Reversion of protein aggregation mediated by Sso7d in cell extracts of Sulfolobus solfataricus.
In eukaryotic cells and in Escherichia coli, reversion of protein aggregation is mediated by the network of chaperones belonging to Hsp70 and Hsp100 families [Weibezahn, Bukau and Mogk (2004) Microb. Cell Fact. 3, 1-12]. The thermophilic prokaryotes of the archaea domain lack homologues of these chaperone families, and the mechanisms they use to rescue aggregated proteins are unknown [Macario, Malz and Conway de Macario (2004) Front. Biosci. 9, 1318-1332]. In the present study, we show that stable protein aggregates can be detected in extracts of starved cells of the thermophilic archaeon Sulfolobus solfataricus, and that the protein Sso7d interacts with the aggregates and mediates the disassembly of the aggregates and the re-activation of insolubilized beta-glycosidase in the presence of ATP hydrolysis. Furthermore, we report that heat-induced protein aggregates in extracts of exponential cells of S. solfataricus contain Sso7d that rescues insolubilized proteins in the presence of ATP hydrolysis. Results of these experiments performed in cell extracts are consistent with an in vivo role of Sso7d in reverting protein aggregation.
Guagliardi
Annamaria
A
Dipartimento di Chimica Biologica, Università Federico II di Napoli, Via Mezzocannone 16, 80134 Napoli, Italy. guaglia@unina.it
Mancusi
Lucia
L
Rossi
Mosè
M
D000255:Adenosine Triphosphate / Q000378:metabolism; D019843:Archaeal Proteins / Q000378:metabolism*; D004268:DNA-Binding Proteins / Q000378:metabolism*; D004789:Enzyme Activation; D005959:Glucosidases / Q000378:metabolism; D006358:Hot Temperature; D006868:Hydrolysis; D018832:Molecular Chaperones / Q000378:metabolism; D012995:Solubility; D016944:Sulfolobus / Q000737:chemistry* / Q000254:growth & development
D019843:Archaeal Proteins; D004268:DNA-Binding Proteins; D018832:Molecular Chaperones; C093228:Sso7d protein, Sulfolobus; D000255:Adenosine Triphosphate; D005959:Glucosidases; C104851:Sulfolobus solfataricus beta-glycosidase