An upstream regulator and downstream target of phospholipase D1 activity during pheromone response in Saccharomyces cerevisiae.
Phospholipase D1 (PLD1), which is the product of the SPO14 gene, has been shown to play a role in the process of polarized cell growth (PCG) during the pheromone response in Saccharomyces cerevisiae. PLD1 hydrolyzes phosphatidylcholine to produce phosphatidic acid (PA) and a free choline headgroup. This study investigated the interactions of PLD1 and PA with two proteins known to be involved in the cellular signaling leading to PCG in yeast, the small GTPase Cdc42p and the PAK family kinase Ste20p. Constitutively activated Cdc42p stimulates PLD1 activity. Protein-lipid binding blots confirmed the specific binding of Ste20p to the PLD1 product, PA. Finally, kinase activity assays provided evidence for the stimulation of Ste20p by PA. These findings highlight the important interactions among PLD1, Cdc42p and Ste20p during PCG in S. cerevisiae.
Harkins
April L
AL
Department of Microbiology and Immunology, Medical University of South Carolina, Charleston, SC, USA. april.harkins@marquette.edu
London
Steven D
SD
Dolan
Joseph W
JW
D017353:Gene Deletion; D047908:Intracellular Signaling Peptides and Proteins; D020930:MAP Kinase Kinase Kinases; D008954:Models, Biological; D010675:Pheromones / Q000378:metabolism*; D010712:Phosphatidic Acids / Q000378:metabolism; D010739:Phospholipase D / Q000378:metabolism*; D011485:Protein Binding; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism*; D012441:Saccharomyces cerevisiae / Q000254:growth & development / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins / Q000378:metabolism*; D020846:cdc42 GTP-Binding Protein, Saccharomyces cerevisiae / Q000378:metabolism*
D047908:Intracellular Signaling Peptides and Proteins; D010675:Pheromones; D010712:Phosphatidic Acids; D029701:Saccharomyces cerevisiae Proteins; D017346:Protein Serine-Threonine Kinases; D020930:MAP Kinase Kinase Kinases; C078754:STE20 protein, S cerevisiae; D010739:Phospholipase D; C471177:SPO14 protein, S cerevisiae; D020846:cdc42 GTP-Binding Protein, Saccharomyces cerevisiae