FIH-1-Mint3 axis does not control HIF-1α transcriptional activity in nucleus pulposus cells

Yuichiro Hirose, Zariel I. Johnson, Zachary R. Schoepflin, Dessislava Z. Markova, Kazuhiro Chiba, Yoshiaki Toyama, Irving M. Shapiro, Makarand V. Risbud

研究成果: Article査読

18 被引用数 (Scopus)

抄録

The objective of this study was to determine the role of FIH-1 in regulating HIF-1 activity in the nucleus pulposus (NP) cells and the control of this regulation by binding and sequestration of FIH-1 by Mint3. FIH-1 and Mint3 were both expressed in the NP and were shown to strongly co-localize within the cell nucleus. Although both mRNA and protein expression of FIH-1 decreased in hypoxia, only Mint3 protein levels were hypoxiasensitive. Overexpression of FIH-1 was able to reduce HIF-1 function, as seen by changes in activities of hypoxia response element-luciferase reporter and HIF-1α-C-TAD and HIF-2α-TAD. Moreover, co-transfection of either full-length Mint3 or the N terminus of Mint3 abrogated FIH-1-dependent reduction in HIF-1 activity under both normoxia and hypoxia. Nuclear levels of FIH-1 and Mint3 decreased in hypoxia, and the use of specific nuclear import and export inhibitors clearly showed that cellular compartmentalization of overexpressed FIH-1 was critical for its regulation of HIF-1 activity in NP cells. Interestingly, microarray results after stable silencing of FIH-1 showed no significant changes in transcripts of classical HIF-1 target genes. However, expression of several other transcripts, including those of the Notch pathway, changed in FIH-1-silenced cells. Moreover, co-transfection of Notch-ICD could restore suppression of HIF-1-TAD activity by exogenous FIH-1. Taken together, these results suggest that, possibly due to low endogenous levels and/or preferential association with substrates such as Notch, FIH-1 activity does not represent a major mechanism by which NP cells control HIF-1-dependent transcription, a testament to their adaptation to a unique hypoxic niche.

本文言語English
ページ(範囲)20594-20605
ページ数12
ジャーナルJournal of Biological Chemistry
289
30
DOI
出版ステータスPublished - 2014 7月 25

ASJC Scopus subject areas

  • 生化学
  • 分子生物学
  • 細胞生物学

フィンガープリント

「FIH-1-Mint3 axis does not control HIF-1α transcriptional activity in nucleus pulposus cells」の研究トピックを掘り下げます。これらがまとまってユニークなフィンガープリントを構成します。

引用スタイル