Ammonium permease-based sensing mechanism for rapid ammonium activation of the protein kinase A pathway in yeast.

摘要: In the yeast Saccharomyces cerevisiae starvation for nitrogen on a glucose-containing medium causes entrance into G0 and downregulation of all targets PKA pathway. Re-addition source in presence glucose rapid activation trehalase other targets. Trehalase upon ammonium re-supplementation is dependent activity, but not its regulatory subunit nor it associated with an increase cAMP. nitrogen-starved cells, transport are most active strains expressing either Mep2 or Mep1 permease, as opposed to Mep3. The non-metabolizable analogue, methylamine, also triggers when transported by taken up diffusion. Inhibition incorporation metabolism did prevent signalling. Extensive site-directed mutagenesis showed that signalling were generally affected similar way, although they could be separated partially specific mutations. Our results suggest permease-based sensing mechanism Mutagenesis Asn246 Ala abolished methylamine had no effect ammonium. plant AtAmt1;1, AtAmt1;2, AtAmt1;3 AtAmt2 transporters sustained different extents. Specific mutations differently from induction pseudohyphal differentiation. We show Mep permease involvement control their role haploid invasive growth, which sustains inhibits, way independent level medium.