Search Organism: All OrganismsArabidopsis thalianaBacillus subtilis 168Bos taurusCaenorhabditis elegansCanis familiarisDanio rerioDrosophila melanogasterEquus caballusEscherichia coli K12Gallus gallusHomo sapiensMacaca mulattaMus musculusNematostella vectensisOryza sativaPan troglodytesRattus norvegicusSaccharomyces cerevisiaeSchizosaccharomyces pombeStrongylocentrotus purpuratusTakifugu rubripesXenopus laevis home help / support contribute downloads mirrors about us Biochemistry Feb (2008); 47(7):1918-27 The C-terminal extension of Saccharomyces cerevisiae Hsp104 plays a role in oligomer assembly- Mackay RG, Helsen CW, Tkach JM, Glover JR Department of Biochemistry, University of Toronto, 1 King's College Circle, Toronto, Ontario, Canada M5S 1A8- Abstract: The Saccharomyces cerevisiae protein Hsp104, a member of the Hsp100-Clp AAA- family of ATPases, and its orthologues in plants -Hsp101- and bacteria -ClpB- function to disaggregate and refold thermally denatured proteins following heat shock and play important roles in thermotolerance- The primary sequences of fungal Hsp104's contain a largely acidic C-terminal extension not present in bacterial ClpB's- In this work, deletion mutants were used to determine the role this extension plays in Hsp104 structure and function- Elimination of the C-terminal tetrapeptide DDLD diminishes binding of the tetratricopeptide repeat domain cochaperone Cpr7 but is dispensable for Hsp104-mediated thermotolerance- The acidic region of the extension is also dispensable for thermotolerance and for the stimulation of Hsp104 ATPase activity by poly-l-lysine, but its truncation results in an oligomerization defect and reduced ATPase activity in vitro- Finally, sequence alignments reveal that the C-terminal extension contains a sequence -VLPNH- that is conserved in fungal Hsp104's but not in other orthologues- Hsp104 lacking the entire C-terminal extension including the VLPNH region does not assemble and has very low ATPase activity- In the presence of a molecular crowding agent the ATPase activities of mutants with longer truncations are partially restored possibly through enhanced oligomer formation- However, elimination of the whole C-terminal extension results in an Hsp104 molecule which is unable to assemble and becomes aggregation prone at high temperature, highlighting a novel structural role for this region- [PUBMED: 18197703] Copyright © 2009, Tyers Lab, The Samuel Lunenfeld Research Institute, Mount Sinai Hospital, All Rights Reserved. terms and conditions - privacy policy - Osprey Network Visualization System BioGRID: A General Repository for Interaction Datasets. Chris Stark, Bobby-Joe Breitkreutz, Teresa Reguly, Lorrie Boucher, Ashton Breitkreutz, Mike Tyers. Nucleic Acids Res. Jan 1;34:D535-9.