Pop3p is essential for the activity of the RNase MRP and RNase P ribonucleoproteins in vivo.
In: EMBO Journal, Jg. 16 (1997-01-15), Heft 2, S. 417-429
academicJournal
Zugriff:
RNase MRP is a ribonucleoprotein (RNP) particle which is involved in the processing of pre-rRNA at site A3 in internal transcribed spacer 1. Although RNase MRP has been analysed functionally, the structure and composition of the particle are not well characterized. A genetic screen for mutants which are synthetically lethal (s1) with a temperature-sensitive (ts) mutation in the RNA component of RNase MRP (rrp2-1) identified an essential gene, POP3, which encodes a basic protein of 22.6 kDa predicted molecular weight. Over-expression of Pop3p fully suppresses the ts growth phenotype of the rrp2-1 allele at 34°C and gives partial suppression at 37°C. Depletion of Pop3p in vivo results in a phenotype characteristic of the loss of RNase MRP activity; A3 cleavage is inhibited, leading to under-accumulation of the short form of the 5.8S rRNA (5.8Ss) and formation of all aberrant 5.8S rRNA precursor which is 5′-extended to site A2. Pop3p depletion also inhibits pre-tRNA processing; tRNA primary transcripts accumulate, as well as spliced but 5′-and 3′-unprocessed pre-tRNAs. The Pop3p depletion phenotype resembles those previously described for mutations in components of RNase MRP and RNase P (rrp2-1, rpr1-1 and pop1-1). lmmunoprecipitation of epitope-tagged Pop3p co-precipitates the RNA components of both RNase MRP and RNase E Pop3p is, therefore, a common component of both RNPs and is required for their enzymatic functions in vivo. The ubiquitous RNase P RNP, which has a single protein component in Bacteria and Archaea, requires at least two protein subunits for its function in eukaryotic cells. [ABSTRACT FROM AUTHOR]
Titel: |
Pop3p is essential for the activity of the RNase MRP and RNase P ribonucleoproteins in vivo.
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Autor/in / Beteiligte Person: | Dichtl, Bernhard ; Tollervey, David |
Zeitschrift: | EMBO Journal, Jg. 16 (1997-01-15), Heft 2, S. 417-429 |
Veröffentlichung: | 1997 |
Medientyp: | academicJournal |
ISSN: | 0261-4189 (print) |
DOI: | 10.1093/emboj/16.2.417 |
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