Display Settings:

Format

Send to:

Choose Destination
See comment in PubMed Commons below
EMBO J. 2001 Jul 16;20(14):3800-10.

Phosphorylation of serine 230 promotes inducible transcriptional activity of heat shock factor 1.

Author information

  • 1Turku Centre for Biotechnology, University of Turku, Abo Akademi University, Finland.

Abstract

Heat shock factor 1 (HSF1) is a serine-rich constitutively phosphorylated mediator of the stress response. Upon stress, HSF1 forms DNA-binding trimers, relocalizes to nuclear granules, undergoes inducible phosphorylation and acquires the properties of a transactivator. HSF1 is phosphorylated on multiple sites, but the sites and their function have remained an enigma. Here, we have analyzed sites of endogenous phosphorylation on human HSF1 and developed a phosphopeptide antibody to identify Ser230 as a novel in vivo phosphorylation site. Ser230 is located in the regulatory domain of HSF1, and promotes the magnitude of the inducible transcriptional activity. Ser230 lies within a consensus site for calcium/calmodulin-dependent protein kinase II (CaMKII), and CaMKII overexpression enhances both the level of in vivo Ser230 phosphorylation and transactivation of HSF1. The importance of Ser230 was further established by the S230A HSF1 mutant showing markedly reduced activity relative to wild-type HSF1 when expressed in hsf1(-/-) cells. Our study provides the first evidence that phosphorylation is essential for the transcriptional activity of HSF1, and hence for induction of the heat shock response.

PMID:
11447121
[PubMed - indexed for MEDLINE]
PMCID:
PMC125548
Free PMC Article

Images from this publication.See all images (7)Free text

PubMed Commons home

PubMed Commons

0 comments
How to join PubMed Commons

    Supplemental Content

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