Geisterfer Zachary M, Jalihal Ameya P, Cole Sierra J, Gladfelter Amy S
Department of Cell Biology, Duke University, Durham, NC 27710.
Department of Biochemistry and Biophysics, UNC Chapel Hill, NC 27517.
bioRxiv. 2024 Dec 17:2024.12.12.628219. doi: 10.1101/2024.12.12.628219.
Coordination between growth and division is a fundamental feature of cells. In many syncytia, cell growth must couple with multiple nuclear divisions in one cytoplasm. In the fungus, , cell-cycle progression and hyphal elongation require condensates formed by the protein Whi3 in complex with distinct mRNA species. We hypothesized the condensates may act through local translation regulation and find that Whi3 target mRNAs show distinct spatial biases in translation in vivo. Whi3-RNA condensates can both promote and repress RNA translation in an RNA- and condensate size-dependent manner in vitro. Interestingly, we observe a sub-condensate enrichment of translation that is tunable by RNA valency and protein phospho-state. Together, these data suggest that Whi3 condensates generate a continuum of translation states, resulting in asynchronous nuclear divisions coordinated with growth. This local regulation requires a minimal complement of molecular components at the nano scale to support global coordination at the cell scale.
生长与分裂之间的协调是细胞的一个基本特征。在许多合胞体中,细胞生长必须与一个细胞质中的多个核分裂相耦合。在真菌中,细胞周期进程和菌丝伸长需要由蛋白质Whi3与不同的mRNA种类形成的凝聚物。我们推测这些凝聚物可能通过局部翻译调控发挥作用,并发现Whi3靶标mRNA在体内翻译中表现出不同的空间偏向性。Whi3-RNA凝聚物在体外能以RNA和凝聚物大小依赖的方式促进和抑制RNA翻译。有趣的是,我们观察到翻译的亚凝聚物富集可由RNA价态和蛋白质磷酸化状态调节。总之,这些数据表明Whi3凝聚物产生了一个连续的翻译状态,导致与生长协调的异步核分裂。这种局部调控需要纳米尺度上最少的分子成分补充,以支持细胞尺度上的全局协调。