title: The 14-3-3 proteins encoded by the BMH1 and BMH2 genes are essential in the yeast Saccharomyces cerevisiae and can be replaced by a plant homologue.
abstract: The 14-3-3 proteins comprise a family of highly conserved acidic proteins. Several activities have been ascribed to these proteins, including activation of tyrosine and tryptophan hydroxylases in the presence of calcium/calmodulin-dependent protein kinase II, regulation of protein kinase C, phospholipase A2 activity, stimulation of exocytosis and activation of bacterial exoenzyme S (ExoS) during ADP-ribosylation of host proteins. In addition, a plant 14-3-3 protein is present in a G-box DNA/protein-binding complex. Previously, we isolated the BMH1 gene from Saccharomyces cerevisiae encoding a putative 14-3-3 protein. Using the polymerase chain reaction method, we have isolated a second yeast gene encoding a 14-3-3 protein (BMH2). While disruption of either BMH1 or BMH2 alone had little effect, it was impossible to obtain viable cells with both genes disrupted. The cDNA encoding a plant 14-3-3 protein under the control of the inducible GAL1 promoter complemented the double disruption. Transfer of the complemented double disruptant to a medium with glucose resulted in the appearance of a high percentage of large budded cells. After prolonged incubation, these cells became enlarged with irregular buds and chains of cells defective in cell-cell separation became visible. These results suggest an essential role of the 14-3-3 proteins, possibly at a later stage of the yeast cell cycle.
authors.affiliation: Institute of Molecular Plant Sciences, Leiden University, The Netherlands.
authors.forename: G P
authors.initials: GP
authors.lastname: van Heusden
authors.forename: D J
authors.initials: DJ
authors.lastname: Griffiths
authors.forename: J C
authors.initials: JC
authors.lastname: Ford
authors.forename: T F
authors.initials: TF
authors.lastname: Chin-A-Woeng
authors.forename: P A
authors.initials: PA
authors.lastname: Schrader
authors.forename: A M
authors.initials: AM
authors.lastname: Carr
authors.forename: H Y
authors.initials: HY
authors.lastname: Steensma
mesh_terms: D048948:14-3-3 Proteins; D000595:Amino Acid Sequence; D001483:Base Sequence; D003001:Cloning, Molecular; D008969:Molecular Sequence Data; D010944:Plants / Q000235:genetics; D011506:Proteins / Q000235:genetics*; D012441:Saccharomyces cerevisiae / Q000235:genetics*; D016415:Sequence Alignment; D014446:Tyrosine 3-Monooxygenase
chemical_list: D048948:14-3-3 Proteins; D011506:Proteins; D014446:Tyrosine 3-Monooxygenase