NDLI: The Hsc66-Hsc20 Chaperone System in Escherichia coli: Chaperone Activity and Interactions with the DnaK-DnaJ-GrpE System

Content Provider	PubMed Central
Author	Silberg, Jonathan J. Hoff, Kevin G. Vickery, Larry E.
Copyright Year	1998
Abstract	Hsc66, a stress-70 protein, and Hsc20, a J-type accessory protein, comprise a newly described Hsp70-type chaperone system in addition to DnaK-DnaJ-GrpE in Escherichia coli. Because endogenous substrates for the Hsc66-Hsc20 system have not yet been identified, we investigated chaperone-like activities of Hsc66 and Hsc20 by their ability to suppress aggregation of denatured model substrate proteins, such as rhodanese, citrate synthase, and luciferase. Hsc66 suppressed aggregation of rhodanese and citrate synthase, and ATP caused effects consistent with complex destabilization typical of other Hsp70-type chaperones. Differences in the activities of Hsc66 and DnaK, however, suggest that these chaperones have dissimilar substrate specificity profiles. Hsc20, unlike DnaJ, did not exhibit intrinsic chaperone activity and appears to function solely as a regulatory cochaperone protein for Hsc66. Possible interactions between the Hsc66-Hsc20 and DnaK-DnaJ-GrpE chaperone systems were also investigated by measuring the effects of cochaperone proteins on Hsp70 ATPase activities. The nucleotide exchange factor GrpE did not stimulate the ATPase activity of Hsc66 and thus appears to function specifically with DnaK. Cross-stimulation by the cochaperones Hsc20 and DnaJ was observed, but the requirement for supraphysiological concentrations makes it unlikely that these interactions occur significantly in vivo. Together these results suggest that Hsc66-Hsc20 and DnaK-DnaJ-GrpE comprise separate molecular chaperone systems with distinct, nonoverlapping cellular functions.
Starting Page	6617
File Format	PDF
ISSN	10985530
e-ISSN	10985530
Journal	Journal of Bacteriology
Issue Number	24
Volume Number	180
Language	English
Publisher	American Society for Microbiology
Publisher Date	1998-12-01
Access Restriction	Open
Rights Holder	American Society for Microbiology
Subject Keyword	Research in Higher Education
Content Type	Text
Resource Type	Article
Subject	Molecular Biology Microbiology

Sl.	Authority	Responsibilities	Communication Details
1	Ministry of Education (GoI), Department of Higher Education	Sanctioning Authority	https://www.education.gov.in/ict-initiatives
2	Indian Institute of Technology Kharagpur	Host Institute of the Project: The host institute of the project is responsible for providing infrastructure support and hosting the project	https://www.iitkgp.ac.in
3	National Digital Library of India Office, Indian Institute of Technology Kharagpur	The administrative and infrastructural headquarters of the project	Dr. B. Sutradhar bsutra@ndl.gov.in
4	Project PI / Joint PI	Principal Investigator and Joint Principal Investigators of the project	Dr. B. Sutradhar bsutra@ndl.gov.in Prof. Saswat Chakrabarti will be added soon
5	Website/Portal (Helpdesk)	Queries regarding NDLI and its services	support@ndl.gov.in
6	Contents and Copyright Issues	Queries related to content curation and copyright issues	content@ndl.gov.in
7	National Digital Library of India Club (NDLI Club)	Queries related to NDLI Club formation, support, user awareness program, seminar/symposium, collaboration, social media, promotion, and outreach	clubsupport@ndl.gov.in
8	Digital Preservation Centre (DPC)	Assistance with digitizing and archiving copyright-free printed books	dpc@ndl.gov.in
9	IDR Setup or Support	Queries related to establishment and support of Institutional Digital Repository (IDR) and IDR workshops	idr@ndl.gov.in

Involvement of the DnaK-DnaJ-GrpE chaperone team in protein secretion in Escherichia coli.

Hsc66 and Hsc20, a new heat shock cognate molecular chaperone system from Escherichia coli.

DnaK, DnaJ, and GrpE are required for flagellum synthesis in Escherichia coli.

Interaction of the iron–sulfur cluster assembly protein IscU with the Hsc66/Hsc20 molecular chaperone system of Escherichia coli

Both the Escherichia coli chaperone systems, GroEL/GroES and DnaK/DnaJ/GrpE, can reactivate heat-treated RNA polymerase. Different mechanisms for the same activity.

The DnaK Chaperone System of Escherichia coli: Quaternary Structures and Interactions of the DnaK and GrpE Components

Participation of Escherichia coli heat shock proteins DnaJ, DnaK, and GrpE in P1 plasmid replication.

Escherichia coli DnaJ and GrpE heat shock proteins jointly stimulate ATPase activity of DnaK.

The ATP hydrolysis-dependent reaction cycle of the Escherichia coli Hsp70 system DnaK, DnaJ, and GrpE.

The Hsc66-Hsc20 Chaperone System in Escherichia coli: Chaperone Activity and Interactions with the DnaK-DnaJ-GrpE System

Similar Documents

Involvement of the DnaK-DnaJ-GrpE chaperone team in protein secretion in Escherichia coli.

Hsc66 and Hsc20, a new heat shock cognate molecular chaperone system from Escherichia coli.

DnaK, DnaJ, and GrpE are required for flagellum synthesis in Escherichia coli.

Interaction of the iron–sulfur cluster assembly protein IscU with the Hsc66/Hsc20 molecular chaperone system of Escherichia coli

Both the Escherichia coli chaperone systems, GroEL/GroES and DnaK/DnaJ/GrpE, can reactivate heat-treated RNA polymerase. Different mechanisms for the same activity.

The DnaK Chaperone System of Escherichia coli: Quaternary Structures and Interactions of the DnaK and GrpE Components

Participation of Escherichia coli heat shock proteins DnaJ, DnaK, and GrpE in P1 plasmid replication.

Escherichia coli DnaJ and GrpE heat shock proteins jointly stimulate ATPase activity of DnaK.

The ATP hydrolysis-dependent reaction cycle of the Escherichia coli Hsp70 system DnaK, DnaJ, and GrpE.

The Hsc66-Hsc20 Chaperone System in Escherichia coli: Chaperone Activity and Interactions with the DnaK-DnaJ-GrpE System