The world's first wiki where authorship really matters (Nature Genetics, 2008). Due credit and reputation for authors. Imagine a global collaborative knowledge base for original thoughts. Search thousands of articles and collaborate with scientists around the globe.

wikigene or wiki gene protein drug chemical gene disease author authorship tracking collaborative publishing evolutionary knowledge reputation system wiki2.0 global collaboration genes proteins drugs chemicals diseases compound
Hoffmann, R. A wiki for the life sciences where authorship matters. Nature Genetics (2008)



Gene Review

RPO21  -  DNA-directed RNA polymerase II core...

Saccharomyces cerevisiae S288c

Synonyms: D2150, DNA-directed RNA polymerase II subunit RPB1, DNA-directed RNA polymerase III largest subunit, RNA polymerase II subunit 1, RNA polymerase II subunit B1, ...
Welcome! If you are familiar with the subject of this article, you can contribute to this open access knowledge base by deleting incorrect information, restructuring or completely rewriting any text. Read more.

Disease relevance of RPO21


High impact information on RPO21

  • All strains containing suppressor mutations in RPB1 and RPB2 have reduced transcription of the INO1 gene and an inositol requirement [3].
  • We have determined the nucleotide sequence of two yeast RNA polymerase genes, RPO21 and RPO31, which encode the largest subunits of RNA polymerases II and III, respectively [4].
  • Export ceases in either the presence of the RNA synthesis inhibitor thiolutin or in a temperature-sensitive RNA polymerase (rpb1) mutant [5].
  • RPB9 appears to play a unique role in transcription initiation, as the defects revealed in its absence are distinct from those seen with mutants in RNA polymerase subunit RPB1 and factor e (TFIIB), two other yeast proteins also involved in start site selection [6].
  • The diverse functions of Saccharomyces cerevisiae RNA polymerase II are partitioned among its 12 subunits, designated RPB1-RPB12 [6].

Chemical compound and disease context of RPO21


Biological context of RPO21

  • We have used a yeast genomic library to isolate plasmids that can suppress a temperature-sensitive mutation in RPO21 (rpo21-4), with the goal of identifying gene products that interact with the largest subunit of RNAPII [7].
  • However, scs32 was unable to suppress the ts phenotype of mutant alleles of RPO21, or result in accumulation of the unstable rpo21-4p [8].
  • Synthetic lethality was associated with double sua7 sua8 suppressor mutations, and recessive sua7 mutants failed to fully complement recessive sua8 mutants in heterozygous diploids (nonallelic noncomplementation) [9].
  • The sua8 suppressors of Saccharomyces cerevisiae encode replacements of conserved residues within the largest subunit of RNA polymerase II and affect transcription start site selection similarly to sua7 (TFIIB) mutations [9].
  • Shorter or longer RPO21 C-terminal domains enhanced or partially suppressed, respectively, the effects of deletions in the transcriptional-activation domains of GAL4 [10].

Anatomical context of RPO21

  • The data show that B220 inhibits neutrophil release of reactive oxygen species, as well as intracellular generation of reactive oxygen species [11].
  • In addition we show here that the levels of expression of this same RNA polymerase II subunit directly affect cellular differentiation, reducing the rate of cell proliferation, clonogenicity and increasing the expression of E-cadherin, a marker of epithelial cell differentiation [12].

Associations of RPO21 with chemical compounds

  • A screen for mutations in RPO21 that confer 6AU sensitivity identified seven mutations that had been generated by either linker-insertion or random chemical mutagenesis [13].
  • Underproduction of RNAPII was achieved by expressing the gene (RPO21), encoding the largest subunit of the enzyme, from the LEU2 promoter or a weaker derivative of it, two promoters that can be repressed by the addition of leucine to the growth medium [14].
  • We show here that Rpb1 ubiquitination and degradation are induced in vivo by UV irradiation and by the UV-mimetic compound 4-nitroquinoline-1-oxide (4-NQO) and that a functional RSP5 gene product is required for this effect [15].
  • Two of the three WW domains are required for the essential in vivo function, while the C2 domain is not, and requirements for Rpb1 binding and ubiquitination lie within the region required for in vivo function [16].
  • Treatment of yeast and human cells with DNA-damaging agents elicits lysine 48-linked polyubiquitylation of Rpb1, the largest subunit of RNA polymerase II (Pol II), which targets Pol II for proteasomal degradation [17].

