scholarly journals Developmental regulation of the heat shock response by nuclear transport factor karyopherin-α3

Development ◽  
2001 ◽  
Vol 128 (17) ◽  
pp. 3349-3358 ◽  
Author(s):  
Xiang-dong Fang ◽  
Tianxin Chen ◽  
Kim Tran ◽  
Carl S. Parker
Keyword(s):  
Heat Shock ◽  
Nuclear Localization ◽  
Heat Shock Response ◽  
Nuclear Transport ◽  
Early Embryo ◽  
Nuclear Localization Sequence ◽  
Nuclear Targeting ◽  
Transport Factor ◽  
Shock Response ◽  
Hsp70 Induction

During early stages of Drosophila development the heat-shock response cannot be induced. It is reasoned that the adverse effects on cell cycle and cell growth brought about by Hsp70 induction must outweigh the beneficial aspects of Hsp70 induction in the early embryo. Although the Drosophila heat shock transcription factor (dHSF) is abundant in the early embryo it does not enter the nucleus in response to heat shock. In older embryos and in cultured cells the factor is localized within the nucleus in an apparent trimeric structure that binds DNA with high affinity. The domain responsible for nuclear localization upon stress resides between residues 390 and 420 of the dHSF. Using that domain as bait in a yeast two-hybrid system we now report the identification and cloning of a Drosophila nuclear transport protein karyopherin-α3 (dKap-α3). Biochemical methods demonstrate that the dKap-α3 protein binds specifically to the dHSF’s nuclear localization sequence (NLS). Furthermore, the dKap-α3 protein does not associate with NLSs that contain point mutations, which are not transported in vivo. Nuclear docking studies also demonstrate specific nuclear targeting of the NLS substrate by dKap-α3. Consistant with previous studies demonstrating that early Drosophila embryos are refractory to heat shock as a result of dHSF nuclear exclusion, we demonstrate that the early embryo is deficient in dKap-α3 protein through cycle 12. From cycle 13 onward the transport factor is present and the dHSF is localized within the nucleus thus allowing the embryo to respond to heat shock.

Indomethacin and ibuprofen induce Hsc70 nuclear localization and activation of the heat shock response in HeLa cells

2004 ◽  
Vol 313 (4) ◽  
pp. 863-870 ◽  
Author(s):  
Lucio Lagunas ◽  
C.Matthew Bradbury ◽  
Andrei Laszlo ◽  
Clayton R Hunt ◽  
David Gius
Keyword(s):  
Heat Shock ◽  
Nuclear Localization ◽  
Hela Cells ◽  
Heat Shock Response ◽  
Shock Response

Developmentally regulated nuclear transport of transcription factors in Drosophila embryos enable the heat shock response

Development ◽  
1998 ◽  
Vol 125 (23) ◽  
pp. 4841-4850 ◽  
Author(s):  
Z. Wang ◽  
S. Lindquist
Keyword(s):  
Transcription Factors ◽  
Heat Shock ◽  
Heat Shock Response ◽  
Nuclear Transport ◽  
Binding Activity ◽  
Spatiotemporal Pattern ◽  
Dna Binding Activity ◽  
Early Embryos ◽  
Shock Response ◽  
Drosophila Embryos

Hsp70 is a broadly conserved thermotolerance factor, but inhibits growth at normal temperatures and cannot be induced in early embryos. We report that in Drosophila embryos the temporal and spatial patterns of Hsp70 inducibility were unexpectedly complex, with striking differences between the soma and the germline. In both, regulation occurred at the level of transcription. During the refractory period for Hsp70 induction, HSF (heat-shock transcription factor) exhibited specific DNA-binding activity characteristic of activation in extracts of heated embryos. Remarkably, however, HSF was restricted to the cytoplasm in intact embryos even after heat shock. HSF moved from the cytoplasm to the nucleus in the absence of heat precisely when the capacity to induce Hsp70 was acquired (cycle 12 of the germline, cycle 13 in the soma). During oogenesis, Hsp70 inducibility was lost in nurse cells around stage 10, in a posterior-to-anterior gradient and HSF redistributed from nucleus to cytoplasm in the same spatiotemporal pattern. In a highly inbred derivative of the Samarkind strain, HSF moved into embryonic nuclei earlier than in our standard wild-type strain. Correspondingly, Hsp70 was inducible earlier, confirming that nuclear transport of HSF controls the inducibility of Hsp70 in early embryos. We also report for the first time the nuclear import patterns of two general transcription factors, RNA polymerase subunit Ilc and TATA binding protein (TBP). Both enter nuclei in a highly synchronous manner, independently of each other and of HSF. The import of TBP coincides with the first reported appearance of transcripts in the embryo. We suggest that the potentiation of general and heat shock-specific transcription in Drosophila embryos is controlled by the developmentally programmed relocalization of general and heat shock-specific transcription factors. Restricted nuclear entry of HSF represents a newly described mechanism for regulating the heat-shock response.

Dimethyl-sulfoxide is a Suitable Solvent for Fluorescent Microscopy Detection of Medium and Strong Heat Shock Inductors Using Transgenic Zebrafish

2018 ◽  
Vol 69 (2) ◽  
pp. 337-340
Author(s):  
Vlad Preluca ◽  
Bogdan Horatiu Serb ◽  
Sanda Marchian ◽  
Diter Atasie ◽  
Mihaela Cernusca Mitariu ◽  
...  
Keyword(s):  
Heat Shock ◽  
Dimethyl Sulfoxide ◽  
Heat Shock Response ◽  
Protein Misfolding ◽  
Fluorescent Microscopy ◽  
Screening Tests ◽  
Transgenic Zebrafish ◽  
Fluorescent Intensity ◽  
Shock Response ◽  
Heat Shock Induction

Heat shock inductors have potential as treatment for degenerative and protein misfolding diseases. Dimethyl-sulfoxide is widely used as a solvent in pharmacological screening tests and has been shown to have heat shock induction effects. Transgenic Tg (hsp70l:EGFP-HRAS_G12V)io3(AB) zebrafish larvae were exposed for 24 hours to dimethyl-sulfoxide in concentratios of 0.1-2%, and to moderate heat shock inductors pentoxifylline and tacrolimus. Positive controls were exposed to 35, 38 and 40�C for 20 min, and incubated for 24 h at 28�C. Heat shock response was measured by fluorescence microscopy and signal intensity quantification in FIJI. Dimethyl-sulfoxide caused a dose-dependant increase in fluorescent intensity, but significantly lower compared with exposure to 38 and 40�C. Pentoxifylline and tacrolimus induced a significantly higher increase in fluorescence compared with 0.5% dimethyl-sulfoxide. Thus, although dimethyl-sulfoxide has independent heat shock induction effects, concentrations of up to 0.5% are suitable for heat shock response screening tests.

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