Phosphorylation of glucosamine-6-phosphate synthase is important but not essential for germination and mycelial growth of Candida albicans.
A site-directed mutagenesis of the GFA1 gene encoding Candida albicans glucosamine-6-phosphate (GlcN-6-P) synthase afforded its GFA1S208A version. A product of the modified gene, lacking the putative phosphorylation site for protein kinase A (PKA), exhibited all the basic properties identical to those of the wild-type enzyme but was no longer a substrate for PKA. Comparison of the C. albicans Deltagfa1/GFA1 and Deltagfa1/GFA1S208A cells, grown under conditions stimulating yeast-to-mycelia transformation, revealed that the latter demonstrated lower GlcN-6-P synthase specific activity, decreased chitin content and formed much fewer mycelial forms. All these findings, as well as the observed effects of specific inhibitors of protein kinases, suggest that a loss of the possibility of GlcN-6-P synthase phosphorylation by PKA strongly reduces but not completely eliminates the germinative response of C. albicans cells.
Gabriel
Iwona
I
Department of Pharmaceutical Technology and Biochemistry, Gdańsk University of Technology, 11/12 Narutowicza St., 80-952 Gdańsk, Poland.
Olchowy
Jarosław
J
Stanisławska-Sachadyn
Anna
A
Mio
Toshiyuki
T
Kur
Józef
J
Milewski
Sławomir
S
D002176:Candida albicans / Q000166:cytology / Q000201:enzymology* / Q000254:growth & development*; D002455:Cell Division; D002686:Chitin / Q000378:metabolism; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005656:Fungal Proteins / Q000235:genetics / Q000378:metabolism* / Q000502:physiology; D005945:Glutamine-Fructose-6-Phosphate Transaminase (Isomerizing) / Q000235:genetics / Q000378:metabolism* / Q000502:physiology; D016297:Mutagenesis, Site-Directed; D025282:Mycelium / Q000166:cytology; D010766:Phosphorylation; D011494:Protein Kinases / Q000378:metabolism; D014170:Transformation, Genetic
D004791:Enzyme Inhibitors; D005656:Fungal Proteins; D002686:Chitin; D005945:Glutamine-Fructose-6-Phosphate Transaminase (Isomerizing); D011494:Protein Kinases