XXII. BIOCHEMICKÝ ZJAZD - Jesseniova lekárska fakulta

Plenary lectures
IDENTIFICATION OF PHOSPHATIDYLGLYCEROL SPECIFIC PHOSPHOLIPASE
C IN YEAST SACCHarOMYCES CEREVISIAE
Mária Balážová and Peter Griač
Institute of Animal Biochemistry and Genetics SAV, Ivanka pri Dunaji
Phosphatidylglycerol (PG) is a metabolic precursor to the unique anionic mitochondrial
phospholipid, cardiolipin (CL). CL and PG are phospholipids with important functions in
promoting cell growth, anaerobic metabolism, mitochondrial functions and biogenesis.
Considering their important role in eukaryotic cell physiology, little is known about the
mechanisms by which PG membrane composition is controlled.
Product of the open reading frame YPL206c, Pgc1p, of the yeast Saccharomyces cerevisiae
is homologous to bacterial and mammalian glycerophosphodiester phosphodiesterases.
Deletion of PGC1 causes accumulation of PG, which was evident especially under the
conditions of inositol limitation. To test if the product of PGC1 has an effect on degradation
of PG, an in vitro assay was devised. Data obtained from this assay indicated that
in the strain without Pgc1p, production of NBD-diacylglycerol (NBD-DAG) is significantly
decreased compared to the wild type strain. In addition, NBD-DAG production was highly
increased in the strain with overexpression of the Pgc1p. Two localizations of GST tagged-
Pgs1p were observed: mitochondrion and lipid particles. However, in vitro phospholipase
C activity of Pgc1 protein was detected only using mitochondrial protein extract. Based
on these results we suggest that the product of YPL206c encodes mitochondrial PG
specific phospholipase C (Pgc1p) involved in regulation of PG levels.
Acknowledgement: Work was supported by LPP-0291-09 and VVCE-0064-07 grants.
36 XXII. Biochemistry Congress, Martin