Dual-Specificity Protein Phosphatase Yvh1p, Which Is Required for Vegetative Growth and Sporulation, Interacts with Yeast Pescadillo Homolog in Saccharomyces cerevisiae

A Mutant Plasma Membrane Protein Is Stabilized Upon Loss of Yvh1, a Novel Ribosome Assembly Factor

“…Previously, Yvh1 was found associated with purified 60S preribosomal particles (Nissan et al 2002) and was also reported to interact by two-hybrid assay with the essential ribosome assembly factor Nop7 (Sakumoto et al 2001). To test whether Yvh1 plays a role in ribosome assembly, the polysome profile of yvh1D cells was analyzed by sucrose density gradients.…”

“…Yvh1 is associated with cytoplasmic 60S preribosomal particles (Nissan et al 2002). By twohybrid assay, Yvh1 interacts with Nop7, a ribosome assembly factor and constituent of several different preribosomal particles (Sakumoto et al 2001). Another physical interaction study reports Yvh1 interaction with Tif6, Rei1, and Lsg1, all factors involved in 60S ribosome biogenesis (Tarassov et al 2008).…”

Yeast Pescadillo is required for multiple activities during 60S ribosomal subunit synthesis

“…Pescadillo was isolated as a mutation affecting embryonic development (Allende et al+, 1996) and a mutant allele of the yeast gene resulted in growth arrest in G2 (Kinoshita et al+, 2001), consistent with a specific defect in cell-cycle progression+ Yeast Yhp1p/Nop7p is also reported to interact with Yvh1p (Sakumoto et al+, 2001), a protein-tyrosine phosphatase with a postulated role in the regulation of sporulation and meiosis+ There are clear precedents for proteins that function both in cell-cycle progression and ribosome synthesis+ Exit from mitosis in budding yeast requires a group of proteins, including the phosphatase Cdc14p, which down-regulate cyclin-dependent kinase activity+ Cdc14p is sequestered in the nucleolus in the RENT (regulator of nucleolar silencing and telophase) complex with Sir2p and Net1p, which serves to anchor the complex (Shou et al+, 1999)+ In addition, Net1p is required for the maintenance of normal nucleolar structure and its binding stimulates RNA polymerase I (Shou et al+, 1999(Shou et al+, , 2001)+ These nucleolus-specific functions of Net1p can be separated genetically from its cell-cycle functions in the RENT complex+ In human cells, the nucleolar p14/ARF protein binds and sequesters the negative regulator of p53 activity, Mdm2 (Tao & Levine, 1999;Weber et al+, 1999;Zhang & Xiong, 1999)+ Free Mdm2 ubiquitinates p53 and transports it to the cytoplasm where it is degraded by the proteosome (Fuchs et al+, 1998;Geyer et al+, 2000), and the nucleolar sequestration of Mdm2 contributes to the inhibition of this activity by ARF+ Mouse Pescadillo was identified by its up-regulation in cells lacking p53 (Kinoshita et al+, 2001), but other interactions with the p53 system have not been reported+…”

The dual-specificity phosphatase hYVH1 (DUSP12) is a novel modulator of cellular DNA content

“…8 A yeast two-hybrid screen identified YPH1 (yeast pescadillo homolog, Nop7) as a yeast YVH1-interacting partner. 9 Nop7 is required for multiple activities during 60S ribosomal synthesis. 10 YVH1 was also recently identified as a 60S transacting factor in a mass spectrometry (MS)-based analysis of pre-60S particles.…”