Induction of the heat shock pathway during hypoxia requires regulation of heat shock factor by hypoxia-inducible factor-1.
J Biol Chem
; 281(50): 38675-81, 2006 Dec 15.
Article
em En
| MEDLINE
| ID: mdl-17040902
ABSTRACT
Activation of heat shock proteins (Hsps) is critical to adaptation to low oxygen levels (hypoxia) and for enduring the oxidative stress of reoxygenation. Hsps are known to be regulated by heat shock factor (Hsf), but our results demonstrate an unexpected regulatory link between the oxygen-sensing and heat shock pathways. Hsf transcription is up-regulated during hypoxia due to direct binding by hypoxia-inducible factor-1 (HIF-1) to HIF-1 response elements in an Hsf intron. This increase in Hsf transcripts is necessary for full Hsp induction during hypoxia and reoxygenation. The HIF-1-dependent increase in Hsps has a functional impact, as reduced production of Hsps decreases viability of adult flies exposed to hypoxia and reoxygenation. Thus, HIF-1 control of Hsf transcriptional levels is a regulatory mechanism for sensitizing heat shock pathway activity in order to maximize production of protective Hsps. This cross-regulation represents a mechanism by which the low oxygen response pathway has assimilated complex new functions by regulating the key transcriptional activator of the heat shock pathway.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Fatores de Transcrição
/
Proteínas de Drosophila
/
Proteínas de Ligação a DNA
/
Fator 1 Induzível por Hipóxia
Limite:
Animals
Idioma:
En
Revista:
J Biol Chem
Ano de publicação:
2006
Tipo de documento:
Article