Cgr1p, a novel nucleolar protein encoded by Saccharomyces cerevisiae Orf YGL0292w

Saccharomyces cerevisiae open reading frame (ORF) YGL029w (CGR1) encodes a small hydrophilic protein of unknown function. To investigate the role of t his gene, we have determined the intracellular localization of the encoded product and examined the effects of Cgr1p depletion on cell growth. Tagging Cgr1p with the green fluorescent protein (GFP) or the myc epitope showed f ocal accumulation of the fusion protein in the yeast nucleolus, and this lo calization overlapped with the distribution of the nucleolar protein Nop1p. Cells depleted of CGR1 mRNA were growth impaired and hypersensitive to the translational inhibitor paromomycin, and this phenotype was complemented b y episomal expression of the CGR1-GFP fusion gene. These results identify C gr1p as a novel component of the yeast nucleolus and suggest a potential ro le in ribosome biogenesis.