Proteomic analysis reveals the direct recruitment of intrinsically disordered regions to stress granules in S. cerevisiae.

Stress granules (SGs) are stress-induced membraneless condensates that store non-translating mRNA and stalled translation initiation complexes. Although metazoan SGs are dynamic compartments where proteins can rapidly exchange with their surroundings, yeast SGs seem largely static. To gain a better understanding of yeast SGs, we identified proteins that sediment after heat shock using mass spectrometry. Proteins that sediment upon heat shock are biased toward a subset of abundant proteins that are significantly enriched in intrinsically disordered regions (IDRs). Heat-induced SG localization of over 80 proteins were confirmed using microscopy, including 32 proteins not previously known to localize to SGs. We found that several IDRs were sufficient to mediate SG recruitment. Moreover, the dynamic exchange of IDRs can be observed using fluorescence recovery after photobleaching, whereas other components remain immobile. Lastly, we showed that the IDR of the Ubp3 deubiquitinase was critical for yeast SG formation. This work shows that IDRs can be sufficient for SG incorporation, can remain dynamic in vitrified SGs, and can play an important role in cellular compartmentalization upon stress.This article has an associated First Person interview with the first author of the paper.

Fostering equity, diversity, and inclusion in large, first-year classes: Using reflective practice questions to promote universal design for learning in ecology and evolution lessons.

Instructors can deliberately design for equity, diversity, and inclusion, including for large first-year classes, and now instructors have added challenges given COVID-19. Our paper explores the question: How do we integrate equity, diversity, and inclusion and universal design for learning (UDL) into first-year, undergraduate ecology and evolution introductory lessons given the COVID-19 pandemic? Given the large field exploring equity, diversity, and inclusion, we chose to focus on developing reflective practice question rubrics for before, during, and after lessons to encourage UDL for instructors, teaching assistants, and learners. We conducted a focus group within our team and discussed ideas related to online learning, including related pitfalls and solutions. Lastly, we created a figure to illustrate ideas and end with a general discussion. Our reflective practice questions for UDL rubrics, figure, focus group, and discussion aim to increase positive action for equity, diversity, and inclusion in the classroom and beyond.

Selective aggregation of the splicing factor Hsh155 suppresses splicing upon genotoxic stress.

Upon genotoxic stress, dynamic relocalization events control DNA repair as well as alterations of the transcriptome and proteome, enabling stress recovery. How these events may influence one another is only partly known. Beginning with a cytological screen of genome stability proteins, we find that the splicing factor Hsh155 disassembles from its partners and localizes to both intranuclear and cytoplasmic protein quality control (PQC) aggregates under alkylation stress. Aggregate sequestration of Hsh155 occurs at nuclear and then cytoplasmic sites in a manner that is regulated by molecular chaperones and requires TORC1 activity signaling through the Sfp1 transcription factor. This dynamic behavior is associated with intron retention in ribosomal protein gene transcripts, a decrease in splicing efficiency, and more rapid recovery from stress. Collectively, our analyses suggest a model in which some proteins evicted from chromatin and undergoing transcriptional remodeling during stress are targeted to PQC sites to influence gene expression changes and facilitate stress recovery.