Physical interactions of RPO21

  • These data indicate that RPB2 and RPB3 form a complex that subsequently interacts with RPB1 during the assembly of RNA polymerase II [18].
  • Rpb5 was found to interact with any fragment of Rpb1 that contained the region H, which is conserved among the subunit 1 homologues of all RNA polymerases, including the beta' subunit of prokaryotic RNA polymerases [19].

Enzymatic interactions of RPO21

  • Third, the association of SET2 with CTD phosphorylated RPO21 remained in the absence of ssn3 [20].
  • Fusion of the Rpb1 carboxyl-terminal domain to another protein also causes that protein to be ubiquitinated by Rsp5 [21].

Regulatory relationships of RPO21

  • We have changed the number of heptapeptide repeats in this yeast RPO21 C-terminal domain and have expressed these mutant RNA polymerase II polypeptides in yeast cells containing either wild-type or defective GAL4 proteins [10].
  • We found that cells that underproduced RPO21 were unable to derepress fully the expression of a reporter gene under the control of the INO1 UAS [14].
  • We found that the 6AU sensitivity of the rpo21 mutants can be suppressed by increasing the dosage of the wild-type PPR2 gene, presumably as a result of overexpression of TFIIS [13].
  • Purified recombinant Srb4 subcomplex stimulated basal transcription of pol II but had little effect on activated transcription and phosphorylation of the C-terminal domain of the Rpb1 subunit of pol II [22].

Other interactions of RPO21

  • These results support the idea that the RPO26 and RPO21 gene products interact [7].
  • Analysis of cyc1 transcripts from sua8 mutants revealed that suppression is a consequence of diminished transcription initiation at the normal start sites in favor of initiation at downstream sites, including a site between the aberrant and normal ATG start codons [9].
  • A potential DNA-binding site (zinc-binding motif) is conserved in the N-terminal region I. Remarkably, the A190 subunit does not harbor the heptapeptide repeated sequence present in the B220 subunit [1].
  • RNA polymerase II subunit composition, stoichiometry, and phosphorylation were investigated in Saccharomyces cerevisiae by attaching an epitope coding sequence to a well-characterized RNA polymerase II subunit gene (RPB3) and by immunoprecipitating the product of this gene with its associated polypeptides [23].
  • The same RPO21 mutations also affected transcriptional activation by a GAL4-GCN4 chimera [10].

Analytical, diagnostic and therapeutic context of RPO21

  • The utility of HisUb as a method for purification of proteins ubiquitinated in vivo was demonstrated by metal chelation chromatography of yeast extracts expressing HisUb and immunoblotting for Rpb1, the largest subunit of RNA polymerase II [24].


