Limits...
Isolation and characterization of a lycopene ε-cyclase gene of Chlorella (Chromochloris) zofingiensis. Regulation of the carotenogenic pathway by nitrogen and light.

Cordero BF, Couso I, Leon R, Rodriguez H, Vargas MA - Mar Drugs (2012)

Bottom Line: A single copy of Czlcy-e was found in C. zofingiensis.High irradiance stress did not increase mRNA levels of neither lycopene β-cyclase gene (lcy-b) nor lycopene ε-cyclase gene (lcy-e) as compared with low irradiance conditions, whereas the transcript levels of psy, pds, chyB and bkt genes were enhanced, nevertheless triggering the synthesis of the secondary carotenoids astaxanthin, canthaxanthin and zeaxanthin and decreasing the levels of the primary carotenoids α-carotene, lutein, violaxanthin and β-carotene.The combined effect of both high light and nitrogen starvation stresses enhanced significantly the accumulation of these carotenoids as well as the transcript levels of bkt gene, as compared with the effect of only high irradiance stress.

View Article: PubMed Central - PubMed

Affiliation: Institute of Plant Biochemistry and Photosynthesis, CIC Cartuja, University of Seville and CSIC, Avda. Americo Vespucio, n° 49, Seville 41092, Spain. baldomero@ibvf.csic.es

ABSTRACT
The isolation and characterization of the lycopene ε-cyclase gene from the green microalga Chlorella (Chromochloris) zofingiensis (Czlcy-e) was performed. This gene is involved in the formation of the carotenoids α-carotene and lutein. Czlcy-e gene encoded a polypeptide of 654 amino acids. A single copy of Czlcy-e was found in C. zofingiensis. Functional analysis by heterologous complementation in Escherichia coli showed the ability of this protein to convert lycopene to δ-carotene. In addition, the regulation of the carotenogenic pathway by light and nitrogen was also studied in C. zofingiensis. High irradiance stress did not increase mRNA levels of neither lycopene β-cyclase gene (lcy-b) nor lycopene ε-cyclase gene (lcy-e) as compared with low irradiance conditions, whereas the transcript levels of psy, pds, chyB and bkt genes were enhanced, nevertheless triggering the synthesis of the secondary carotenoids astaxanthin, canthaxanthin and zeaxanthin and decreasing the levels of the primary carotenoids α-carotene, lutein, violaxanthin and β-carotene. Nitrogen starvation per se enhanced mRNA levels of all genes considered, except lcy-e and pds, but did not trigger the synthesis of astaxanthin, canthaxanthin nor zeaxanthin. The combined effect of both high light and nitrogen starvation stresses enhanced significantly the accumulation of these carotenoids as well as the transcript levels of bkt gene, as compared with the effect of only high irradiance stress.

Show MeSH

Related in: MedlinePlus

Schematic diagram of the carotenoid biosynthetic pathway in plants and green algae. IPP, isopentenyl pyrophosphate; DMAPP, dimethylallyl pyrophosphate; GGPP, geranylgeranyl pyrophosphate; GGPPS, geranylgeranyl pyrophosphate synthase; PSY, phytoene synthase; PDS, phytoene desaturase; Z-ISO, 15-cis-ζ-carotene isomerase; ZDS, ζ-carotene isomerase; CRTISO, carotene isomerase; LCYe, lycopene ε-cyclase; LCYb, lycopene β-cyclase; P450e-CHY, cytochrome P450 ε-hydroxylase; P450b-CHY, cytochrome P450 β-hydroxylase; CHYb, carotene β-hydroxylase; BKT, β-carotene oxygenase; ZEP, zeaxanthin epoxidase; VDE, violaxanthin de-epoxidase; NSY, neoxanthin synthase.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC3475274&req=5

marinedrugs-10-02069-f001: Schematic diagram of the carotenoid biosynthetic pathway in plants and green algae. IPP, isopentenyl pyrophosphate; DMAPP, dimethylallyl pyrophosphate; GGPP, geranylgeranyl pyrophosphate; GGPPS, geranylgeranyl pyrophosphate synthase; PSY, phytoene synthase; PDS, phytoene desaturase; Z-ISO, 15-cis-ζ-carotene isomerase; ZDS, ζ-carotene isomerase; CRTISO, carotene isomerase; LCYe, lycopene ε-cyclase; LCYb, lycopene β-cyclase; P450e-CHY, cytochrome P450 ε-hydroxylase; P450b-CHY, cytochrome P450 β-hydroxylase; CHYb, carotene β-hydroxylase; BKT, β-carotene oxygenase; ZEP, zeaxanthin epoxidase; VDE, violaxanthin de-epoxidase; NSY, neoxanthin synthase.

Mentions: Carotenoids are essential pigments for all photosynthetic organisms as concerns participation in light harvesting, photoprotection, structural maintenance of pigment-protein complexes and membrane structure and fluidity [1,2,3]. In chloroplasts of plants and algae, the carotenoids precursor, geranylgeranyl pyrophosphate (GGPP), is synthesized by the action of the GGPP synthase from isopentenyl pyrophosphate and dimethylallyl pyrophosphate, which are derived from deoxyxylulose 5-phosphate pathway. The condensation of two GGPP molecules produces the first carotene, phytoene, catalyzed by phytoene synthase (PSY) (Figure 1).


