; R o o t E n t r y F p`D @ C o m p O b j b W o r d D o c u m e n t O b j e c t P o o l k?_D k?_D 4 @ & ' ( ) * + , - . / 0 F Microsoft Word 6.0 Document MSWordDoc Word.Document.6 ; Abstract 9505980 Chang Phosphorylation/dephosphorylation reactions are important for mediating cell response to environmental signals and regulating various cellular functions. This grant is examining the role of phosphorylation in yeast, specifically the plasma membrane (H+( encoded by the PMA1 gene, which has a critical physiological role and is essential for cell viability. The activity of Pma1 (the protein encoded by this gene), is altered by environmental factors including glucose metabolism. This investigator has shown that Pma1 activation which occurs in response to glucose in the medium, is mediated by site-specific dephosphorylation which occurs at the plasma membrane. During its transit through the secretory path, Pma1 is constitutively phosphorylated on serine and threonine residues. This investigator will identify the specific kinases that interact with specific domains of Pma1, using the yeast 2 hybrid system and peptide microsequencing of proteins that co-immunoprecipitate with Pma1. Mutants defective for glucose mediated a activation will be used to identify the gluc ose regulated phosphorylation sites. %%% These experiments will elucidate the signal transduction mechanisms which are used by yeast to respond to environmental changes and to fulfill physiological needs. They will also provide information on phosphorylation in signal transduction and regulation. *** ; Oh +' 0 $ H l D h S u m m a r y I n f o r m a t i o n ( % R:WWUSERTEMPLATENORMAL.DOT Abstract Una Solomon Una Solomon @ ,LD @ @ ,LD @ Microsoft Word 6.0 2 ; ; e = e l l l l l l l 1 ~ . T a 2 l l l l l ~ l l l l ~ Abstract 9505980 Chang Phosphorylation/dephosphorylation reactions are important for mediating cell response to environmental signals and regulating various cellular functions. This grant is examining the role of phosphorylation in yeast, specifically the plasma membrane (H+( encoded by the PMA1 gene, which has a critical physiological role and is essential for cell viability. The activity of Pma1 (the protein encoded by this gene), is altered by environmental factors including glucose metabolism. This investigator has shown that Pma1 activation which occurs in response to glucose in the medium, is mediated by site-specific dephosphorylation which occurs at the plasma membrane. During its transit through the secretory path, Pma1 is constitutively phosphorylated on serine and threonine residues. This investigator will identify the specific kinases that interact with specific domains of Pma1, using the yeast 2 hybrid system and peptide microsequencing of proteins that co-immunoprecipitate with Pma1. Mutants defective for glucose mediated a activation wi
