Reference - PMID:12972434 - Cpc2/RACK1 is a ribosome-associated protein that promotes efficient translation in Schizosaccharomyces pombe.
Reference summary
- PubMed ID
- PMID:12972434
- Title
- Cpc2/RACK1 is a ribosome-associated protein that promotes efficient translation in Schizosaccharomyces pombe.
- Authors
- Shor B, Calaycay J, Rushbrook J, McLeod M
- Citation
- J Biol Chem 2003 Dec 05;278(49):49119-28
- Publication year
- 2003
- Abstract
- Cpc2/RACK1 is a highly conserved WD domain protein found in all eucaryotes. Cpc2/RACK1 functions on mammalian signal transduction pathways most notably as an adaptor protein for the betaII protein kinase C isozyme. In single cell eucaryotes, Cpc2/RACK1 regulates growth, differentiation, and entry into G0 stationary phase. The exact biochemical function of Cpc2/RACK1 is unknown. Here, we provide evidence that Cpc2 is associated with the ribosome. Using immunoaffinity purification, we isolated ribosomal proteins in association with Cpc2/RACK1. Polysome and ribosomal subunit analysis using velocity gradient centrifugation of cell lysates demonstrated that Cpc2 co-sediments with the 40 S ribosomal subunit and with polysomes. Conditions known to disrupt ribosome structure alter sedimentation of the ribosome and of Cpc2/RACK1 coordinately. Loss of cpc2 does not dramatically alter the rate of cellular protein synthesis but causes a decrease in the steady state level of numerous proteins, some of which regulate methionine metabolism. Whereas real time PCR analysis demonstrated that transcriptional mechanisms are responsible for down-regulation of some of these proteins, one protein, ribosomal protein L25, is probably regulated at the level of translation.
