| Description |
This paper examines how stress granule (SG) formation and protein colocalization change in spinocerebellar ataxia type 2 (SCA2) compared to wild type (WT) cells. SCA2 is a neurodegenerative disease characterized by an Ataxin-2 mutation. Ataxin-2 has been shown to colocalize with Staufen1 in SGs, which are involved in post-transcriptional control of gene expression, but it is unknown how SG formation differs in SCA2 over WT cells. Initial experiments with heat shock showed that SG formation increases in SCA2 over WT cells. We therefore hypothesized that Ataxin-2 and Staufen1 colocalization in SGs would also be greater in SCA2 over WT cells. We chemically stressed patient fibroblasts with arsenite before fixing, staining, and imaging the cells. Using ImageJ, we counted the colocalized SGs and examined their size. We found increased colocalization of Ataxin-2 with Staufen1 in SCA2 over WT cells. We also found the colocalized SGs were on average larger in SCA2 over WT cells. The increased number of SGs may be because the deformed Ataxin-2 interacts with the SGs to bind them together more strongly, thus impeding SG disassembly. The increased colocalization of Ataxin-2 and Staufen1 in SGs may be a result the increased quantity of Staufen1 in SCA2 cells. These findings have broadened our understanding of how the Ataxin-2 mutation affects cellular homeostasis and identified novel areas for further research. Future research will explore why more SGs are formed in SCA2 over WT cells and if these results match what occurs in Purkinje cells, the cells most affected by SCA2. |
