |
Journal | Journal of Biological Chemistry |
Volume | 282 |
Issue number | 32 |
DOIs | |
State | Published - Aug 10 2007 |
Externally published | Yes |
All Science Journal Classification (ASJC) codes
- Molecular Biology
- Biochemistry
- Cell Biology