Format

Send to:

Choose Destination
See comment in PubMed Commons below
J Biol Chem. 2012 Feb 24;287(9):6139-49. doi: 10.1074/jbc.M111.278630. Epub 2012 Jan 4.

Four-and-a-half LIM domain proteins inhibit transactivation by hypoxia-inducible factor 1.

Author information

  • 1Graduate Training Program in Cellular & Molecular Medicine, The Johns Hopkins University School of Medicine, Baltimore, Maryland 21205, USA.

Abstract

Hypoxia-inducible factor 1 (HIF-1) is a transcription factor that promotes angiogenesis, metabolic reprogramming, and other critical aspects of cancer biology. The four-and-a-half LIM domain (FHL) proteins are a family of LIM domain-only proteins implicated in transcriptional regulation and suppression of tumor growth. Here we describe functional interactions between the FHL proteins and HIF-1. FHL1-3 inhibit HIF-1 transcriptional activity and HIF-1α transactivation domain function by oxygen-independent mechanisms. FHL2 directly interacts with HIF-1α to repress transcriptional activity. FHL1 binds to the p300/CBP co-activators and disrupts binding with HIF-1α. FHL3 does not bind to HIF-1α or p300, indicating that it regulates transactivation by a novel molecular mechanism. Expression of the FHL proteins increased upon HIF-1α induction, suggesting the existence of a feedback loop. These results identify FHL proteins as negative regulators of HIF-1 activity, which may provide a mechanism by which they suppress tumor growth.

PMID:
22219185
[PubMed - indexed for MEDLINE]
PMCID:
PMC3307273
Free PMC Article
PubMed Commons home

PubMed Commons

0 comments
How to join PubMed Commons

    Supplemental Content

    Full text links

    Icon for HighWire Icon for PubMed Central
    Loading ...
    Write to the Help Desk