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The carotenogenesis pathway via the isoprenoid-beta-carotene interference approach in a new strain of Dunaliella salina isolated from Baja California Mexico.

Paniagua-Michel J, Capa-Robles W, Olmos-Soto J, Gutierrez-Millan LE - Mar Drugs (2009)

Bottom Line: When Carotenogenic and non-carotenogenic cells of D. salina BC02 were grown under photoautotrophic growth conditions in the presence of 200 microM fosmidomycin, carotenogenesis and the synthesis of beta-carotene were interrupted after two days in cultured D. salina cells.This result is an indirect consequence of the inhibition of the synthesis of isoprenoids and activity of the recombinant DXR enzyme thereby preventing the conversion of 1-deoxy-D-xylulose 5-phosphate (DXP) to 2-C-methyl-D-erythritol (MEP) and consequently interrupts the early steps of carotenogenesis in D. salina.The effect at the level of proteins and RNA was not evident.

View Article: PubMed Central - PubMed

Affiliation: Department of Marine Biotechnology, Centro de Investigación Científica y de Educación Superior de Ensenada, Ensenada 22860, México. jpaniagu@cicese.mx

ABSTRACT
D. salina is one of the recognized natural sources to produce beta-carotene, and an useful model for studying the role of inhibitors and enhancers of carotenogenesis. However there is little information in D. salina regarding whether the isoprenoid substrate can be influenced by stress factors (carotenogenic) or selective inhibitors which in turn may further contribute to elucidate the early steps of carotenogenesis and biosynthesis of beta-carotene. In this study, Dunaliella salina (BC02) isolated from La Salina BC Mexico, was subjected to the method of isoprenoids-beta-carotene interference in order to promote the interruption or accumulation of the programmed biosynthesis of carotenoids. When Carotenogenic and non-carotenogenic cells of D. salina BC02 were grown under photoautotrophic growth conditions in the presence of 200 microM fosmidomycin, carotenogenesis and the synthesis of beta-carotene were interrupted after two days in cultured D. salina cells. This result is an indirect consequence of the inhibition of the synthesis of isoprenoids and activity of the recombinant DXR enzyme thereby preventing the conversion of 1-deoxy-D-xylulose 5-phosphate (DXP) to 2-C-methyl-D-erythritol (MEP) and consequently interrupts the early steps of carotenogenesis in D. salina. The effect at the level of proteins and RNA was not evident. Mevinolin treated D. salina cells exhibited carotenogenesis and beta-carotene levels very similar to those of control cell cultures indicating that mevinolin not pursued any indirect action in the biosynthesis of isoprenoids and had no effect at the level of the HMG-CoA reductase, the key enzyme of the Ac/MVA pathway.

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Protein (dark bar) and RNA content (gray bar)  in D. salina  during carotenogenesis and exposed to inhibitors: 1, Control (C); 2, C+ 1.0 μM mevinolin; 3-6=, C+ 50, 100, 150 and  200  μM fosmidomycin respectively.
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f6-marinedrugs-07-00045: Protein (dark bar) and RNA content (gray bar) in D. salina during carotenogenesis and exposed to inhibitors: 1, Control (C); 2, C+ 1.0 μM mevinolin; 3-6=, C+ 50, 100, 150 and 200 μM fosmidomycin respectively.

Mentions: The action of fomidomycin slightly decreased the content of protein in D. salina, under non-carotenogenic conditions (Figure 6). At 1.0 μM mevinolin, there was no decrease in the content of protein. A similar trend was observed in RNA content during carotenogenesis. In principle, cellular RNA content was constant during carotenogenic conditions when D. salina was exposed to the assayed concentrations in mevinolin and fosmidomycin. Results in other Chlorophyte [23] have shown that total carotenoids were related to total proteins, suggesting that the enzyme (s) responsible for carotenoid synthesis must account for only a small part of total protein. This mechanism could indicate the importance of nitrogen to achieve adequate level of RNA and protein formation required for carotenoid biosynthesis during carotenogenesis.


