RET1/YOR207C Summary Help

Standard Name RET1 1, 2
Systematic Name YOR207C
Alias PDS2 3 , RPC2 4 , RPC128 5
Feature Type ORF, Verified
Description Second-largest subunit of RNA polymerase III; RNA polymerase III is responsible for the transcription of tRNA and 5S RNA genes, and other low molecular weight RNAs (2, 6 and see Summary Paragraph)
Also known as: C128 6
Name Description Reduced Efficiency of Termination 1
Chromosomal Location
ChrXV:733457 to 730008 | ORF Map | GBrowse
Note: this feature is encoded on the Crick strand.
Genetic position: 117 cM
Gene Ontology Annotations All RET1 GO evidence and references
  View Computational GO annotations for RET1
Molecular Function
Manually curated
Biological Process
Manually curated
Cellular Component
Manually curated
Regulators 2 genes
Classical genetics
reduction of function
Large-scale survey
reduction of function
166 total interaction(s) for 70 unique genes/features.
Physical Interactions
  • Affinity Capture-MS: 129
  • Affinity Capture-RNA: 3
  • Affinity Capture-Western: 4
  • Biochemical Activity: 4
  • Two-hybrid: 2

Genetic Interactions
  • Dosage Growth Defect: 1
  • Dosage Rescue: 1
  • Negative Genetic: 12
  • Positive Genetic: 4
  • Synthetic Growth Defect: 2
  • Synthetic Lethality: 2
  • Synthetic Rescue: 2

Expression Summary
Length (a.a.) 1,149
Molecular Weight (Da) 129,455
Isoelectric Point (pI) 8.17
Phosphorylation PhosphoGRID | PhosphoPep Database
sequence information
ChrXV:733457 to 730008 | ORF Map | GBrowse
Note: this feature is encoded on the Crick strand.
Genetic position: 117 cM
Last Update Coordinates: 2011-02-03 | Sequence: 1996-07-31
Subfeature details
Most Recent Updates
Coordinates Sequence
CDS 1..3450 733457..730008 2011-02-03 1996-07-31
Retrieve sequences
Analyze Sequence
S288C only
S288C vs. other species
S288C vs. other strains
External Links All Associated Seq | E.C. | Entrez Gene | Entrez RefSeq Protein | MIPS | Search all NCBI (Entrez) | UniProtKB
Primary SGDIDS000005733

Nuclear transcription in S. cerevisiae is performed by three multisubunit nuclear RNA polymerases (RNAPs) that are conserved in all eukaryotes (7, 8 and references therein). The roles of these three RNA polymerases are generally conserved across eukaryotes, particularly with respect to production of rRNAs, mRNAs, and tRNAs, though production of other small RNAs is somewhat variable between RNAP II and RNAP III in different species (9). In S. cerevisiae, RNA polymerase I transcribes rDNA to produce the 35S primary rRNA transcript that is processed to produce three of the four mature ribosomal rRNAs: 25S, 18S, and 5.8S. RNA polymerase II produces all nuclear mRNAs, all of the snoRNAs except snR52 (10), four of the five snRNAs (U1, U2, U4, and U5; 11), the RNase MRP RNA encoded by NME1 (9), and the telomerase RNA encoded by TLC1 (12). RNA polymerase III produces the 5S rRNA, all nuclear tRNAs, the U6 snRNA (13), the snR52 snoRNA (10), the RNase P RNA encoded by RPR1 (9), and the 7SL RNA component of the signal recognition particle encoded by SCR1 (9).

Coordinate regulation of these three RNA polymerases is essential, since in rapidly growing yeast cells, much of the transcriptional output of the cell is devoted to the production of ribosomes. About 60% of total cellular transcription is devoted to transcription by RNAP I of the rRNA genes, which comprise about 10% of the entire genome. While mRNAs generally only comprise 5% of total cellular RNA and the 137 ribosomal protein (RP) genes represent only 2% of the genome, it is estimated that 50% of RNAP II transcription occurs on RP genes. RNAP II is also responsible for production of the majority of the snoRNAs, which are collectively involved in maturation of the ribosome. RNAP III plays a similarly important role in production of ribosomes and the process of translation, producing both the 5S rRNA and all nuclear tRNAs, which constitute about 15% of total cellular RNA (reviewed in 14). The TOR pathway is a major factor in this coordinate regulation as it regulates the activity of all three nuclear RNAPs in response to nutrient availability and growth conditions (reviewed in 15, 16, 17, and 18).

