title: The M-domain controls Hsp104 protein remodeling activity in an Hsp70/Hsp40-dependent manner.
abstract: Yeast Hsp104 is a ring-forming ATP-dependent protein disaggregase that, together with the cognate Hsp70 chaperone system, has the remarkable ability to rescue stress-damaged proteins from a previously aggregated state. Both upstream and downstream functions for the Hsp70 system have been reported, but it remains unclear how Hsp70/Hsp40 is coupled to Hsp104 protein remodeling activity. Hsp104 is a multidomain protein that possesses an N-terminal domain, an M-domain, and two tandem AAA(+) domains. The M-domain forms an 85-A long coiled coil and is a hallmark of the Hsp104 chaperone family. While the three-dimensional structure of Hsp104 has been determined, the function of the M-domain is unclear. Here, we demonstrate that the M-domain is essential for protein disaggregation, but dispensable for Hsp104 ATPase- and substrate-translocating activities. Remarkably, replacing the Hsp104 M-domain with that of bacterial ClpB, and vice versa, switches species specificity so that our chimeras now cooperate with the noncognate Hsp70/DnaK chaperone system. Our results demonstrate that the M-domain controls Hsp104 protein remodeling activities in an Hsp70/Hsp40-dependent manner, which is required to unleash Hsp104 protein disaggregating activity.
authors.affiliation: Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, One Baylor Plaza, Houston, TX 77030, USA.
authors.forename: Bernhard
authors.initials: B
authors.lastname: Sielaff
authors.forename: Francis T F
authors.initials: FT
authors.lastname: Tsai
mesh_terms: D050956:HSP40 Heat-Shock Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D018840:HSP70 Heat-Shock Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D006360:Heat-Shock Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D006358:Hot Temperature; D006801:Humans; D008958:Models, Molecular; D055503:Protein Multimerization; D017434:Protein Structure, Tertiary; D029701:Saccharomyces cerevisiae Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D013045:Species Specificity
chemical_list: D050956:HSP40 Heat-Shock Proteins; D018840:HSP70 Heat-Shock Proteins; D006360:Heat-Shock Proteins; D029701:Saccharomyces cerevisiae Proteins; C070972:HsP104 protein, S cerevisiae