Gene Symbol: SEM1
Description: proteasome regulatory particle lid subunit SEM1
Alias: DSS1, HOD1, proteasome regulatory particle lid subunit SEM1
Species: Saccharomyces cerevisiae S288c
Products:     SEM1

Top Publications

  1. Reinman M, Jantti J, Alfthan K, Keränen S, Söderlund H, Takkinen K. Functional inactivation of the conserved Sem1p in yeast by intrabodies. Yeast. 2003;20:1071-84 pubmed
    ..applied to characterize the function and intracellular localization of a highly conserved Saccharomyces cerevisiae Sem1 protein...
  2. Funakoshi M, Li X, Velichutina I, Hochstrasser M, Kobayashi H. Sem1, the yeast ortholog of a human BRCA2-binding protein, is a component of the proteasome regulatory particle that enhances proteasome stability. J Cell Sci. 2004;117:6447-54 pubmed
    ..Dsk2, is lethal in Saccharomyces cerevisiae and we show here that this lethality can be suppressed by mutations in SEM1, a gene previously recognized as an ortholog of the human gene encoding DSS1, which binds the BRCA2 DNA repair ..
  3. Tomko R, Hochstrasser M. The intrinsically disordered Sem1 protein functions as a molecular tether during proteasome lid biogenesis. Mol Cell. 2014;53:433-43 pubmed publisher
    The intrinsically disordered yeast protein Sem1 (DSS1 in mammals) participates in multiple protein complexes, including the proteasome, but its role(s) within these complexes is uncertain...
  4. Ellisdon A, Dimitrova L, Hurt E, Stewart M. Structural basis for the assembly and nucleic acid binding of the TREX-2 transcription-export complex. Nat Struct Mol Biol. 2012;19:328-36 pubmed publisher
    ..We report the crystal structure of the Sac3-Thp1-Sem1 segment of Saccharomyces cerevisiae TREX-2 that interfaces with the gene expression machinery...
  5. Jantti J, Lahdenranta J, Olkkonen V, Soderlund H, Keranen S. SEM1, a homologue of the split hand/split foot malformation candidate gene Dss1, regulates exocytosis and pseudohyphal differentiation in yeast. Proc Natl Acad Sci U S A. 1999;96:909-14 pubmed
    ..SEM1 is highly conserved among eukaryotic species. Its human homologue, DSS1, has been suggested as a candidate gene for the split hand/split foot malformation disorder...
  6. Tomko R, Hochstrasser M. Incorporation of the Rpn12 subunit couples completion of proteasome regulatory particle lid assembly to lid-base joining. Mol Cell. 2011;44:907-17 pubmed publisher
    ..Rpn12 incorporation thus links proper lid assembly to subsequent assembly steps. ..
  7. Faza M, Kemmler S, Jimeno S, González Aguilera C, Aguilera A, Hurt E, et al. Sem1 is a functional component of the nuclear pore complex-associated messenger RNA export machinery. J Cell Biol. 2009;184:833-46 pubmed publisher
    The evolutionarily conserved protein Sem1/Dss1 is a subunit of the regulatory particle (RP) of the proteasome, and, in mammalian cells, binds the tumor suppressor protein BRCA2. Here, we describe a new function for yeast Sem1...
  8. Qin S, Wang Q, Ray A, Wani G, Zhao Q, Bhaumik S, et al. Sem1p and Ubp6p orchestrate telomeric silencing by modulating histone H2B ubiquitination and H3 acetylation. Nucleic Acids Res. 2009;37:1843-53 pubmed publisher
    ..Simultaneous deletion of SEM1 and UBP6 induces dramatic silencing defect accompanied by significantly increased level of ubiquitinated-histone ..
  9. Marston N, Richards W, Hughes D, Bertwistle D, Marshall C, Ashworth A. Interaction between the product of the breast cancer susceptibility gene BRCA2 and DSS1, a protein functionally conserved from yeast to mammals. Mol Cell Biol. 1999;19:4633-42 pubmed
    ..Using the yeast two-hybrid system with fragments of human BRCA2, we identified an interaction with the human DSS1 (deleted in split hand/split foot) gene...

