Shidlovskii Yulii V, Ulianova Yulia A, Shaposhnikov Alexander V, Kolesnik Valeria V, Pravednikova Anna E, Stepanov Nikita G, Chetverina Darya, Saccone Giuseppe, Lebedeva Lyubov A, Chmykhalo Victor K, Giordano Ennio
Laboratory of Gene Expression Regulation in Development, Institute of Gene Biology, Russian Academy of Sciences, 119334 Moscow, Russia.
Department of Biology and General Genetics, Sechenov University, 119992 Moscow, Russia.
Int J Mol Sci. 2024 Nov 28;25(23):12781. doi: 10.3390/ijms252312781.
SAYP and Bap170, subunits of the SWI/SNF remodeling complex, have the ability to support enhancer-dependent transcription when artificially recruited to the promoter on a transgene. We found that the phenomenon critically depends on two subunits of the Mediator kinase module, Med12 and Med13 but does not require the two other subunits of the module (Cdk8 and CycC) or other subunits of the core part of the complex. A cooperation of the above proteins in active transcription was also observed at endogenous loci, but the contribution of the subunits to the activity of a particular gene differed in different loci. The factors SAYP/Bap170 and Med12/Med13 did not form sufficiently stable interactions in the extract, and their cooperation was apparently local at regulatory elements, the presence of SAYP and Bap170 in a locus being necessary for stable recruitment of Med12 and Med13 to the locus. In addition to the above factors, the Nelf-A protein was found to participate in the process. The cooperation of the factors, independent of enzymatic activities of the complexes they are part of, appears to be a novel mechanism that maintains promoter activity and may be used in many loci of the genome. Extended intrinsically disordered regions of the factors were assumed to sustain the mechanism.
SWI/SNF重塑复合体的亚基SAYP和Bap170在通过转基因人工招募到启动子时，具有支持增强子依赖性转录的能力。我们发现，这一现象关键取决于中介体激酶模块的两个亚基Med12和Med13，但不需要该模块的其他两个亚基（Cdk8和CycC）或复合体核心部分的其他亚基。在基因内源性位点也观察到上述蛋白质在活跃转录过程中的协同作用，但不同位点上这些亚基对特定基因活性的贡献有所不同。在提取物中，SAYP/Bap170和Med12/Med13这些因子并未形成足够稳定的相互作用，它们的协同作用显然是在调控元件处局部发生的，一个位点中SAYP和Bap170的存在对于将Med12和Med13稳定招募到该位点是必要的。除了上述因子外，还发现Nelf-A蛋白参与了这一过程。这些因子之间的协同作用与其所属复合体的酶活性无关，似乎是一种维持启动子活性的新机制，可能在基因组的许多位点发挥作用。这些因子的延伸的内在无序区域被认为维持了这一机制。
