Microtubule disruption targets HIF-1alpha mRNA to cytoplasmic P-bodies for translational repression

J Cell Biol. 2011 Jan 10;192(1):83-99. doi: 10.1083/jcb.201004145.

Abstract

The hypoxia inducible factor 1α (HIF-1α) is overexpressed in solid tumors, driving tumor angiogenesis and survival. However, the mechanisms regulating HIF-1α expression in solid tumors are not fully understood. In this study, we find that microtubule integrity and dynamics are intricately involved in orchestrating HIF-1α translation. HIF-1α messenger RNA (mRNA) traffics on dynamic microtubules when it is actively translated. Microtubule perturbation by taxol (TX) and other microtubule-targeting drugs stalls HIF-1α mRNA transport and releases it from polysomes, suppressing its translation. Immunoprecipitation of the P-body component Argonaute 2 (Ago2) after microtubule disruption shows significant enrichment of HIF-1α mRNAs and HIF-targeting microRNAs (miRNAs). Inhibition of HIF-repressing miRNAs or Ago2 knockdown abrogates TX's ability to suppress HIF-1α translation. Interestingly, microtubule repolymerization after nocodazole washout allows HIF-1α mRNA to reenter active translation, suggesting that microtubule dynamics exert tight yet reversible control over HIF-1α translation. Collectively, we provide evidence for a new mechanism of microtubule-dependent HIF-1α translation with important implications for cell biology.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • 3' Untranslated Regions / genetics
  • Argonaute Proteins
  • Chemical Precipitation / drug effects
  • Cytoplasmic Structures / drug effects
  • Cytoplasmic Structures / metabolism*
  • Eukaryotic Initiation Factor-2 / metabolism
  • Green Fluorescent Proteins / metabolism
  • HeLa Cells
  • Humans
  • Hypoxia-Inducible Factor 1, alpha Subunit / genetics*
  • Hypoxia-Inducible Factor 1, alpha Subunit / metabolism
  • Microtubules / drug effects
  • Microtubules / metabolism*
  • Nocodazole / pharmacology
  • Paclitaxel / pharmacology
  • Polymerization / drug effects
  • Protein Binding / drug effects
  • Protein Biosynthesis* / drug effects
  • RNA Transport* / drug effects
  • RNA, Messenger / genetics
  • RNA, Messenger / metabolism
  • Recombinant Fusion Proteins / metabolism
  • Tubulin / metabolism

Substances

  • 3' Untranslated Regions
  • AGO2 protein, human
  • Argonaute Proteins
  • Eukaryotic Initiation Factor-2
  • Hypoxia-Inducible Factor 1, alpha Subunit
  • RNA, Messenger
  • Recombinant Fusion Proteins
  • Tubulin
  • Green Fluorescent Proteins
  • Paclitaxel
  • Nocodazole