Unscrambling an egg: protein disaggregation by AAA+ proteins
AUTOR(ES)
Weibezahn, Jimena
FONTE
BioMed Central
RESUMO
A protein quality control system, consisting of molecular chaperones and proteases, controls the folding status of proteins and prevents the aggregation of misfolded proteins by either refolding or degrading aggregation-prone species. During severe stress conditions this protection system can be overwhelmed by high substrate load, resulting in the formation of protein aggregates. In such emergency situations, Hsp104/ClpB becomes a key player for cell survival, as it has the extraordinary capacity to rescue proteins from an aggregated state in cooperation with an Hsp70 chaperone system. The ring-forming Hsp104/ClpB chaperone belongs to the AAA+ protein superfamily, which in general drives the assembly and disassembly of protein complexes by ATP-dependent remodelling of protein substrates. A disaggregation activity was also recently attributed to other eubacterial AAA+ proteins, while such an activity has not yet been identified in mammalian cells. In this review, we report on new insights into the mechanism of protein disaggregation by AAA+ proteins, suggesting that these chaperones act as molecular crowbars or ratchets.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=324561Documentos Relacionados
- Nucleotide-dependent interactions between a fork junction–RNA polymerase complex and an AAA+ transcriptional activator protein
- Degrons in protein substrates program the speed and operating efficiency of the AAA+ Lon proteolytic machine
- DNA-protein binding assays from a single sea urchin egg: a high-sensitivity capillary electrophoresis method.
- Role of the processing pore of the ClpX AAA+ ATPase in the recognition and engagement of specific protein substrates
- Regulation of the transcriptional activator NtrC1: structural studies of the regulatory and AAA+ ATPase domains
