Previous Article | Next Article ![]()
Mol. Cell. Biol., Dec 1996, 7018-7030, Vol 16, No. 12
A Orosz, J Wisniewski and C Wu
Heat shock transcription factor (HSF) is a multidomain protein that exists
as a monomer under normal conditions and is reversibly induced upon heat
shock to a trimeric state that binds to DNA with high affinity. The
maintenance of the monomeric state is dependent on hydrophobic heptad
repeats located at the amino- and carboxy-terminal regions which have been
proposed to form an intramolecular coiled-coil structure. In a systematic
deletion analysis to identify other regions of HSF that may be required to
regulate its oligomeric state, we have found that local sequences
encompassing the carboxy-terminal end of the DNA binding domain and a broad
region of HSF between the heptad repeats also contribute to this
regulation. Immunocytochemical analysis of mutant HSF proteins revealed a
canonical motif required for nuclear localization. HSF proteins lacking the
nuclear localization signal remain in the cytoplasm, but these HSFs
nonetheless exhibit reversible heat stress-inducible trimerization. The
results indicate that the signals that regulate HSF trimerization operate
in both the nuclear and cytoplasmic compartments of the cell.
Copyright © 1996, American Society for Microbiology
Regulation of Drosophila heat shock factor trimerization: global sequence requirements and independence of nuclear localization
Laboratory of Molecular Cell Biology, National Cancer Institute, Bethesda, Maryland 20892-4255, USA.
This article has been cited by other articles:
Copyright © 2009 by the American Society for Microbiology. For an alternate route to Journals.ASM.org, visit: http://intl-journals.asm.org | More Info»