Polymerase eta is a short-lived, proteasomally degraded protein that is temporarily stabilized following UV irradiation in Saccharomyces cerevisiae.

Saccharomyces cerevisiae Rad30 is the homolog of human DNA polymerase eta whose inactivation leads to the cancer-prone syndrome xeroderma pigmentosum variant. Both human and yeast polymerase eta are responsible for error-free bypass of UV-induced cis-syn pyrimidine dimers and several other DNA lesions. Here we show, using yeast strains expressing TAP-tagged Rad30, that the level of this protein is post-translationally regulated via ubiquitination and proteasome-mediated degradation.

The influence of the mismatch-repair system on stationary-phase mutagenesis in the yeast Saccharomyces cerevisiae.

Stationary-phase (also called adaptive) mutation occurs in non-dividing cells during prolonged non-lethal selective pressure, e.g. starvation for an essential amino acid.