The three yeast A kinases have specific signaling functions in pseudohyphal growth.
The three yeast A kinase catalytic subunit isoforms are redundant for viability. We demonstrate that they have dramatically different roles in pseudohyphal development: Tpk2 is essential, whereas Tpk3 inhibits. Tpk1 has no discernible effect. Two-hybrid analysis identified the transcription factor Sfl1 as a protein that interacts specifically with Tpk2, but not Tpk1 or Tpk3. Deletion of SFL1 enhances pseudohyphal and invasive growth. Flo11, a cell surface flocculin required for pseudohyphal development, is transcriptionally regulated by Tpk2 and Sfl1. Genetic evidence indicates that Tpk2 acts upstream of Sfl1 in the regulation of Flo11.
Robertson
L S
LS
Whitehead Institute for Biomedical Research, Nine Cambridge Center, Cambridge, MA 02142, USA.
Fink
G R
GR
D017868:Cyclic AMP-Dependent Protein Kinases / Q000502:physiology*; D015971:Gene Expression Regulation, Enzymologic; D015966:Gene Expression Regulation, Fungal; D009154:Mutation; D012441:Saccharomyces cerevisiae / Q000201:enzymology* / Q000235:genetics / Q000254:growth & development*; D015398:Signal Transduction
D017868:Cyclic AMP-Dependent Protein Kinases