[SWI], the prion formed by the chromatin remodeling factor Swi1, is highly sensitive to alterations in Hsp70 chaperone system activity
View abstract on PubMed
Summary
This summary is machine-generated.The yeast prion [SWI+] relies on Hsp70 chaperones for propagation, with Ydj1 being uniquely required. Overexpression of specific chaperone domains destabilizes this prion, suggesting a regulatory role in maintaining phenotypic diversity.
Area Of Science
- Molecular Biology
- Genetics
- Biochemistry
Background
- The yeast prion [SWI+] involves heritable amyloid aggregates of Swi1 protein, leading to partial loss of function in the SWI/SNF chromatin-remodeling complex.
- The SWI/SNF complex regulates numerous genes, impacting cellular functions.
- Hsp70 molecular chaperone systems are crucial for protein homeostasis and prion propagation.
Purpose Of The Study
- To investigate the specific roles of Hsp70 molecular chaperones and their co-chaperones in the propagation of the yeast prion [SWI+].
- To determine the impact of J-protein and Hsp110 family members on [SWI+] stability.
- To explore the regulatory mechanisms underlying [SWI+] stability and its potential role in cellular adaptation.
Main Methods
- Genetic analysis of [SWI+] propagation in yeast.
- Investigating the requirement for specific Hsp70 system components, including J-proteins (Sis1, Ydj1, Apj1) and nucleotide exchange factors (Sse1/2).
- Assessing the effect of overexpressing specific chaperone domains (J-domain) and nucleotide exchange factors on prion loss.
Main Results
- [SWI+] propagation is dependent on Hsp70 (Ssa), J-proteins (Sis1, Ydj1), and Hsp110s (Sse1/2).
- Unlike other yeast prions, [SWI+] specifically requires the J-protein Ydj1, although Apj1 can substitute.
- Overexpression of Ydj1's J-domain, or Sse nucleotide exchange factors, destabilizes and leads to the loss of [SWI+].
Conclusions
- The yeast prion [SWI+] exhibits unique dependencies on specific Hsp70 chaperone components, particularly Ydj1.
- The sensitivity of [SWI+] to overexpression of J-domains and Sse factors suggests a meta-stable state regulated by chaperone activity.
- This chaperone-mediated regulation may allow for phenotypic diversity, aiding cellular adaptation to environmental stress.