RPS18B/YML026C Summary 
RPS18B BASIC INFORMATION
| Standard Name | RPS18B |
|---|---|
| Systematic Name | YML026C |
| Feature Type | ORF, Verified |
| Description | Protein component of the small (40S) ribosomal subunit; nearly identical to Rps18Ap and has similarity to E. coli S13 and rat S18 ribosomal proteins (1 and see Summary Paragraph) 
|
| Name Description | Ribosomal Protein of the Small subunit |
| Gene Product Alias | S18B 2 |
| GO Annotations | All RPS18B GO evidence and references |
|---|---|
| View Computational GO annotations for RPS18B | |
| Molecular Function | |
| Manually curated | |
| Biological Process | |
| Manually curated | |
| Cellular Component | |
| Manually curated | |
| High-throughput |
| Mutant Phenotype | All RPS18B Phenotype details and references |
|---|---|
| Classical genetics | |
| null |
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| Large-scale survey | |
| null |
|
| Interactions | RPS18B All interactions details and references |
|---|---|
| 11 total interaction(s) for 10 unique genes/features. | |
| Physical Interactions |
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| Genetic Interactions |
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| External Links | All Associated Seq | Entrez Gene | Entrez RefSeq Protein | MIPS | UniProtKB |
|---|
| Primary SGDID | S000004488 |
|---|
RPS18B RESOURCES
| SGD ORF map | GBrowse |
|---|---|
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Click on histogram for expression summary
Expression Summary
ADDITIONAL INFORMATION for RPS18B
SUMMARY PARAGRAPH for RPS18B
About yeast ribosomes...
Ribosomes are highly conserved large ribonucleoprotein (RNP) particles, consisting in yeast of a large 60S subunit and a small 40S subunit, that perform protein synthesis. Yeast ribosomes contain one copy each of four ribosomal RNAs (5S, 5.8S, 18S, and 25S; produced in two separate transcripts encoded within the rDNA repeat present as hundreds of copies on Chromosome 12) and 78 different ribosomal proteins (r-proteins), which are encoded by 137 different genes scattered about the genome, 59 of which are duplicated (3). The 60S subunit contains 42 proteins and three RNA molecules: 25S RNA of 3392 nt, hydrogen bonded to the 5.8S RNA of 158 nt and associated with the 5S RNA of 121 nt. The 40S subunit has a single 18S RNA of 1798 nt and 32 proteins (4). All yeast ribosomal proteins have a mammalian homolog (5).
In a rapidly growing yeast cell, 60% of total transcription is devoted to ribosomal RNA, and 50% of RNA polymerase II transcription and 90% of mRNA splicing are devoted to the production of mRNAs for r-proteins. Coordinate regulation of the rRNA genes and 137 r-protein genes is affected by nutritional cues and a number of signal transduction pathways that can abruptly induce or silence the ribosomal genes, whose transcripts have naturally short lifetimes, leading to major implications for the expression of other genes as well (6, 7, 8). The expression of some r-protein genes is influenced by Abf1p (9), and most are directly induced by binding of Rap1p to their promoters, which excludes nucleosomes and recruits Fhl1p and Ifh1p to drive transcription (10).
Ribosome assembly is a complex process, with different steps occurring in different parts of the cell. Ribosomal protein genes are transcribed in the nucleus, and the mRNA is transported to the cytoplasm for translation. The newly synthesized r-proteins then enter the nucleus and associate in the nucleolus with the two rRNA transcripts, one of which is methylated and pseudouridylated (view sites of modifications), and then cleaved into three individual rRNAs (18S, 5.8S, and 25S) as part of the assembly process (3). Separate ribosomal subunits are then transported from the nucleolus to the cytoplasm where they assemble into mature ribosomes before functioning in translation (11, 12). Blockage of subunit assembly, such as due to inhibition of rRNA synthesis or processing, results in degradation of newly synthesized r-proteins (13, 12). (For more information on the early steps of rRNA processing and small ribosomal subunit assembly, see the summary paragraph for the U3 snoRNA, encoded by snR17A and snR17B.)
Last updated: 2007-02-15
REFERENCES CITED ON THIS PAGE [View Complete Literature Guide for RPS18B]
| 1) | Lecompte O, et al. (2002) Comparative analysis of ribosomal proteins in complete genomes: an example of reductive evolution at the domain scale. Nucleic Acids Res 30(24):5382-90 |
| 2) | Planta RJ and Mager WH (1998) The list of cytoplasmic ribosomal proteins of Saccharomyces cerevisiae. Yeast 14(5):471-7 |
| 3) | Venema J and Tollervey D (1999) Ribosome synthesis in Saccharomyces cerevisiae. Annu Rev Genet 33:261-311 |
| 4) | Verschoor A, et al. (1998) Three-dimensional structure of the yeast ribosome. Nucleic Acids Res 26(2):655-61 |
| 5) | Mager WH, et al. (1997) A new nomenclature for the cytoplasmic ribosomal proteins of Saccharomyces cerevisiae. Nucleic Acids Res 25(24):4872-5 |
| 6) | Li B, et al. (1999) Transcriptional elements involved in the repression of ribosomal protein synthesis. Mol Cell Biol 19(8):5393-404 |
| 7) | Zhao Y, et al. (2003) Autoregulation in the biosynthesis of ribosomes. Mol Cell Biol 23(2):699-707 |
| 8) | Warner JR (1999) The economics of ribosome biosynthesis in yeast. Trends Biochem Sci 24(11):437-40 |
| 9) | Mager WH and Planta RJ (1990) Multifunctional DNA-binding proteins mediate concerted transcription activation of yeast ribosomal protein genes. Biochim Biophys Acta 1050(1-3):351-5 |
| 10) | Zhao Y, et al. (2006) Fine-structure analysis of ribosomal protein gene transcription. Mol Cell Biol 26(13):4853-62 |
| 11) | Moritz M, et al. (1990) Depletion of yeast ribosomal proteins L16 or rp59 disrupts ribosome assembly. J Cell Biol 111(6 Pt 1):2261-74 |
| 12) | Milgrom E, et al. (2007) Loss of vacuolar proton-translocating ATPase activity in yeast results in chronic oxidative stress. J Biol Chem 282(10):7125-36 |
| 13) | Wang S, et al. (2007) Influence of Substrate Conformation on the Deglycosylation of Ribonuclease B by Recombinant Yeast Peptide:N-glycanase. Acta Biochim Biophys Sin (Shanghai) 39(1):8-14 |
