« Previous AbstractDiel Rhythmicity of Field Responses to Synthetic Pheromone Lures in the Pine Sawyer Monochamus saltuarius    Next AbstractIdentification and Field Bioassay of Rusicada privata (Lepidoptera: Erebidae) Sex Pheromone »

Biomolecules

Title:		Cla4p Kinase Activity Is Down-Regulated by Fus3p during Yeast Mating
Author(s):		Kim J; Rose MD;
Address:		"Department of Molecular Biology, Princeton University, Princeton, NJ 08544, USA. Department of Biology, Georgetown University, Washington, DC 20057, USA"
Journal Title:		Biomolecules
Year:		2022
Volume:		20220418
Issue:		4
Page Number:		-
DOI:		10.3390/biom12040598
ISSN/ISBN:		2218-273X (Electronic) 2218-273X (Linking)
Abstract:		"In Saccharomyces cerevisiae, the p21-activated kinase Cla4p regulates polarized morphogenesis and cytokinesis. However, it remains unknown how Cla4p kinase activity is regulated. After pheromone exposure, yeast cells temporally separate the mitotic and mating programs by sequestering Fus2p in the nucleus until cell cycle completion, after which Fus2p exits to facilitate cell fusion. Previously, we showed that sequestration is regulated by two opposing protein kinases, Cla4p and Fus3p. Phosphorylation of Fus2p-S67 by Cla4p promotes nuclear localization by both activating nuclear import and blocking export. During mating, phosphorylation of Fus2p-S85 and Fus2p-S100 by Fus3p promotes nuclear export and blocks import. Here, we find that Cla4p kinase activity is itself down-regulated during mating. Pheromone exposure causes Cla4p hyper-phosphorylation and reduced Fus2p-S67 phosphorylation, dependent on Fus3p. Multiple phosphorylation sites in Cla4p are mating- and/or Fus3p-specific. Of these, Cla4p-S186 phosphorylation reduced the kinase activity of Cla4p, in vitro. A phosphomimetic cla4-S186E mutation caused a strong reduction in Fus2p-S67 phosphorylation and nuclear localization, in vivo. More generally, a non-phosphorylatable mutation, cla4-S186A, caused failure to maintain pheromone arrest and delayed formation of the mating-specific septin morphology. Thus, as cells enter the mating pathway, Fus3p counteracts Cla4p kinase activity to allow proper mating differentiation"
Keywords:		Cell Nucleus/metabolism Mitogen-Activated Protein Kinases Pheromones/metabolism Phosphorylation Protein Serine-Threonine Kinases *Saccharomyces cerevisiae/metabolism *Saccharomyces cerevisiae Proteins/genetics/metabolism MAP-kinase PAK-kinase Saccharomyce;
Notes:		"MedlineKim, Junwon Rose, Mark D eng R01 GM037739/GM/NIGMS NIH HHS/ R35 GM126998/GM/NIGMS NIH HHS/ GM037739/NH/NIH HHS/ GM126998/NH/NIH HHS/ Switzerland 2022/04/24 Biomolecules. 2022 Apr 18; 12(4):598. doi: 10.3390/biom12040598"