Wyniki wyszukiwania

1

Identification and characteristics of tobacco clones encoding an organellar isoform of serine acetyltransferase and a cytosolic isoform of cysteine synthase

100%

Liszewska F., Sirko A.

Biological Letters

|

2005

|

tom 42

|

nr 2 Spec.Vol.

2

Isolation of Nicotiana plumbaginifolia cDNAs encoding isoforms of serine acetyltransferase and O-acetylserine [thiol] lyase in a yeast two-hybrid system with Escherichia coli cysE and cysK genes as baits

100%

Liszewska F., Gaganidze D., Sirko A.

Acta Biochimica Polonica

|

2005

|

tom 52

|

nr 1

We applied the yeast two-hybrid system for screening of a cDNA library of Nicotiana plumbaginifolia for clones encoding plant proteins interacting with two proteins of Escherichia coli: serine acetyltransferase (SAT, the product of cysE gene) and O-acetylserine (thiol)lyase A, also termed cysteine synthase (OASTL-A, the product of cysK gene). Two plant cDNA clones were identified when using the cysE gene as a bait. These clones encode a probable cytosolic isoform of OASTL and an organellar isoform of SAT, respectively, as indicated by evolutionary trees. The second clone, encoding SAT, was identified independently also as a “prey” when using cysK as a bait. Our results reveal the possibility of applying the two-hybrid system for cloning of plant cDNAs encoding enzymes of the cysteine synthase complex in the two-hybrid system. Additionally, using genome walking sequences located upstream of the sat1 cDNA were identified. Subsequently, in silico analyses were performed aiming towards identification of the potential signal peptide and possible location of the deduced mature protein encoded by sat1.

3

Modification of non-protein thiols contents in transgenic tobacco plants producing bacterial enzymes of cysteine biosynthesis pathway

100%

Liszewska F., Blaszczyk A., Sirko A.

Acta Biochimica Polonica

|

2001

|

tom 48

|

nr 3

Conditions of achieving the maximal accumulation of sulfhydryl metabolites in the leaves of tobacco were explored. Simultaneous production of bacterial O-acetylserine (thiol)-lyase and serine acetyltransferase resulted in the increased thiols contents as compared to single transformants and controls. However, leaf discs feeding experiments differently affected thiols concentration in different plant groups and suggested that the most promising strategy to obtain plants with a high level of non-protein thiol-containing compounds might be sulfate feeding to plants overproducing serine acetyltransferase.

4

Overexpression of genes involved in phytochelatin biosynthesis in Escherichia coli: effects on growth, cadmium accumulation and thiol level

100%

Wawrzynska A., Wawrzynski A., Gaganidze D., Kopera E., Piatek K., Bal W., Sirko A.

Acta Biochimica Polonica

|

2005

|

tom 52

|

nr 1

In Escherichia coli, heterologous production of Schizosaccharomyces pombe phytochelatin synthase (PCS) along with overproduction of E. coli serine acetyltransferase (SAT) and gamma-glutamylcysteine synthase (gammaECS) was achieved and resulted in the accumulation of phytochelatins in bacterial cells. Overproduction of either gammaECS alone or simultaneous production of all three proteins in bacterial cells were accompanied by reduced growth rate in liquid cultures. Interestingly, bacteria overproducing either gammaECS or both SAT and gammaECS (with elevated level of gamma-glutamylcysteine but not of phytochelatins) were able to accumulate more cadmium per dry weight than the control. However, the most efficient cadmium accumulation was observed in bacteria with elevated levels of all three proteins: SAT, gammaECS and PCS. Therefore, “pushing” the entire pathway might be the most promising approach in modification of bacteria for potential bioremediation purposes because the level of intermediates, cysteine and glutathione, can limit the rate of production of phytochelatins. However, in such bacteria other metabolic process might become limiting for efficient growth.

Ograniczanie wyników

3 Acta Biochimica Polonica

1 Biological Letters

4 Sirko A.

3 Liszewska F.

2 Gaganidze D.

1 Bal W.

1 Blaszczyk A.

1 Kopera E.

1 Piatek K.

1 Wawrzynska A.

1 Wawrzynski A.

3 2005

1 2001

Identification and characteristics of tobacco clones encoding an organellar isoform of serine acetyltransferase and a cytosolic isoform of cysteine synthase

Isolation of Nicotiana plumbaginifolia cDNAs encoding isoforms of serine acetyltransferase and O-acetylserine [thiol] lyase in a yeast two-hybrid system with Escherichia coli cysE and cysK genes as baits

Modification of non-protein thiols contents in transgenic tobacco plants producing bacterial enzymes of cysteine biosynthesis pathway

Overexpression of genes involved in phytochelatin biosynthesis in Escherichia coli: effects on growth, cadmium accumulation and thiol level