Dual-specificity protein phosphatase Yvh1p, which is required for vegetative growth and sporulation, interacts with yeast pescadillo homolog in Saccharomyces cerevisiae

The Saccharomyces cerevisiae dual-specificity protein phosphatase Yvh1p, id entified as vaccinia VH1 homolog, regulates cell growth, sporulation, and g lycogen accumulation. Transcription of YVH1 is induced by lowering temperat ure and nitrogen starvation. Using the yeast two-hybrid system, we searched for Yvh1p-interacting proteins, including substrates and regulatory subuni ts of Yvh1p. Two clones were identified encoding a segment of YPH1 (yeast p escadillo homolog), which is essential for cell cycle progression in yeast. Deletion analysis revealed that the catalytic domain of Yvh1p and the BRCT domain of Yph1p are sufficient for this interaction. We found that the mul ticopy of YPH1 not only suppressed slow growth but also decreased IME2 expr ession in the yvh1 disruptant. These observations indicate that Yph1p plays a role in sporulation in addition to cell cycle progression, and is a cand idate for a substrate or a regulatory subunit of Yvh1p. (C) 2001 Elsevier S cience.