More Information


  1. Sone T, Saeki Y, Toh e A, Yokosawa H. Sem1p is a novel subunit of the 26 S proteasome from Saccharomyces cerevisiae. J Biol Chem. 2004;279:28807-16 pubmed
    ..the tagged strains of Saccharomyces cerevisiae, and we found that the lid contains a small molecular mass protein, Sem1. The Sem1 protein binds with the 26 S proteasome isolated from a mutant with deletion of SEM1 but not with the 26 S ..
  2. Bohn S, Sakata E, Beck F, Pathare G, Schnitger J, Nagy I, et al. Localization of the regulatory particle subunit Sem1 in the 26S proteasome. Biochem Biophys Res Commun. 2013;435:250-4 pubmed publisher
    ..5 MDa complex has been established recently, with the notable exception of the small acidic subunit Sem1. Here, we localize the C-terminal helix of Sem1 binding to the PCI domain of the subunit Rpn7 using cryo-electron ..
  3. Toikkanen J, Sundqvist L, Keränen S. Kluyveromyces lactis SSO1 and SEB1 genes are functional in Saccharomyces cerevisiae and enhance production of secreted proteins when overexpressed. Yeast. 2004;21:1045-55 pubmed
    ..cerevisiae Seb1p, Sso2p and Sec4p can detect homologous proteins in cell lysates of K. lactis and Pichia pastoris, the latter also in Candida utilis. The GenBank Accession Nos are AF307983 (K. lactis SSO1) and AF318314 (K. lactis SEB1). ..
  4. Pike B, Heierhorst J. Mdt1 facilitates efficient repair of blocked DNA double-strand breaks and recombinational maintenance of telomeres. Mol Cell Biol. 2007;27:6532-45 pubmed
  5. Laporte D, Salin B, Daignan Fornier B, Sagot I. Reversible cytoplasmic localization of the proteasome in quiescent yeast cells. J Cell Biol. 2008;181:737-45 pubmed publisher
    ..Finally, we observe conserved formation and mobilization of these PSGs in the evolutionary distant yeast Schizosaccharomyces pombe. This conservation implies a broad significance for these proteasome reserves. ..
  6. Le Tallec B, Barrault M, Guerois R, Carré T, Peyroche A. Hsm3/S5b participates in the assembly pathway of the 19S regulatory particle of the proteasome. Mol Cell. 2009;33:389-99 pubmed publisher
    ..Finally, we identify the putative species-specific 19S subunit S5b as a functional homolog of the Hsm3 chaperone in mammals. These findings shed light on chaperone-assisted proteasome assembly in eukaryotes. ..
  7. Saeki Y, Isono E, Toh e A. Preparation of ubiquitinated substrates by the PY motif-insertion method for monitoring 26S proteasome activity. Methods Enzymol. 2005;399:215-27 pubmed
    ..In this communication, we describe that Sic1 was successfully ubiquitinated by the PY motif-insertion method and demonstrate that Sic1 thus ubiquitinated was degraded by the purified yeast 26S proteasome. ..
  8. Laribee R, Shibata Y, Mersman D, Collins S, Kemmeren P, Roguev A, et al. CCR4/NOT complex associates with the proteasome and regulates histone methylation. Proc Natl Acad Sci U S A. 2007;104:5836-41 pubmed
    ..These studies implicate CCR4/NOT in the regulation of H3K4me3 through a ubiquitin-dependent pathway that likely involves the proteasome. ..
  9. Shirozu R, Yashiroda H, Murata S. Proteasome Impairment Induces Recovery of Mitochondrial Membrane Potential and an Alternative Pathway of Mitochondrial Fusion. Mol Cell Biol. 2016;36:347-62 pubmed publisher
    ..Our findings demonstrate a new pathway for mitochondrial quality control that is induced by proteasome impairment. ..
  10. García Oliver E, Pascual García P, García Molinero V, Lenstra T, Holstege F, Rodriguez Navarro S. A novel role for Sem1 and TREX-2 in transcription involves their impact on recruitment and H2B deubiquitylation activity of SAGA. Nucleic Acids Res. 2013;41:5655-68 pubmed publisher
    ..We demonstrate that TREX-2 subunit Sem1 also participates in transcription activation...
  11. Taverner T, Hernandez H, Sharon M, Ruotolo B, Matak Vinkovic D, Devos D, et al. Subunit architecture of intact protein complexes from mass spectrometry and homology modeling. Acc Chem Res. 2008;41:617-27 pubmed publisher
    ..Overall therefore this mass spectrometry and homology modeling approach has given significant insight into the structure of two previously intractable protein complexes and as such has broad application in structural biology. ..