  1. RPA190, the gene coding for the largest subunit of yeast RNA polymerase A. Mémet, S., Gouy, M., Marck, C., Sentenac, A., Buhler, J.M. J. Biol. Chem. (1988) [Pubmed]
  2. Mutations in the Saccharomyces cerevisiae RPB1 Gene Conferring Hypersensitivity to 6-Azauracil. Malagon, F., Kireeva, M.L., Shafer, B.K., Lubkowska, L., Kashlev, M., Strathern, J.N. Genetics (2006) [Pubmed]
  3. A suppressor of a HIS4 transcriptional defect encodes a protein with homology to the catalytic subunit of protein phosphatases. Arndt, K.T., Styles, C.A., Fink, G.R. Cell (1989) [Pubmed]
  4. Extensive homology among the largest subunits of eukaryotic and prokaryotic RNA polymerases. Allison, L.A., Moyle, M., Shales, M., Ingles, C.J. Cell (1985) [Pubmed]
  5. A protein that shuttles between the nucleus and the cytoplasm is an important mediator of RNA export. Lee, M.S., Henry, M., Silver, P.A. Genes Dev. (1996) [Pubmed]
  6. RNA polymerase II subunit RPB9 is required for accurate start site selection. Hull, M.W., McKune, K., Woychik, N.A. Genes Dev. (1995) [Pubmed]
  7. A suppressor of an RNA polymerase II mutation of Saccharomyces cerevisiae encodes a subunit common to RNA polymerases I, II, and III. Archambault, J., Schappert, K.T., Friesen, J.D. Mol. Cell. Biol. (1990) [Pubmed]
  8. Genetic evidence for selective degradation of RNA polymerase subunits by the 20S proteasome in Saccharomyces cerevisiae. Nouraini, S., Xu, D., Nelson, S., Lee, M., Friesen, J.D. Nucleic Acids Res. (1997) [Pubmed]
  9. The sua8 suppressors of Saccharomyces cerevisiae encode replacements of conserved residues within the largest subunit of RNA polymerase II and affect transcription start site selection similarly to sua7 (TFIIB) mutations. Berroteran, R.W., Ware, D.E., Hampsey, M. Mol. Cell. Biol. (1994) [Pubmed]
  10. Mutations in RNA polymerase II enhance or suppress mutations in GAL4. Allison, L.A., Ingles, C.J. Proc. Natl. Acad. Sci. U.S.A. (1989) [Pubmed]
  11. The synthetic non-toxic drug 2,3-dimethyl-6(2-dimethylaminoethyl)-6H-indolo-(2,3-b)quinoxaline inhibits neutrophil production of reactive oxygen species. Harbecke, O., Dahlgren, C., Bergman, J., Möller, L. J. Leukoc. Biol. (1999) [Pubmed]
  12. Levels of expression of hRPB11, a core subassembly subunit of human RNA polymerase II, affect doxorubicin sensitivity and cellular differentiation. Bruno, T., Leonetti, C., Aloe, S., Iacobini, C., Floridi, A., Di Tondo, U., Punturieri, A., Fanciulli, M. FEBS Lett. (1998) [Pubmed]
  13. Genetic interaction between transcription elongation factor TFIIS and RNA polymerase II. Archambault, J., Lacroute, F., Ruet, A., Friesen, J.D. Mol. Cell. Biol. (1992) [Pubmed]
  14. Underproduction of the largest subunit of RNA polymerase II causes temperature sensitivity, slow growth, and inositol auxotrophy in Saccharomyces cerevisiae. Archambault, J., Jansma, D.B., Friesen, J.D. Genetics (1996) [Pubmed]
  15. Rsp5 ubiquitin-protein ligase mediates DNA damage-induced degradation of the large subunit of RNA polymerase II in Saccharomyces cerevisiae. Beaudenon, S.L., Huacani, M.R., Wang, G., McDonnell, D.P., Huibregtse, J.M. Mol. Cell. Biol. (1999) [Pubmed]
  16. Functional domains of the Rsp5 ubiquitin-protein ligase. Wang, G., Yang, J., Huibregtse, J.M. Mol. Cell. Biol. (1999) [Pubmed]
  17. ELA1 and CUL3 Are Required Along with ELC1 for RNA Polymerase II Polyubiquitylation and Degradation in DNA-Damaged Yeast Cells. Ribar, B., Prakash, L., Prakash, S. Mol. Cell. Biol. (2007) [Pubmed]
  18. Mutations in the three largest subunits of yeast RNA polymerase II that affect enzyme assembly. Kolodziej, P.A., Young, R.A. Mol. Cell. Biol. (1991) [Pubmed]
  19. Mapping of Rpb3 and Rpb5 contact sites on two large subunits, Rpb1 and Rpb2, of the RNA polymerase II from fission yeast. Miyao, T., Honda, A., Qu, Z., Ishihama, A. Mol. Gen. Genet. (1998) [Pubmed]
  20. The histone 3 lysine 36 methyltransferase, SET2, is involved in transcriptional elongation. Schaft, D., Roguev, A., Kotovic, K.M., Shevchenko, A., Sarov, M., Shevchenko, A., Neugebauer, K.M., Stewart, A.F. Nucleic Acids Res. (2003) [Pubmed]
  21. The large subunit of RNA polymerase II is a substrate of the Rsp5 ubiquitin-protein ligase. Huibregtse, J.M., Yang, J.C., Beaudenon, S.L. Proc. Natl. Acad. Sci. U.S.A. (1997) [Pubmed]
  22. The structural and functional organization of the yeast mediator complex. Kang, J.S., Kim, S.H., Hwang, M.S., Han, S.J., Lee, Y.C., Kim, Y.J. J. Biol. Chem. (2001) [Pubmed]
  23. RNA polymerase II subunit composition, stoichiometry, and phosphorylation. Kolodziej, P.A., Woychik, N., Liao, S.M., Young, R.A. Mol. Cell. Biol. (1990) [Pubmed]
  24. Histidine-tagged ubiquitin substitutes for wild-type ubiquitin in Saccharomyces cerevisiae and facilitates isolation and identification of in vivo substrates of the ubiquitin pathway. Ling, R., Colón, E., Dahmus, M.E., Callis, J. Anal. Biochem. (2000) [Pubmed]
WikiGenes - Universities