In addition to producing the majority of cellular RNA, RNAP I and RNAP III may also play roles in nuclear architecture and genome organization. RNAP I activity may be involved in organizing the rDNA repeats into the nucleolus (reviewed in 19). Active tRNA genes transcribed by RNAP III appear to act as chromatin boundary elements that affect both transcription and DNA replication. Additionally, recombination between dispersed tRNA genes may be a source of genetic instability and evolutionary change (reviewed in 20).

Five genes (RPB5, RPO26, RPB8, RPB10, and RPC10) encode subunits common to all three of the nuclear RNA polymerases. Two genes (RPC40 and RPC19) encode subunits present in both RNAP I and RNAP III; RPB3 and RPB11 encode the corresponding RNAP II subunits. Five more subunits are encoded by a separate gene for each polymerase, but are considered functional equivalents of each other. Thus there are twelve subunits that are conserved in all three of the nuclear RNA polymerases, eleven of which correspond to subunits of Archaeal RNAPs, and five of which also correspond to the subunits of E. coli RNAP. In each, ten of these comprise the enzyme cores, while Rpb4/7 (RNAP II), Rpa14/43 (RNAP I), and Rpc17/25 (RNAP III) form heterodimers which associate with this core and have roles in initiation (21). RNAPs I and III also have two subunits which are homologous to the subunits of the TFIIF general initiation factor for RNAP II, and RNAP III has three additional unique subunits (reviewed in 22, 8, and 23). For tables showing the correspondence between the subunits of the three nuclear RNA polymerases in S. cerevisiae see Cramer et al. 2008 (23) and Werner et al. 2009 (22); to see the correspondence with those of Archaea and bacteria see Cramer 2002 (8).

About RNA polymerase III

In S. cerevisiae, the RNA polymerase III enzyme is composed of seventeen subunits, all of which are essential. RPB5, RPO26, RPB8, RPC10, RPB10, RPC40, and RPC19 encode subunits shared with one or both of the other two nuclear RNA polymerases. RPC53 and RPC37 encode subunits with counterparts in RNAP I, and RPO31, RET1, RPC25, RPC17, and RPC11 encode subunits with counterparts in both RNA polymerases I and II. RPC82, RPC34, and RPC31 encode subunits unique to RNAP III and homologous to a detachable subassembly of human RNAP III implicated in response to specific transcription factors (reviewed in 24, 25, 23, and 22).

In contrast to RNAP I and II promoters, most RNAP III promoters are internal to the expressed sequence of the RNA being transcribed, though there are some exceptions such as the well studied U6 snRNA (encoded by snR6). These internal promoters can be divided into classes based on their organization. Class 1 genes are represented by the 5S rRNA genes, present within the intragenic spacer of the 37S rDNA, and are the only genes which require the specific DNA-binding initiation factor TFIIIA (encoded by PZF1), the archetype zinc finger protein, which then recruits TFIIIC. Class 2 genes comprise the tRNA genes, and others with similar promoter structures, containing internal box A and box B sequence elements which are recognized directly by the six subunit DNA-binding initiation factor TFIIIC (encoded by TFC1, TFC3, TFC4, TFC6, TFC7, and TFC8). In both classes, TFIIIC recruits TFIIIB, which does not bind to DNA by itself despite the fact that it contains the TATA-binding protein TBP (encoded by SPT15), as well as two other subunits (BDP1 and BRF1). Once bound to DNA, TFIIIB brings RNAP III to the promoter and helps initiate transcription (reviewed in 24, 26, and 22). RNAP III transcription is regulated by at least two nutrient-sensing signal transduction pathways, RAS and TOR. Both of these work through Maf1p, which is evolutionarily conserved from yeast to humans, and which represses RNAP III activity when yeast cells experience stress or unfavorable growth conditions (reviewed in 27).