The carotenogenesis pathway via the isoprenoid-beta-carotene interference approach in a new strain of Dunaliella salina isolated from Baja California Mexico.

Paniagua-Michel J, Capa-Robles W, Olmos-Soto J, Gutierrez-Millan LE - Mar Drugs (2009)

Protein (dark bar) and RNA content (gray bar)  in D. salina  during carotenogenesis and exposed to inhibitors: 1, Control (C); 2, C+ 1.0 μM mevinolin; 3-6=, C+ 50, 100, 150 and  200  μM fosmidomycin respectively.
© Copyright Policy - open-access
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC2666888&req=5

f6-marinedrugs-07-00045: Protein (dark bar) and RNA content (gray bar) in D. salina during carotenogenesis and exposed to inhibitors: 1, Control (C); 2, C+ 1.0 μM mevinolin; 3-6=, C+ 50, 100, 150 and 200 μM fosmidomycin respectively.
Mentions: The action of fomidomycin slightly decreased the content of protein in D. salina, under non-carotenogenic conditions (Figure 6). At 1.0 μM mevinolin, there was no decrease in the content of protein. A similar trend was observed in RNA content during carotenogenesis. In principle, cellular RNA content was constant during carotenogenic conditions when D. salina was exposed to the assayed concentrations in mevinolin and fosmidomycin. Results in other Chlorophyte [23] have shown that total carotenoids were related to total proteins, suggesting that the enzyme (s) responsible for carotenoid synthesis must account for only a small part of total protein. This mechanism could indicate the importance of nitrogen to achieve adequate level of RNA and protein formation required for carotenoid biosynthesis during carotenogenesis.

Bottom Line: When Carotenogenic and non-carotenogenic cells of D. salina BC02 were grown under photoautotrophic growth conditions in the presence of 200 microM fosmidomycin, carotenogenesis and the synthesis of beta-carotene were interrupted after two days in cultured D. salina cells.This result is an indirect consequence of the inhibition of the synthesis of isoprenoids and activity of the recombinant DXR enzyme thereby preventing the conversion of 1-deoxy-D-xylulose 5-phosphate (DXP) to 2-C-methyl-D-erythritol (MEP) and consequently interrupts the early steps of carotenogenesis in D. salina.The effect at the level of proteins and RNA was not evident.

View Article: PubMed Central - PubMed

Affiliation: Department of Marine Biotechnology, Centro de Investigación Científica y de Educación Superior de Ensenada, Ensenada 22860, México. jpaniagu@cicese.mx

ABSTRACT
D. salina is one of the recognized natural sources to produce beta-carotene, and an useful model for studying the role of inhibitors and enhancers of carotenogenesis. However there is little information in D. salina regarding whether the isoprenoid substrate can be influenced by stress factors (carotenogenic) or selective inhibitors which in turn may further contribute to elucidate the early steps of carotenogenesis and biosynthesis of beta-carotene. In this study, Dunaliella salina (BC02) isolated from La Salina BC Mexico, was subjected to the method of isoprenoids-beta-carotene interference in order to promote the interruption or accumulation of the programmed biosynthesis of carotenoids. When Carotenogenic and non-carotenogenic cells of D. salina BC02 were grown under photoautotrophic growth conditions in the presence of 200 microM fosmidomycin, carotenogenesis and the synthesis of beta-carotene were interrupted after two days in cultured D. salina cells. This result is an indirect consequence of the inhibition of the synthesis of isoprenoids and activity of the recombinant DXR enzyme thereby preventing the conversion of 1-deoxy-D-xylulose 5-phosphate (DXP) to 2-C-methyl-D-erythritol (MEP) and consequently interrupts the early steps of carotenogenesis in D. salina. The effect at the level of proteins and RNA was not evident. Mevinolin treated D. salina cells exhibited carotenogenesis and beta-carotene levels very similar to those of control cell cultures indicating that mevinolin not pursued any indirect action in the biosynthesis of isoprenoids and had no effect at the level of the HMG-CoA reductase, the key enzyme of the Ac/MVA pathway.

Show MeSH