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Functional relationships between the Saccharomyces cerevisiae cis-prenyltransferases required for dolichol biosynthesis

100%

Grabinska K., Sosinska G., Orlowski J., Swiezewska E., Berges T., Karst F., Palamarczyk G.

Acta Biochimica Polonica

2005

tom 52

nr 1

In the yeast Saccharomyces cerevisiae the RER2 and SRT1 genes encode Rer2 and Srt1 proteins with cis-prenyltransferase (cis-PT-ase) activity. Both cis-PT-ases utilize farnesyl diphosphate (FPP) as a starter for polyprenyl diphosphate (dolichol backbone) formation. The products of the Rer2 and Srt1 proteins consist of 14–17 and 18-23 isoprene units, respectively. In this work we demonstrate that deletion or overexpression of SRT1 up-regulates the activity of Rer2p and dolichol content. However, upon overexpression of SRT1, preferential synthesis of longer-chain dolichols and a decrease in the amount of the shorter species are observed. Furthermore, overexpression of the ERG20 gene (encoding farnesyl diphosphate synthase, Erg20p) induces transcription of SRT1 mRNA and increases the levels of mRNA for RER2 and DPM1 (dolichyl phosphate mannose synthase, Dpm1p). Subsequently the enzymatic activity of Rer2p and dolichol content are also increased. However, the amount of Dpm1p or its enzymatic activity remain unchanged.

Induction of the synthesis of an additional family of long-chain dolichols in the yeast Saccharomyces cerevisiae. Effect of starvation and ageing

100%

Szkopinska A., Swiezewska E., Rytka J.

Acta Biochimica Polonica

2002

tom 49

nr 3

The yeast Saccharomyces cerevisiae strain W303 synthesizes in the early logarithmic phase of growth dolichols of 14-18 isoprene residues. The analysis of the polyisoprenoids present in the stationary phase revealed an additional family which proved to be also dolichols but of 19-24 isoprene residues, constituting 39% of the total dolichols. The transfer of early logarithmic phase cells to a starvation medium lacking glucose or nitrogen resulted in the synthesis of the longer chain dolichols. The additional family of dolichols represented 13.8% and 10.3% of total dolichols in the glucose and nitrogen deficient media, respectively. The level of dolichols in yeast cells increased with the age of the cultures. Since both families of dolichols are present in stationary phase cells we postulate that the longer chain dolichols may be responsible for the physico-chemical changes in cellular membranes allowing yeast cells to adapt to nutrient deficient conditions to maintain long-term viability.

Ograniczanie wyników

2 Acta Biochimica Polonica

2 Swiezewska E.

1 Berges T.

1 Grabinska K.

1 Karst F.

1 Orlowski J.

1 Palamarczyk G.

1 Rytka J.

1 Sosinska G.

1 Szkopinska A.

1 2005

1 2002

Wyniki wyszukiwania

Functional relationships between the Saccharomyces cerevisiae cis-prenyltransferases required for dolichol biosynthesis

Induction of the synthesis of an additional family of long-chain dolichols in the yeast Saccharomyces cerevisiae. Effect of starvation and ageing