Using yeast to uncover the regulation of protein kinase Cδ by ceramide.
The regulation of protein kinase C (PKC) isoforms by ceramide is still controversial. In this work, the yeast Saccharomyces cerevisiae was used as a model to elucidate the effect of ceramide on the activity of mammalian PKC isoforms. For that, isc1Δ cells, with a deletion in the pathway for ceramide production by hydrolysis of complex sphingolipids, individually expressing mammalian PKCα, δ and ζ were used. Contrary to PKCα and ζ, expression of PKCδ in isc1Δ cells exhibited a similar phenotype to that observed with wild-type yeast cells expressing PKCδ treated with a PKC activator, as phorbol 12-myristate 13-acetate (PMA), specifically a growth inhibition associated with a G2/M cell cycle arrest. Interestingly, in isc1Δ yeast cells expressing PKCδ this phenotype was completely abrogated in the presence of exogenous ceramide. Moreover, using a yeast-based assay previously developed for the screening of PKC inhibitors, it was also shown that, like the known PKC inhibitor NPC 15437, ceramide reduced the PMA-induced growth inhibition, supporting an inhibitory effect of ceramide on PKCδ. Altogether, these results may indicate that ceramide distinctly interfere with the activity of PKCα, δ and ζ. Most importantly, they showed that ceramide is an inhibitor of PKCδ.
REQUIMTE, Laboratório de Microbiologia, Departamento de Ciências Biológicas, Faculdade de Farmácia, Universidade do Porto, Porto, Portugal.
Cláudia
C
Bessa
Clara
C
Pereira
Mariana
M
Leão
Cláudia
C
Maciel
Sara
S
Gomes
Jorge
J
Gonçalves
Manuela
M
Corte-Real
Vítor
V
Costa
Lucília
L
Saraiva
D002453:Cell Cycle / Q000187:drug effects; D002518:Ceramides / Q000378:metabolism*; D004791:Enzyme Inhibitors / Q000378:metabolism; D020033:Protein Isoforms / Q000235:genetics / Q000378:metabolism; D011493:Protein Kinase C / Q000235:genetics / Q000378:metabolism*; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000201:enzymology* / Q000235:genetics / Q000502:physiology*
D002518:Ceramides; D004791:Enzyme Inhibitors; D020033:Protein Isoforms; D011994:Recombinant Proteins; D011493:Protein Kinase C
Saccharomyces cerevisiae; ceramide; protein kinase Cδ