Current Research
Actin Cytoskeleton and Translation in Yeast
Ongoing work in my lab has focused on a role for the actin cytoskeleton in translation in yeast. One approach that we have taken is to study a collection of actin mutations in yeast for defects in translation. We found that some of these mutants show defects in translation by a number of different assays. For example, we showed that a yeast elongation factor involved in protein synthesis, eEF1A, binds and bundles yeast actin in vitro, and overexpression of eEF1A resulted in synthetic growth defects in a subset of yeast with actin mutations (Munshi et al., 2001. Genetics 157:1425-1436). Additionally, some yeast with actin mutations showed a reduction in the fidelity of translation, as assayed by nonsense suppression, and hypersensitivity to drugs that affect translation (Kandl et al., 2002. Mol Genet Genomics 268:10-18).
Perhaps the most interesting of these actin mutations is the cold-sensitive actin mutation, act1-122. This mutation shows a 6-fold increase in read through of a stop codon during translation and hypersensitivity to paromomycin, an inhibitor of translation. In an effort to identify proteins that interact with this mutant actin in translation, we screened for high copy suppressors of the paromomycin hypersensitive phenotype of the act1-122 mutation. This screen has identified potential suppressors of the act1-122 paramomycin hypersensitive phenotype. Future work will focus on studying the interaction between these suppressors and actin.
