pyrophosphate and inositol-2-monophosphate

Inositol diphosphates (PP-IPs), also known as inositol pyrophosphates, are high-energy cellular signaling codes involved in nutrient and regulatory responses. We report that the evolutionarily conserved gene product, Vip1, possesses autonomous kinase and pyrophosphatase domains capable of synthesis and destruction of D-1 PP-IPs. Our studies provide atomic-resolution structures of the PP-IP products and unequivocally define that the Vip1 gene product is a highly selective 1-kinase and 1-pyrophosphatase enzyme whose activities arise through distinct active sites. Kinetic analyses of kinase and pyrophosphatase parameters are consistent with Vip1 evolving to modulate levels of 1-IP

Topics: Diphosphates; Inositol Phosphates; Kinetics; Phosphorylation; Phosphotransferases (Phosphate Group Acceptor); Pyrophosphatases; Saccharomyces cerevisiae; Signal Transduction