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Nip1p Associates with 40 S Ribosomes and the Prt1p Subunit of Eukaryotic Initiation Factor 3 and Is Required for Efficient Translation Initiation*
- Source :
- Journal of Biological Chemistry; September 1998, Vol. 273 Issue: 36 p23485-23494, 10p
- Publication Year :
- 1998
-
Abstract
- Nip1p is an essential Saccharomyces cerevisiaeprotein that was identified in a screen for temperature conditional (ts) mutants exhibiting defects in nuclear transport. New results indicate that Nip1p has a primary role in translation initiation. Polysome profiles indicate that cells depleted of Nip1p and nip1-1cells are defective in translation initiation, a conclusion that is supported by a reduced rate of protein synthesis in Nip1p-depleted cells. Nip1p cosediments with free 40 S ribosomal subunits and polysomal preinitiation complexes, but not with free or elongating 80 S ribosomes or 60 S subunits. Nip1p can be isolated in an about 670-kDa complex containing polyhistidine-tagged Prt1p, a subunit of translation initiation factor 3, by binding to Ni2+-NTA-agarose beads in a manner completely dependent on the tagged form of Prt1p. The nip1-1ts growth defect was suppressed by the deletion of the ribosomal protein, RPL46. Also, nip1-1mutant cells are hypersensitive to paromomycin. These results suggest that Nip1p is a subunit of eukaryotic initiation factor 3 required for efficient translation initiation.
Details
- Language :
- English
- ISSN :
- 00219258 and 1083351X
- Volume :
- 273
- Issue :
- 36
- Database :
- Supplemental Index
- Journal :
- Journal of Biological Chemistry
- Publication Type :
- Periodical
- Accession number :
- ejs55819690
- Full Text :
- https://doi.org/10.1074/jbc.273.36.23485