Departamento de Biología Experimental-Genética; Universidad de Jaén, Paraje de las Lagunillas, s/n, E-23071. Jaén, Spain.
Instituto de Biología Funcional y Genómica (IBFG), CSIC-USAL, Salamanca, Spain.
Nucleic Acids Res. 2024 Jul 8;52(12):7081-7095. doi: 10.1093/nar/gkae414.
Bud27 is a prefoldin-like protein that participates in transcriptional regulation mediated by the three RNA polymerases in Saccharomyces cerevisiae. Lack of Bud27 significantly affects RNA pol III transcription, although the involved mechanisms have not been characterized. Here, we show that Bud27 regulates the phosphorylation state of the RNA pol III transcriptional repressor, Maf1, influences its nuclear localization, and likely its activity. We demonstrate that Bud27 is associated with the Maf1 main phosphatase PP4 in vivo, and that this interaction is required for proper Maf1 dephosphorylation. Lack of Bud27 decreases the interaction among PP4 and Maf1, Maf1 dephosphorylation, and its nuclear entry. Our data uncover a new nuclear function of Bud27, identify PP4 as a novel Bud27 interactor and demonstrate the effect of this prefoldin-like protein on the posttranslational regulation of Maf1. Finally, our data reveal a broader effect of Bud27 on PP4 activity by influencing, at least, the phosphorylation of Rad53.
Bud27 是一种 Prefoldin 样蛋白，参与酿酒酵母中三种 RNA 聚合酶介导的转录调控。缺乏 Bud27 会显著影响 RNA pol III 的转录，尽管其涉及的机制尚未确定。在这里，我们表明 Bud27 调节 RNA pol III 转录阻遏物 Maf1 的磷酸化状态，影响其核定位，并可能影响其活性。我们证明 Bud27 与 Maf1 的主要磷酸酶 PP4 在体内相关，这种相互作用对于 Maf1 的适当去磷酸化是必需的。缺乏 Bud27 会降低 PP4 和 Maf1 之间的相互作用、Maf1 的去磷酸化及其核进入。我们的数据揭示了 Bud27 的一个新的核功能，鉴定了 PP4 作为 Bud27 的一个新的相互作用蛋白，并证明了这种 Prefoldin 样蛋白对 Maf1 的翻译后调节的影响。最后，我们的数据通过影响 Rad53 的磷酸化，揭示了 Bud27 对 PP4 活性的更广泛影响。
