Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.1.13.1 (exoribonuclease)
 732 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A mutation in NMD3 was found to be lethal in the absence of XRN1, which encodes the major cytoplasmic exoribonuclease responsible for mRNA turnover. Molecular genetic analysis of NMD3 revealed that it is an essential gene required for stable 60S ribosomal subunits. Cells bearing a temperature-sensitive allele of NMD3 had decreased levels of 60S subunits at the nonpermissive temperature which resulted in the formation of half-mer polysomes. Pulse-chase analysis of rRNA biogenesis indicated that 25S rRNA was made and processed with kinetics similar to wild-type kinetics. However, the mature RNA was rapidly degraded, with a half-life of 4 min. Nmd3p fractionated as a cytoplasmic protein and sedimented in the position of free 60S subunits in sucrose gradients. These results suggest that Nmd3p is a cytoplasmic factor required for a late cytoplasmic assembly step of the 60S subunit but is not a ribosomal protein. Putative orthologs of Nmd3p exist in Drosophila, in nematodes, and in archaebacteria but not in eubacteria. The Nmd3 protein sequence does not contain readily recognizable motifs of known function. However, these proteins all have an amino-terminal domain containing four repeats of Cx2C, reminiscent of zinc-binding proteins, implicated in nucleic acid binding or protein oligomerization.
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PMID:NMD3 encodes an essential cytoplasmic protein required for stable 60S ribosomal subunits in Saccharomyces cerevisiae. 1002 25

Located at the 30 kb genomic region between complement factor B and component C4 are four ubiquitously expressed genes RD, SKI2W, DOM3Z and RP1. Besides RP1, the protein products of the other three genes each has highly conserved homologues or related proteins in lower eukaryotes, contains leucine zipper motifs for protein interaction, and plays important roles related to RNA metabolism. RD is a subunit of the negative transcription elongation factor, critical for the regulation of gene expression. It has an RNA recognition motif and 24 copies of Arg-Asp (RD) repeats. Ski2w is a nucleolar and cytoplasmic protein that has a putative RNA helicase domain. Fusion proteins of human Ski2w expressed in insect cells and bacteria have ATPase activity. The cytoplasmic protein of human Ski2w is associated with the polysomes and probably the 40S subunit of ribosomes. Ski2w is probably involved in the regulation of translation and RNA turnover. Dom3z is a nuclear protein whose yeast homologue forms a complex with an exoribonuclease. RP1 (or STK19) is a Ser/Thr nuclear protein kinase. No homologues of RP1 in lower eukaryotes have been discovered. Six polymorphic residues are present in human Ski2w and two in Dom3z. The potential roles of Ski2w and Dom3z on the clearance of degraded nuclear and cytoplasmic RNA raised their possibilities as susceptibility genes of systemic lupus erythematosus that is a disease with flawed processes in the removal of apoptotic materials.
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PMID:Features of the two gene pairs RD-SKI2W and DOM3Z-RP1 located between complement component genes factor B and C4 at the MHC class III region. 1148 1