GONUTS has been updated to MW1.31 Most things seem to be working but be sure to report problems.
PMID:22970306
| Citation |
Cohen, A, Ross, L, Nachman, I and Bar-Nun, S (2012) Aggregation of polyQ proteins is increased upon yeast aging and affected by Sir2 and Hsf1: novel quantitative biochemical and microscopic assays. PLoS ONE 7:e44785 |
|---|---|
| Abstract |
Aging-related neurodegenerative disorders, such as Parkinson's, Alzheimer's and Huntington's diseases, are characterized by accumulation of protein aggregates in distinct neuronal cells that eventually die. In Huntington's disease, the protein huntingtin forms aggregates, and the age of disease onset is inversely correlated to the length of the protein's poly-glutamine tract. Using quantitative assays to estimate microscopically and capture biochemically protein aggregates, here we study in Saccharomyces cerevisiae aging-related aggregation of GFP-tagged, huntingtin-derived proteins with different polyQ lengths. We find that the short 25Q protein never aggregates whereas the long 103Q version always aggregates. However, the mid-size 47Q protein is soluble in young logarithmically growing yeast but aggregates as the yeast cells enter the stationary phase and age, allowing us to plot an "aggregation timeline". This aging-dependent aggregation was associated with increased cytotoxicity. We also show that two aging-related genes, SIR2 and HSF1, affect aggregation of the polyQ proteins. In Δsir2 strain the aging-dependent aggregation of the 47Q protein is aggravated, while overexpression of the transcription factor Hsf1 attenuates aggregation. Thus, the mid-size 47Q protein and our quantitative aggregation assays provide valuable tools to unravel the roles of genes and environmental conditions that affect aging-related aggregation. |
| Links |
PubMed PMC3435303 Online version:10.1371/journal.pone.0044785 |
| Keywords |
Blotting, Western; DNA-Binding Proteins/metabolism; DNA-Binding Proteins/physiology; Heat-Shock Proteins/metabolism; Heat-Shock Proteins/physiology; Microscopy, Fluorescence; Peptides/metabolism; Saccharomyces cerevisiae/cytology; Saccharomyces cerevisiae/physiology; Saccharomyces cerevisiae Proteins/metabolism; Saccharomyces cerevisiae Proteins/physiology; Silent Information Regulator Proteins, Saccharomyces cerevisiae/metabolism; Silent Information Regulator Proteins, Saccharomyces cerevisiae/physiology; Sirtuin 2/metabolism; Sirtuin 2/physiology; Transcription Factors/metabolism; Transcription Factors/physiology |
| edit table |
Significance
Annotations
| Gene product | Qualifier | GO Term | Evidence Code | with/from | Aspect | Extension | Notes | Status |
|---|---|---|---|---|---|---|---|---|
| GO:1900036: positive regulation of cellular response to heat |
ECO:0000315: |
P |
Deletion of Sir2 in a wild-type yeast positively regulates the HSF1 trimerizing and binding to HSE1. The positive regulation of HSF1 increases the amount of poly-glutamine CAG repeats seen in proteins. In Figure 1, a SDS-PAGE gel resolved with cell lysates from cultures that underwent heat-shock combined immunobloting with a mouse anti-flag antibody for the different poly-Q protein segments. |
complete | ||||
See also
References
See Help:References for how to manage references in GONUTS.