Isolation and characterization of a lycopene ε-cyclase gene of Chlorella (Chromochloris) zofingiensis. Regulation of the carotenogenic pathway by nitrogen and light.

Cordero BF, Couso I, Leon R, Rodriguez H, Vargas MA - Mar Drugs (2012)

Schematic diagram of the carotenoid biosynthetic pathway in plants and green algae. IPP, isopentenyl pyrophosphate; DMAPP, dimethylallyl pyrophosphate; GGPP, geranylgeranyl pyrophosphate; GGPPS, geranylgeranyl pyrophosphate synthase; PSY, phytoene synthase; PDS, phytoene desaturase; Z-ISO, 15-cis-ζ-carotene isomerase; ZDS, ζ-carotene isomerase; CRTISO, carotene isomerase; LCYe, lycopene ε-cyclase; LCYb, lycopene β-cyclase; P450e-CHY, cytochrome P450 ε-hydroxylase; P450b-CHY, cytochrome P450 β-hydroxylase; CHYb, carotene β-hydroxylase; BKT, β-carotene oxygenase; ZEP, zeaxanthin epoxidase; VDE, violaxanthin de-epoxidase; NSY, neoxanthin synthase.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3475274&req=5

marinedrugs-10-02069-f001: Schematic diagram of the carotenoid biosynthetic pathway in plants and green algae. IPP, isopentenyl pyrophosphate; DMAPP, dimethylallyl pyrophosphate; GGPP, geranylgeranyl pyrophosphate; GGPPS, geranylgeranyl pyrophosphate synthase; PSY, phytoene synthase; PDS, phytoene desaturase; Z-ISO, 15-cis-ζ-carotene isomerase; ZDS, ζ-carotene isomerase; CRTISO, carotene isomerase; LCYe, lycopene ε-cyclase; LCYb, lycopene β-cyclase; P450e-CHY, cytochrome P450 ε-hydroxylase; P450b-CHY, cytochrome P450 β-hydroxylase; CHYb, carotene β-hydroxylase; BKT, β-carotene oxygenase; ZEP, zeaxanthin epoxidase; VDE, violaxanthin de-epoxidase; NSY, neoxanthin synthase.
Mentions: Carotenoids are essential pigments for all photosynthetic organisms as concerns participation in light harvesting, photoprotection, structural maintenance of pigment-protein complexes and membrane structure and fluidity [1,2,3]. In chloroplasts of plants and algae, the carotenoids precursor, geranylgeranyl pyrophosphate (GGPP), is synthesized by the action of the GGPP synthase from isopentenyl pyrophosphate and dimethylallyl pyrophosphate, which are derived from deoxyxylulose 5-phosphate pathway. The condensation of two GGPP molecules produces the first carotene, phytoene, catalyzed by phytoene synthase (PSY) (Figure 1).

Bottom Line: A single copy of Czlcy-e was found in C. zofingiensis.High irradiance stress did not increase mRNA levels of neither lycopene β-cyclase gene (lcy-b) nor lycopene ε-cyclase gene (lcy-e) as compared with low irradiance conditions, whereas the transcript levels of psy, pds, chyB and bkt genes were enhanced, nevertheless triggering the synthesis of the secondary carotenoids astaxanthin, canthaxanthin and zeaxanthin and decreasing the levels of the primary carotenoids α-carotene, lutein, violaxanthin and β-carotene.The combined effect of both high light and nitrogen starvation stresses enhanced significantly the accumulation of these carotenoids as well as the transcript levels of bkt gene, as compared with the effect of only high irradiance stress.

View Article: PubMed Central - PubMed

Affiliation: Institute of Plant Biochemistry and Photosynthesis, CIC Cartuja, University of Seville and CSIC, Avda. Americo Vespucio, n° 49, Seville 41092, Spain. baldomero@ibvf.csic.es

ABSTRACT
The isolation and characterization of the lycopene ε-cyclase gene from the green microalga Chlorella (Chromochloris) zofingiensis (Czlcy-e) was performed. This gene is involved in the formation of the carotenoids α-carotene and lutein. Czlcy-e gene encoded a polypeptide of 654 amino acids. A single copy of Czlcy-e was found in C. zofingiensis. Functional analysis by heterologous complementation in Escherichia coli showed the ability of this protein to convert lycopene to δ-carotene. In addition, the regulation of the carotenogenic pathway by light and nitrogen was also studied in C. zofingiensis. High irradiance stress did not increase mRNA levels of neither lycopene β-cyclase gene (lcy-b) nor lycopene ε-cyclase gene (lcy-e) as compared with low irradiance conditions, whereas the transcript levels of psy, pds, chyB and bkt genes were enhanced, nevertheless triggering the synthesis of the secondary carotenoids astaxanthin, canthaxanthin and zeaxanthin and decreasing the levels of the primary carotenoids α-carotene, lutein, violaxanthin and β-carotene. Nitrogen starvation per se enhanced mRNA levels of all genes considered, except lcy-e and pds, but did not trigger the synthesis of astaxanthin, canthaxanthin nor zeaxanthin. The combined effect of both high light and nitrogen starvation stresses enhanced significantly the accumulation of these carotenoids as well as the transcript levels of bkt gene, as compared with the effect of only high irradiance stress.

Show MeSH
Related in: MedlinePlus