Last updated: 2010-04-29 Contact SGD

References cited on this page View Complete Literature Guide for RET1
1) James P and Hall BD  (1990) ret1-1, a yeast mutant affecting transcription termination by RNA polymerase III. Genetics 125(2):293-303
2) James P, et al.  (1991) The RET1 gene of yeast encodes the second-largest subunit of RNA polymerase III. Structural analysis of the wild-type and ret1-1 mutant alleles. J Biol Chem 266(9):5616-24
3) Briggs MW and Butler JS  (1996) RNA polymerase III defects suppress a conditional-lethal poly(A) polymerase mutation in Saccharomyces cerevisiae. Genetics 143(3):1149-61
4) Nonet M, et al.  (1987) Eucaryotic RNA polymerase conditional mutant that rapidly ceases mRNA synthesis. Mol Cell Biol 7(5):1602-11
5) Riva M, et al.  (1986) Isolation of structural genes for yeast RNA polymerases by immunological screening. Proc Natl Acad Sci U S A 83(6):1554-8
6) Huet J, et al.  (1985) Yeast RNA polymerase C and its subunits. Specific antibodies as structural and functional probes. J Biol Chem 260(28):15304-10
7) Sentenac A  (1985) Eukaryotic RNA polymerases. CRC Crit Rev Biochem 18(1):31-90
8) Cramer P  (2002) Multisubunit RNA polymerases. Curr Opin Struct Biol 12(1):89-97
9) Dieci G, et al.  (2007) The expanding RNA polymerase III transcriptome. Trends Genet 23(12):614-22
10) Moqtaderi Z and Struhl K  (2004) Genome-wide occupancy profile of the RNA polymerase III machinery in Saccharomyces cerevisiae reveals loci with incomplete transcription complexes. Mol Cell Biol 24(10):4118-27
11) Xue D, et al.  (2000) U snRNP assembly in yeast involves the La protein. EMBO J 19(7):1650-60
12) Chapon C, et al.  (1997) Polyadenylation of telomerase RNA in budding yeast. RNA 3(11):1337-51
13) Eschenlauer JB, et al.  (1993) Architecture of a yeast U6 RNA gene promoter. Mol Cell Biol 13(5):3015-26
14) Warner JR  (1999) The economics of ribosome biosynthesis in yeast. Trends Biochem Sci 24(11):437-40
15) Grummt I  (2003) Life on a planet of its own: regulation of RNA polymerase I transcription in the nucleolus. Genes Dev 17(14):1691-702
16) Willis IM, et al.  (2004) Signaling repression of transcription by RNA polymerase III in yeast. Prog Nucleic Acid Res Mol Biol 77:323-53
17) Mayer C and Grummt I  (2006) Ribosome biogenesis and cell growth: mTOR coordinates transcription by all three classes of nuclear RNA polymerases. Oncogene 25(48):6384-91
18) Xiao L and Grove A  (2009) Coordination of Ribosomal Protein and Ribosomal RNA Gene Expression in Response to TOR Signaling. Curr Genomics 10(3):198-205
19) Shaw P and Doonan J  (2005) The nucleolus. Playing by different rules? Cell Cycle 4(1):102-5
20) McFarlane RJ and Whitehall SK  (2009) tRNA genes in eukaryotic genome organization and reorganization. Cell Cycle 8(19):3102-6
21) Kuhn CD, et al.  (2007) Functional architecture of RNA polymerase I. Cell 131(7):1260-72
22) Werner M, et al.  (2009) Structure-function analysis of RNA polymerases I and III. Curr Opin Struct Biol 19(6):740-5
23) Cramer P, et al.  (2008) Structure of eukaryotic RNA polymerases. Annu Rev Biophys 37():337-52
24) Chedin S, et al.  (1998) The yeast RNA polymerase III transcription machinery: a paradigm for eukaryotic gene activation. Cold Spring Harb Symp Quant Biol 63:381-9
25) Geiduschek EP and Kassavetis GA  (2001) The RNA polymerase III transcription apparatus. J Mol Biol 310(1):1-26
26) Huang Y and Maraia RJ  (2001) Comparison of the RNA polymerase III transcription machinery in Schizosaccharomyces pombe, Saccharomyces cerevisiae and human. Nucleic Acids Res 29(13):2675-90
27) Ciesla M and Boguta M  (2008) Regulation of RNA polymerase III transcription by Maf1 protein. Acta Biochim Pol 55(2):215-25