Regulation of the heat shock conjugate Hsc70 in the mammalian cell: the characterization of the anti-apoptotic protein BAG-1 provides novel insights.

Abstract

The regulation of the chaperone activity of the heat shock cognate Hsc70 protein in the mammalian cell involves a cooperation with chaperone cofactors such as Hsp40, the Hsp70-interacting protein Hip, and the Hsc70/Hsp90-organizing protein Hop. Recent studies have now added another component to the list of Hsc70 cofactors, the BAG-1 protein. Initially identified as an anti-apoptotic molecule and binding partner of the cell death inhibitor Bcl-2, BAG-1 appears to fulfill its cellular function through a modulation of Hsc70's chaperone activity. BAG-1 acts as a nucleotide exchange factor in the Hsc70 ATPase cycle, thereby competing with the cofactor Hip which stabilizes the ADP-bound state of Hsc70. The functional characterization of BAG-1 thus reveals an unexpected versatility in the regulation of Hsc70 and appears to provide a link between apoptosis and the cellular chaperone machinery.

• Authors: J Höhfeld
• Journal: Biological chemistry (Biol Chem) Vol. 379 Issue 3 Pg. 269-74 (Mar 1998) ISSN: 1431-6730 [Print] Germany
• PMID: 9563821 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't, Review)

Chemical References

• BCL2-associated athanogene 1 protein
• Carrier Proteins
• DNA-Binding Proteins
• HSC70 Heat-Shock Proteins
• HSP70 Heat-Shock Proteins
• Transcription Factors
• Ubiquitins
• Adenosine Triphosphatases

Topics

• Adenosine Triphosphatases (metabolism)
• Amino Acid Sequence
• Animals
• Apoptosis
• Carrier Proteins (chemistry, metabolism)
• DNA-Binding Proteins
• HSC70 Heat-Shock Proteins
• HSP70 Heat-Shock Proteins
• Mammals
• Molecular Sequence Data
• Sequence Homology, Amino Acid
• Transcription Factors
• Ubiquitins (chemistry, metabolism)