Dataset Information

The isoforms of the molecular chaperone Hsp90 from S. cerevisiae differ in structure, function and client range

ABSTRACT: The molecular chaperone Hsp90 is an important regulator of proteostasis. It has remained unclear why S. cerevisiae possesses two Hsp90 isoforms, the constitutively expressed Hsc82 and the stress-inducible Hsp82. Here, we report distinct differences despite a sequence identity of 97 %. Consistent with its function under stress conditions, Hsp82 is more stable and refolds more efficiently than Hsc82. Hspc82 and Hsc82 also differ in their ATPases and conformational cycles. Hsc82 is more processive and populates closed states to a greater extent. Variations in the N-terminal ATP-binding domain modulate its dynamics and conformational cycle. Despite these differences, the client interactomes, are largely identical, but isoform-specific interactors exist both under physiological conditions and heat shock. Taken together, changes mainly in the N-domain create a stress-specific, more resilient protein with a shifted activity profile. Thus, the precise tuning of the Hsp90 isoforms preserves the basic mechanism but adapts it to specific needs

INSTRUMENT(S): Q Exactive Plus

ORGANISM(S): Saccharomyces Cerevisiae (baker's Yeast)

SUBMITTER: Frank Stein

LAB HEAD: Johannes Buchner

PROVIDER: PXD013955 | Pride | 2019-08-12

REPOSITORIES: Pride

ACCESS DATA

Publications

The Hsp90 isoforms from S. cerevisiae differ in structure, function and client range.

Girstmair Hannah H Tippel Franziska F Lopez Abraham A Tych Katarzyna K Stein Frank F Haberkant Per P Schmid Philipp Werner Norbert PWN Helm Dominic D Rief Matthias M Sattler Michael M Buchner Johannes J

Nature communications 20190809 1

The molecular chaperone Hsp90 is an important regulator of proteostasis. It has remained unclear why S. cerevisiae possesses two Hsp90 isoforms, the constitutively expressed Hsc82 and the stress-inducible Hsp82. Here, we report distinct differences despite a sequence identity of 97%. Consistent with its function under stress conditions, Hsp82 is more stable and refolds more efficiently than Hsc82. The two isoforms also differ in their ATPases and conformational cycles. Hsc82 is more processive a ...[more]

PMID: 31399574

Similar Datasets

Project description:The zinc uptake regulator Zur is a Zn2+-sensing metalloregulatory protein involved in the maintenance of bacterial zinc homeostasis. Up to now, regulation of zinc homeostasis by Zur is poorly understood in Y. pestis. We constructed a zur null mutant of Y. pestis biovar microtus strain 201. Microarray expression analysis disclosed a set of 154 Zur-dependent genes of Y. pestis under zinc rich condition. Real-time reverse transcription (RT)-PCR was subsequently used to validate the microarray data. Based on the 154 Zur-dependent genes, predicted regulatory Zur motifs were used to screen for potential direct Zur targets including three putative operons znuA, znuCB and ykgM-RpmJ2. The LacZ reporter fusion analysis verified that Zur greatly repressed the promoter activity of the above three operons. The subsequent electrophoretic mobility shift assay (EMSA) demonstrated that a purified Zur protein was able to bind to the promoter regions of the above three operons. The DNase I footprinting was used to identify the Zur binding sites for the above three operons, verifying the Zur box sequence as predicted previously in Î³-Proteobacteria. The primer extension assay was further used to determine the transcription start sites for the above three operons and to localize the -10 and -35 elements. Zur binding sites overlapped the -10 sequence of its target promoters, which was consistent with the previous observation that Zur binding would block the entry of the RNA polymerase to repress the transcription of its target genes. Zur as a repressor directly controls the transcription of znuA, znuCB and ykgM-RpmJ2 in Y. pestis by employing a conserved mechanism of Zur-promoter DNA association as observed in Î³-Proteobacteria. Zur contributes to zinc homeostasis in Y. pestis likely through transcriptional repression of the high-affinity zinc uptake system ZnuACB and two alternative ribosomal proteins YkgM and RpmJ2. The wild-type (WT) Y. pestis strain 201 belongs to a newly established Y. pestis biovar, Microtus, which was thought to be avirulent to humans, but highly virulent to mice. An in-frame deletion of the zur gene was constructed by using one step inactivation method based on the lambda phage recombination in which PCR primers provide the homology to the target gene, as described previously by Datsenko and Wanner. The entire coding region of zur was replaced by a kanamycin resistance (KnR) cassette, which was verified by PCR and DNA sequencing. The resulting mutant strain was referred to as Îzur. Both the WT strain and the Zur mutant were pre-cultivated at 26 ÂºC to the middle exponential growth phase (OD620 about 1.0) in TMH medium. The cell cultures were then diluted 1:20 in fresh TMH medium and grown at 26Â°C until an OD620 of about 1.0. Finally, 5mM ZnCl2 was added into each cell culture to ensure zinc rich conditions. Growth was continued for 30 min at 26Â°C before harvested for total RNA isolation. Gene expression profiles were compared between WT and Îzur. RNA samples were isolated from four individual bacterial cultures, as biological replicates, for each strain. The dual-fluorescently (Cy3 or Cy5 dye) labeled cDNA probes, for which the incorporated dye was reversed, were synthesized from the RNA samples, and then hybridized to four separated microarray slides, respectively.

Dataset Information

The isoforms of the molecular chaperone Hsp90 from S. cerevisiae differ in structure, function and client range

Publications

The Hsp90 isoforms from S. cerevisiae differ in structure, function and client range.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure