Abstract:
:The molecular chaperone Hsp90 has been found ubiquitously as a predominantly cytoplasmic dimer. By interacting with cytoplasmic or nuclear proteins such as pp60v-src or steroid receptors, Hsp90 helps its targets to become competent for full biological activity. Mutational deletion analysis of some properties of chicken Hsp90 alpha was undertaken after transient transfection of the constructs in COS7 cells. First, Hsp90 mutants were analyzed for their ability to behave as cytosolic dimers. We confirmed that the C-terminal Hsp90 region (amino acids 446-728) was sufficient for dimerization, and found that deletion of three small subregions in the 200 C-terminal residues precluded Hsp90 dimer formation. Moreover, we demonstrated that the N-terminal region of the protein (1-442) was not involved in dimerization. Second, the subcellular localization of the wild-type (WT) protein and mutants was analyzed by specific immunodetection and confocal microscopy. Most of the mutants were cytoplasmic like Hsp90WT, a nuclear localization being barely detectable in the WT protein or in mutants with a C-terminal truncation equal to or shorter than 286 residues. Surprisingly a mutant encoding the N-terminal region (1-285) was nuclear localized. In addition, the in vivo interaction between the cytoplasmic Hsp90 and the nuclear ER was documented after coexpression of both proteins in the same cells: some Hsp90 was shifted into the nucleus via its interaction with ER. From an analysis of dimeric or monomeric cytoplasmic Hsp90 mutants, we found that disruption of Hsp90 dimer did not systematically impede its interaction with ER. Finally, Hsp90WT and cytoplasmic mutants were tested for their ability to rescue from lethality a yeast strain deleted of both Hsp90 genes. Interestingly, the delta 661-677 mutant that showed an impaired dimerization but interacted with ER was able to confer viability, while the mutant deleted of the 30 C-terminal residues (NC6) was monomeric, did not confer viability and did not interact with ER. We therefore suggest that Hsp90 properties analyzed here are not necessarily interdependent.
journal_name
J Cell Scijournal_title
Journal of cell scienceauthors
Meng X,Devin J,Sullivan WP,Toft D,Baulieu EE,Catelli MGsubject
Has Abstractpub_date
1996-07-01 00:00:00pages
1677-87eissn
0021-9533issn
1477-9137journal_volume
109 ( Pt 7)pub_type
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journal_title:Journal of cell science
pub_type: 杂志文章
doi:10.1242/jcs.00393
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journal_title:Journal of cell science
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pub_type: 杂志文章
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journal_title:Journal of cell science
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更新日期:1980-10-01 00:00:00
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journal_title:Journal of cell science
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更新日期:1991-09-01 00:00:00
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journal_title:Journal of cell science
pub_type: 杂志文章
doi:10.1242/jcs.jcs124404
更新日期:2013-05-01 00:00:00
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journal_title:Journal of cell science
pub_type: 杂志文章
doi:10.1242/jcs.031088
更新日期:2008-06-15 00:00:00
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journal_title:Journal of cell science
pub_type: 杂志文章
doi:
更新日期:1990-05-01 00:00:00
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journal_title:Journal of cell science
pub_type: 杂志文章,评审
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更新日期:2014-09-01 00:00:00
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journal_title:Journal of cell science
pub_type: 杂志文章
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更新日期:2015-07-01 00:00:00
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journal_title:Journal of cell science
pub_type: 杂志文章
doi:
更新日期:1987-03-01 00:00:00
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journal_title:Journal of cell science
pub_type: 杂志文章
doi:10.1242/jcs.01631
更新日期:2005-01-01 00:00:00
abstract::Host/symbiont specificity has been investigated in non-symbiotic and aposymbiotic brown and green hydra infected with various free-living and symbiotic species and strains of Chlorella and Chlorococcum. Morphology and ultrastructure of the symbioses obtained have been compared. Aposymbiotic Swiss Hydra viridis and Jap...
journal_title:Journal of cell science
pub_type: 杂志文章
doi:
更新日期:1986-12-01 00:00:00
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journal_title:Journal of cell science
pub_type: 杂志文章
doi:
更新日期:1996-05-01 00:00:00
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journal_title:Journal of cell science
pub_type: 杂志文章
doi:10.1242/jcs.01419
更新日期:2004-10-15 00:00:00
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journal_title:Journal of cell science
pub_type: 杂志文章
doi:
更新日期:1994-10-01 00:00:00
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journal_title:Journal of cell science
pub_type: 杂志文章,评审
doi:10.1242/jcs.216259
更新日期:2018-08-03 00:00:00
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journal_title:Journal of cell science
pub_type: 杂志文章,评审
doi:10.1242/jcs.199570
更新日期:2017-07-15 00:00:00
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journal_title:Journal of cell science
pub_type: 杂志文章
doi:
更新日期:1998-10-01 00:00:00
abstract::Chromatin is no longer considered to be a static structural framework for packaging DNA within the nucleus but is instead believed to be an interactive component of DNA metabolism. The ordered assembly of chromatin produces a nucleoprotein template capable of epigenetically regulating the expression and maintenance of...
journal_title:Journal of cell science
pub_type: 杂志文章,评审
doi:
更新日期:2000-08-01 00:00:00
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journal_title:Journal of cell science
pub_type: 杂志文章
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更新日期:2019-05-02 00:00:00
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journal_title:Journal of cell science
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更新日期:2017-06-01 00:00:00
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journal_title:Journal of cell science
pub_type: 杂志文章
doi:
更新日期:1986-03-01 00:00:00
abstract::Although the 11.5 kDa Zn(2+)-binding protein (ZnBP, parathymosin-alpha) possesses a functional bipartite nuclear localization signal it was found in most tissues in the cytoplasm. The cultivation of freshly isolated rat hepatocytes for 24 hours under standard conditions was associated with an almost complete transloca...
journal_title:Journal of cell science
pub_type: 杂志文章
doi:
更新日期:1999-11-01 00:00:00
abstract::ABCG2 belongs to the ATP-binding cassette superfamily of transmembrane proteins and is ubiquitously expressed in stem cells including those in the developing nervous system. The ability of ABCG2 to preferentially exclude DNA-intercalating dyes is regarded to be the basis for the enrichment of stem cells or progenitors...
journal_title:Journal of cell science
pub_type: 杂志文章
doi:10.1242/jcs.008417
更新日期:2007-08-01 00:00:00
abstract::Dishevelled-3 (Dvl3) is a multivalent scaffold protein that is essential to Wnt signaling during development. Although Dvl-based punctae have been visualized by fluorescence microscopy; the physical nature and dynamic character of the such complexes are enigmatic. We use steric-exclusion chromatography, affinity pull-...
journal_title:Journal of cell science
pub_type: 杂志文章
doi:10.1242/jcs.075275
更新日期:2010-11-01 00:00:00
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journal_title:Journal of cell science
pub_type: 杂志文章
doi:10.1242/jcs.113019
更新日期:2012-12-15 00:00:00
abstract::Removal of interleukin-3 from murine IC.DP pre-mast cells results in irreversible commitment to apoptosis within 18 hours. To identify early events necessary for the engagement of apoptosis we examined the regulation of intracellular pH (pH(i)). IC.DP cells acidified 2 hours after removal of interleukin-3 (before disc...
journal_title:Journal of cell science
pub_type: 杂志文章
doi:
更新日期:1997-02-01 00:00:00
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journal_title:Journal of cell science
pub_type: 杂志文章
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