title: The complexity of chloroplast chaperonins.
abstract: Type I chaperonins are large oligomeric protein ensembles that are involved in the folding and assembly of other proteins. Chloroplast chaperonins and co-chaperonins exist in multiple copies of two distinct isoforms that can combine to form a range of labile oligomeric structures. This complex system increases the potential number of chaperonin substrates and possibilities for regulation. The incorporation of unique subunits into the oligomer can modify substrate specificity. Some subunits are upregulated in response to heat shock and some show organ-specific expression, whereas others possess additional functions that are unrelated to their role in protein folding. Accumulating evidence suggests that specific subunits have distinct roles in biogenesis of ribulose-1,5-bisphosphate carboxylase oxygenase (Rubisco).
authors.affiliation: The George S. Wise Faculty of Life Sciences, Department of Biochemistry and Molecular Biology, Tel Aviv University, Ramat Aviv, Israel.
authors.forename: Anna
authors.initials: A
authors.lastname: Vitlin Gruber
authors.forename: Shahar
authors.initials: S
authors.lastname: Nisemblat
authors.forename: Abdussalam
authors.initials: A
authors.lastname: Azem
authors.forename: Celeste
authors.initials: C
authors.lastname: Weiss
mesh_terms: D017360:Arabidopsis / Q000378:metabolism; D060365:Chloroplast Proteins / Q000737:chemistry / Q000378:metabolism; D002736:Chloroplasts / Q000737:chemistry / Q000378:metabolism; D056384:Group I Chaperonins / Q000737:chemistry / Q000378:metabolism*; D005810:Multigene Family; D010944:Plants / Q000378:metabolism*; D017510:Protein Folding; D020033:Protein Isoforms; D021122:Protein Subunits; D012273:Ribulose-Bisphosphate Carboxylase / Q000737:chemistry / Q000378:metabolism*; D013379:Substrate Specificity
chemical_list: D060365:Chloroplast Proteins; D020033:Protein Isoforms; D021122:Protein Subunits; D056384:Group I Chaperonins; D012273:Ribulose-Bisphosphate Carboxylase
keywords: Rubisco; chaperone; chaperonin; chloroplast; protein folding