  12. Funakoshi M, Tomko R, Kobayashi H, Hochstrasser M. Multiple assembly chaperones govern biogenesis of the proteasome regulatory particle base. Cell. 2009;137:887-99 pubmed publisher
    ..Our results demonstrate that proteasomal RP biogenesis requires multiple, functionally overlapping chaperones and suggest a model in which subunits form specific subcomplexes that then assemble into the base. ..
  13. Tomko R, Taylor D, Chen Z, Wang H, Rappsilber J, Hochstrasser M. A Single α Helix Drives Extensive Remodeling of the Proteasome Lid and Completion of Regulatory Particle Assembly. Cell. 2015;163:432-44 pubmed publisher
    ..Such assembly-coupled conformational switching is reminiscent of viral particle maturation and may represent a commonly used mechanism to enforce hierarchical assembly in multisubunit complexes. ..
  14. Laribee R, Krogan N, Xiao T, Shibata Y, Hughes T, Greenblatt J, et al. BUR kinase selectively regulates H3 K4 trimethylation and H2B ubiquitylation through recruitment of the PAF elongation complex. Curr Biol. 2005;15:1487-93 pubmed
    ..Our data reveal a novel function for the BUR kinase in transcriptional regulation through the selective control of histone modifications. ..
  15. Dziembowski A, Malewicz M, Minczuk M, Golik P, Dmochowska A, Stepien P. The yeast nuclear gene DSS1, which codes for a putative RNase II, is necessary for the function of the mitochondrial degradosome in processing and turnover of RNA. Mol Gen Genet. 1998;260:108-14 pubmed
    The yeast nuclear gene DSS1 codes for a mitochondrial protein containing regions of homology to bacterial RNase II and can act as a multicopy suppressor of a deletion of the SUV3 gene, which encodes an RNA helicase...
  16. Libuda D, Winston F. Alterations in DNA replication and histone levels promote histone gene amplification in Saccharomyces cerevisiae. Genetics. 2010;184:985-97 pubmed publisher
    ..Taken together, our results suggest that either reduced histone levels or slowed replication forks stimulate the HTA2-HTB2 amplification event, contributing to the restoration of normal chromatin structure. ..
  17. Saeki Y, Toh e A, Kudo T, Kawamura H, Tanaka K. Multiple proteasome-interacting proteins assist the assembly of the yeast 19S regulatory particle. Cell. 2009;137:900-13 pubmed publisher
    ..Our results indicate that the RP assembly is a highly organized and elaborate process orchestrated by multiple proteasome-dedicated chaperones. ..
  18. Concannon C, Lahue R. Nucleotide excision repair and the 26S proteasome function together to promote trinucleotide repeat expansions. DNA Repair (Amst). 2014;13:42-9 pubmed publisher
    ..This work provides the first evidence that both subpathways of NER can promote threshold-length TNR expansions and that NER interacts with the proteasome to drive expansions. ..
  19. Dambacher C, Worden E, Herzik M, Martin A, Lander G. Atomic structure of the 26S proteasome lid reveals the mechanism of deubiquitinase inhibition. elife. 2016;5:e13027 pubmed publisher
  20. Aibara S, Bai X, Stewart M. The Sac3 TPR-like region in the Saccharomyces cerevisiae TREX-2 complex is more extensive but independent of the CID region. J Struct Biol. 2016;195:316-324 pubmed publisher
    ..The TREX-2 complex is based on a Sac3 scaffold to which Thp1, Sem1, Cdc31, and Sus1 bind...
  21. Concannon C, Lahue R. The 26S proteasome drives trinucleotide repeat expansions. Nucleic Acids Res. 2013;41:6098-108 pubmed publisher
    ..This study reports that the multi-functional protein Sem1 is a novel driver of TNR expansions in budding yeast. Mutants of SEM1 suppress up to 90% of expansions...
  22. Cortajarena A, Liu T, Hochstrasser M, Regan L. Designed proteins to modulate cellular networks. ACS Chem Biol. 2010;5:545-52 pubmed publisher
    ..Using this approach, we identified modules that bind tightly and specifically to Dss1, a small human protein that interacts with the tumor suppressor protein BRCA2...