Disease relevance of YVH1

• The Saccharomyces cerevisiae dual-specificity protein phosphatase Yvh1p, identified as vaccinia VH1 homolog, regulates cell growth, sporulation, and glycogen accumulation [1].
• The human YVH1 gene is located on chromosome 1q21-q22, which falls in a region amplified in human liposarcomas [2].

High impact information on YVH1

• Human YVH1 is the first protein-tyrosine phosphatase that contains and is regulated by a zinc finger domain [2].
• A catalytically inactive variant of yvh1 (C117S) and a DNA fragment encoding only the Yvh1p C-terminal 159 amino acids (which completely lacks the phosphatase domain) complement all three phenotypes as well as the wild-type allele; no complementation occurs with a fragment encoding only the C-terminal 74 amino acids [3].
• Yvh1p, a dual-specific protein phosphatase induced specifically by nitrogen starvation, regulates cell growth as well as initiation and completion of sporulation [3].
• The dual-specificity protein phosphatase Yvh1p regulates sporulation, growth, and glycogen accumulation independently of catalytic activity in Saccharomyces cerevisiae via the cyclic AMP-dependent protein kinase cascade [3].
• In addition, reporter gene expression supported by a DRR2 promoter fragment, containing two stress response elements known to respond to cAMP-protein kinase A, decreases in a yvh1 disruption mutant [3].

Biological context of YVH1

• These data suggest that the YVH1 and PTP2 encoded phosphatases likely participate in the control network regulating meiosis and sporulation [4].
• Starvation for nitrogen in the absence of a fermentable carbon source causes diploid Saccharomyces cerevisiae cells to leave vegetative growth, enter meiosis, and sporulare; the former nutritional condition also induces expression of the YVH1 gene that encodes a protein phosphatase [4].
• These observations indicate that Yph1p plays a role in sporulation in addition to cell cycle progression, and is a candidate for a substrate or a regulatory subunit of Yvh1p [1].
• These results demonstrate the specificity of the yvh1 disruption phenotype [4].
• We found that expression of the IME2 gene, encoding a protein kinase homologue required for meiosis- and sporulation-specific gene expression, is decreased in a yvh1 disrupted strain [4].

Regulatory relationships of YVH1

• Our data confirm that pseudohyphal growth occurs gratuitously in sup70-65 mutants cultured in nitrogen-rich medium at 30 degrees C. However, we find neither any defect in NCR in the sup70-65 mutant nor any alteration in the control of YVH1 expression, which has been previously shown to be specifically induced by nitrogen starvation [5].

Other interactions of YVH1

• The dual-specificity protein phosphatase Yvh1p acts upstream of the protein kinase mck1p in promoting spore development in Saccharomyces cerevisiae [6].
• Sporulation of a homozygous yvh1 disruption mutant was delayed and less efficient overall compared to an isogenic wild-type strain, a result which correlates with decreased IME1 and IME2 gene expression [4].
• Deletion analysis revealed that the catalytic domain of Yvh1p and the BRCT domain of Yph1p are sufficient for this interaction [1].
• In an attempt to analyse the function of Yvh1p phosphatase, the complete ORFs of both alleles were deleted by replacement with hph200-URA3-hph200 and ARG4 [7].
• Four double disruptants exhibited synthetic phenotypes in addition to eight single ones: the pph21 pph22 double disruptant showed slow growth on complete medium, as did the sit4 and yvh1 single ones [8].

References