Department of Biology, University of Copenhagen, Ole Maaløes Vej 5, DK-2200 Copenhagen N, Denmark.
Institute of Biochemistry, Department of Biology, ETH Zürich, Zürich, Switzerland.
Trends Biochem Sci. 2016 May;41(5):446-459. doi: 10.1016/j.tibs.2016.02.004. Epub 2016 Mar 1.
DSS1/Sem1 is a versatile intrinsically disordered protein. Besides being a bona fide subunit of the 26S proteasome, DSS1 associates with other protein complexes, including BRCA2-RPA, involved in homologous recombination; the Csn12-Thp3 complex, involved in RNA splicing; the integrator, involved in transcription; and the TREX-2 complex, involved in nuclear export of mRNA and transcription elongation. As a subunit of the proteasome, DSS1 functions both in complex assembly and possibly as a ubiquitin receptor. Here, we summarise structural and functional aspects of DSS1/Sem1 with particular emphasis on its multifunctional and disordered properties. We suggest that DSS1/Sem1 can act as a polyanionic adhesive to prevent nonproductive interactions during construction of protein assemblies, uniquely employing different structures when associating with the diverse multisubunit complexes.
DSS1/Sem1 是一种多功能的固有无序蛋白。除了作为 26S 蛋白酶体的真正亚基之外，DSS1 还与其他蛋白质复合物相关联，包括参与同源重组的 BRCA2-RPA；参与 RNA 剪接的 Csn12-Thp3 复合物；参与转录的整合酶；以及参与 mRNA 核输出和转录延伸的 TREX-2 复合物。作为蛋白酶体的一个亚基，DSS1 在复合物组装中发挥作用，并且可能作为泛素受体发挥作用。在这里，我们总结了 DSS1/Sem1 的结构和功能方面，特别强调了其多功能性和无序性。我们认为，DSS1/Sem1 可以作为一种多阴离子黏附物，防止在蛋白质组装过程中发生非生产性相互作用，在与不同的多亚基复合物结合时，独特地采用不同的结构。
