Alterations of O-glycosylation, cell wall, and mitochondrial metabolism in Kluyveromyces lactis cells defective in KlPmr1p, the Golgi Ca(2+)-ATPase.
In yeast the P-type Ca(2+)-ATPase of the Golgi apparatus, Pmr1p, is the most important player in calcium homeostasis. In Kluyveromyces lactis KlPMR1 inactivation leads to pleiotropic phenotypes, including reduced N-glycosylation and altered cell wall morphogenesis. To study the physiology of K. lactis when KlPMR1 was inactivated microarrays containing all Saccharomyces cerevisiae coding sequences were utilized. Alterations in O-glycosylation, consistent with the repression of KlPMT2, were found and a terminal N-acetylglucosamine in the O-glycans was identified. Klpmr1Delta cells showed increased expression of PIRs, proteins involved in cell wall maintenance, suggesting that responses to cell wall weakening take place in K. lactis. We found over-expression of KlPDA1 and KlACS2 genes involved in the Acetyl-CoA synthesis and down-regulation of KlIDP1, KlACO1, and KlSDH2 genes involved in respiratory metabolism. Increases in oxygen consumption and succinate dehydrogenase activity were also observed in mutant cells. The described approach highlighted the unexpected involvement of KlPMR1 in energy-yielding processes.
Farina
Francesca
F
Department of Developmental and Cell Biology, University of Rome La Sapienza, Piazza Aldo Moro 5, 00185 Rome, Italy.
Uccelletti
Daniela
D
Goffrini
Paola
P
Butow
Ronald A
RA
Abeijon
Claudia
C
Palleschi
Claudio
C
D000117:Acetylglucosamine / Q000378:metabolism; D000252:Calcium-Transporting ATPases / Q000172:deficiency* / Q000235:genetics / Q000378:metabolism*; D002240:Carbohydrate Sequence; D002473:Cell Wall / Q000378:metabolism; D005656:Fungal Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D015870:Gene Expression; D005800:Genes, Fungal / Q000235:genetics; D006031:Glycosylation; D006056:Golgi Apparatus / Q000201:enzymology*; D007716:Kluyveromyces / Q000166:cytology / Q000201:enzymology* / Q000235:genetics / Q000254:growth & development; D008928:Mitochondria / Q000378:metabolism*; D008969:Molecular Sequence Data; D016366:Open Reading Frames / Q000235:genetics; D012333:RNA, Messenger / Q000096:biosynthesis; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism; D013385:Succinate Dehydrogenase / Q000378:metabolism
D005656:Fungal Proteins; D012333:RNA, Messenger; D011994:Recombinant Proteins; D013385:Succinate Dehydrogenase; D000252:Calcium-Transporting ATPases; D000117:Acetylglucosamine