SNM1/YDR478W Summary Help

Standard Name SNM1 1
Systematic Name YDR478W
Feature Type ORF, Verified
Description Ribonuclease MRP complex subunit; ribonuclease (RNase) MRP cleaves pre-rRNA and has a role in cell cycle-regulated degradation of daughter cell-specific mRNAs; binds to the NME1 RNA subunit of RNase MRP (1, 2, 3 and see Summary Paragraph)
Name Description Suppressor of Nuclear Mitochondrial endoribonuclease 1
Chromosomal Location
ChrIV:1414575 to 1415171 | ORF Map | GBrowse
Gbrowse
Gene Ontology Annotations All SNM1 GO evidence and references
  View Computational GO annotations for SNM1
Molecular Function
Manually curated
Biological Process
Manually curated
Cellular Component
Manually curated
Regulators 1 genes
Resources
Classical genetics
conditional
null
Large-scale survey
conditional
null
reduction of function
unspecified
Resources
36 total interaction(s) for 21 unique genes/features.
Physical Interactions
  • Affinity Capture-MS: 6
  • Affinity Capture-RNA: 1
  • Affinity Capture-Western: 4
  • Co-purification: 1
  • PCA: 2
  • Two-hybrid: 8

Genetic Interactions
  • Dosage Rescue: 1
  • Negative Genetic: 3
  • Positive Genetic: 1
  • Synthetic Growth Defect: 4
  • Synthetic Lethality: 2
  • Synthetic Rescue: 3

Resources
Expression Summary
histogram
Resources
Length (a.a.) 198
Molecular Weight (Da) 22,541
Isoelectric Point (pI) 10.42
Localization
Phosphorylation PhosphoGRID | PhosphoPep Database
Structure
Homologs
sequence information
ChrIV:1414575 to 1415171 | ORF Map | GBrowse
SGD ORF map
Last Update Coordinates: 2011-02-03 | Sequence: 1996-07-31
Subfeature details
Relative
Coordinates
Chromosomal
Coordinates
Most Recent Updates
Coordinates Sequence
CDS 1..597 1414575..1415171 2011-02-03 1996-07-31
Retrieve sequences
Analyze Sequence
S288C only
S288C vs. other species
S288C vs. other strains
Resources
External Links All Associated Seq | Entrez Gene | Entrez RefSeq Protein | MIPS | Search all NCBI (Entrez) | UniProtKB
Primary SGDIDS000002886
SUMMARY PARAGRAPH for SNM1

SNM1 encodes an essential subunit of the enzyme RNase MRP, along with the protein subunits Rpp1p, Pop1p, Pop3p, Pop4p, Pop5p, Pop6p, Pop7p, Pop8p, and Rmp1p, and the RNA subunit NME1 (4, 5, 1). Both genetic and direct physical interactions are observed between Snm1p and the NME1 RNA (1). All of the protein subunits of RNase MRP except for Snm1p and Rmp1p are shared with the related enzyme RNase P (see below). RNase MRP (RNase mitochondrial RNA processing) is required for processing of pre-rRNA, and in vitro performs cleavage of pre-5.8S rRNA at the A3 site (6, 7, 8). In S. cerevisiae, RNase MRP has also been shown to be required for progression of the cell cycle at the end of mitosis: mutations in genes encoding several RNase MRP subunits, including SNM1, cause delays in late mitosis and the accumulation of cells in telophase, with large buds and dumbbell-shaped nuclei (9). This cell cycle delay is due to a defect in degradation of the CLB2 mRNA, which must occur in order for mitosis to be completed (10). RNase MRP has a role in degradation of the CLB2 mRNA, and likely also degradation of other specific mRNA substrates, via cleavage of the mRNA 5' untranslated region which allows further degradation of the mRNA by Kem1p (3).

The localization of RNase MRP changes during the cell cycle, reflecting these multiple roles in RNA processing. Most RNase MRP is located in the nucleolus, where it performs pre-rRNA processing (3). However, during mitosis, RNase MRP is localized throughout the nucleus and also localizes, along with the Kem1p nuclease, to a specialized type of mRNA processing body (P body) called the TAM body (temporal asymmetric MRP body) that is present in a single copy in the cytoplasm of daughter cells (3). The TAM body is the site of specific degradation of the CLB2 mRNA and probably other mRNAs as well. Asymmetric localization of the TAM body to daughter cells is dependent on the locasome, which is a protein-mRNA complex that transports at least 30 different mRNAs, for example the ASH1 mRNA, specifically to daughter cells (3). This degradation of cell cycle-regulated, daughter cell-specific mRNAs is required for completion of mitosis (3, 9, 10).

