Physiological UPR induction drives gametogenesis through coordination of protein synthesis and ER structure

We previously found that the UPR is activated during meiosis in budding yeast, and here we investigate its role. We find that endogenous UPR activation during the meiotic divisions does not lead to a broad transcriptional program as reported for drug-triggered UPR activation and is dispensable for gamete formation.

In contrast, we find that the endogenous UPR activation that occurs just prior to meiosis is required for meiotic entry and thus gamete production. Only a small subset of known UPR transcriptional targets are part of this response, and the role of the pre-meiotic UPR can be replaced by increasing ER chaperone levels, reducing bulk translation, or reducing expression of the translocation factor Sec61. Together, these findings indicate that physiological meiosis-associated UPR activation supports normal proteostasis in multiple ways to prepare cells for meiotic entry, including by reducing expression of translation factors.