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bioRxiv · 10.1101/2024.01.09.574866

Rim4 is a Meiotic Thermal Sensor and Drives Biogenesis of Stress Granules

Zhang, R.·Li, S.·Feng, W.·Qian, S.·Chellappa, A. J.·Wang, F.
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Abstract

Rim4 is a meiosis-specific RNA-binding protein (RBP) that sequesters mRNAs to suppress their translation. Previous work has defined the Rim4 C-terminal low-complexity domain (LCD) as sequences that form self-propagating amyloid-like aggregates. Here, we uncovered a dynamic and reversible form of Rim4 self-assembly primarily triggered by heat during meiosis, proportionally from 30{degrees}C to 42{degrees}C. The formed thermal Rim4 condensates in cell promptly stimulates stress granule (SG) assembly, recruiting SG-resident proteins, such as Pab1 and Pbp1, and strikingly, decreases the required temperature for meiotic SG formation ([~]33{degrees}C) by [~]9{degrees}C as compared to mitosis ([~]42{degrees}C). This sensitization of meiotic SG formation to heat effectively prevents meiosis progression and sporulation under harmful thermal turbulence. Meanwhile, the Rim4-positive meiotic SGs protect Rim4 and Rim4-sequestered mRNAs from autophagy to allow a rapid recovery from stalled meiosis upon the stress relief. Mechanistically, we found that the yeast 14-3-3 proteins (Bmh1 and Bmh2) and nucleic acids brake initiation of heat-induced Rim4 self-assembly, and Hsp104 facilitates the restoration of intracellular Rim4 distribution during the recovery.

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Zhang, R., Li, S., Feng, W., Qian, S., Chellappa, A. J., Wang, F.. 2024-01-11. Rim4 is a Meiotic Thermal Sensor and Drives Biogenesis of Stress Granules. https://doi.org/10.1101/2024.01.09.574866

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