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Protein & Peptide Letters
ISSN (Print): 0929-8665
ISSN (Online): 1875-5305
DOI: 10.2174/092986606777790593      Price:  $58

Heat Shock Proteins, Substrate Specificity and Modulation of Function

Author(s): Yusuf Tutar
Pages 699-705 (7)
Hsp70 is a universally conserved essential protein chaperone. In addition to its roles in many cellular process, Hsp70 protects cells from stress by binding partially unfolded proteins. Therefore, Hsp70 prevents protein aggregation and prion formation. Prions are infectious agents and are responsible for several fatal neurodegenerative diseases. Eukaryotic cells have several cytosolic Hsp70 isoforms, some constitutively expressed (Hsc70s), and others expressed only when cells are exposed to stress (Hsp70s). To determine which factors conferred functional specificity, we constructed hybrid Hsc/Hsp chaperones. All hybrids supported growth except those that contained the ATPase domain derived from inducible Hsp70. Thus, regulation of peptide binding by ATP hydrolysis must differ significantly between Hsc- and Hsp70 isoforms. In this work, nucleotide and peptide binding domain communication of Hsp70 proteins during their interaction with nucleotides and peptide substrates were investigated in vitro by using hybrid constructs.
Hsp (Heat shock protein), co-chaperon (Hsp40; Ydj1 and Sis1)
Chemistry Department, Faculty of Science, Cumhuriyet University, Sivas 58140, Turkey.