RNase MRP is also thought to have a role in the initiation of mitochondrial DNA replication in mammals, via site-specific cleavage of mitochondrial RNAs to create replication primers, and a portion of RNase P has been detected in mammalian mitochondria (11, 8). Although S. cerevisiae RNase MRP can cleave both yeast and mammalian RNAs in a site-specific manner in vitro (8), it has not been detected in mitochondria, nor has a role in mitochondrial DNA replication been demonstrated.

RNase MRP is highly conserved throughout evolution, although putative orthologs of the Snm1p subunit have not been identified outside of the fungi (reviewed in 12). Mutations of the human homolog of the NME1 RNA subunit, RMRP (OMIM), are associated with the developmental disorder cartilage-hair hypoplasia (CHH) (reviewed in 13).

Note:
Three enzyme complexes involved in RNA processing are evolutionarily and physically related, and are easily confused with each other (see 14 and references therein). Mitochondrial RNase P is composed of the mitochondrially-encoded RPM1 RNA and the nuclear-encoded protein Rpm2p; it removes the 5' leaders from mitochondrial tRNA precursors. Nuclear RNase P, which removes the 5' leaders from cytoplasmic tRNA precursors, is composed of the RPR1 RNA subunit and Pop1p, Pop3p, Pop4p, Pop5p, Pop6p, Pop7p, Pop8p, Rpp1p, and Rpr2p. RNase MRP (RNase mitochondrial RNA processing) shares some subunits with nuclear RNase P: it is composed of an RNA subunit encoded by the nuclear NME1 gene and the protein subunits Rpp1p, Snm1p, Pop1p, Pop3p, Pop4p, Pop5p, Pop6p, Pop7p, Pop8p, and Rmp1p. RNase MRP processes pre-rRNAs in the nucleolus and is also present during mitosis in cytoplasmic RNA processing bodies, where it has a role in degradation of daughter cell-specific mRNAs via cleavage of 5' untranslated regions. In mammals, a portion of RNase MRP enters mitochondria and processes RNAs to create RNA primers for DNA replication, but this has not been shown in fungi.

Last updated: 2007-03-08 Contact SGD

References cited on this page View Complete Literature Guide for SNM1
1) Schmitt ME and Clayton DA  (1994) Characterization of a unique protein component of yeast RNase MRP: an RNA-binding protein with a zinc-cluster domain. Genes Dev 8(21):2617-28
2) Houser-Scott F, et al.  (2002) Interactions among the protein and RNA subunits of Saccharomyces cerevisiae nuclear RNase P. Proc Natl Acad Sci U S A 99(5):2684-9
3) Gill T, et al.  (2006) A specialized processing body that is temporally and asymmetrically regulated during the cell cycle in Saccharomyces cerevisiae. J Cell Biol 173(1):35-45
4) Schmitt ME and Clayton DA  (1992) Yeast site-specific ribonucleoprotein endoribonuclease MRP contains an RNA component homologous to mammalian RNase MRP RNA and essential for cell viability. Genes Dev 6(10):1975-85
5) Chamberlain JR, et al.  (1998) Purification and characterization of the nuclear RNase P holoenzyme complex reveals extensive subunit overlap with RNase MRP. Genes Dev 12(11):1678-90
6) Schmitt ME and Clayton DA  (1993) Nuclear RNase MRP is required for correct processing of pre-5.8S rRNA in Saccharomyces cerevisiae. Mol Cell Biol 13(12):7935-41
7) Chu S, et al.  (1994) The RNA of RNase MRP is required for normal processing of ribosomal RNA. Proc Natl Acad Sci U S A 91(2):659-63
8) Stohl LL and Clayton DA  (1992) Saccharomyces cerevisiae contains an RNase MRP that cleaves at a conserved mitochondrial RNA sequence implicated in replication priming. Mol Cell Biol 12(6):2561-9
9) Cai T, et al.  (2002) The Saccharomyces cerevisiae RNase mitochondrial RNA processing is critical for cell cycle progression at the end of mitosis. Genetics 161(3):1029-42
10) Gill T, et al.  (2004) RNase MRP cleaves the CLB2 mRNA to promote cell cycle progression: novel method of mRNA degradation. Mol Cell Biol 24(3):945-53
11) Li K, et al.  (1994) Subcellular partitioning of MRP RNA assessed by ultrastructural and biochemical analysis. J Cell Biol 124(6):871-82
12) Rosenblad MA, et al.  (2006) Inventory and analysis of the protein subunits of the ribonucleases P and MRP provides further evidence of homology between the yeast and human enzymes. Nucleic Acids Res 34(18):5145-5156
13) Martin AN and Li Y  (2007) RNase MRP RNA and human genetic diseases. Cell Res 17(3):219-26
14) Xiao S, et al.  (2001) Eukaryotic ribonuclease P: increased complexity to cope with the nuclear pre-tRNA pathway. J Cell Physiol 187(1):11-20