Artículos de revistas
In Silico Cloning and Characterization of the Glycerol-3-Phosphate Dehydrogenase (GPDH) Gene Family in the Green MicroalgaChlamydomonas reinhardtii
Autor
SANTY PERAZA ECHEVERRIA
Institución
Resumen
Glycerol-3-phosphate dehydrogenase (GPDH)
catalyzes the conversion of dihydroxyacetone phosphate
(DHAP) and NADH to glycerol-3-phosphate (G3P) and
NAD
?
. G3P is important as a precursor for glycerol and
glycerolipid synthesis in microalgae. A GPDH enzyme has
been previously purified from the green microalgaChlamydomonas reinhardtii, however, no genes coding for
GPDH have been characterized before. In this study, we
report the in silico characterization of three putativeGPDH
genes from C. reinhardtii: CrGPDH1, CrGPDH2, and
CrGPDH3. These sequences showed a significant similarity to characterized GPDHgenes from the microalgae
Dunaliella salinaandDunaliella viridis. The prediction of
the three-dimensional structure of the proteins showed the
characteristic fold topology of GPDH enzymes. Furthermore, the phylogenetic analysis showed that the three
CrGPDHs share the same clade with characterized GPDHs
fromDunaliellasuggesting a common evolutionary origin
and a similar catalytic function. In addition, the Ka
/Ks
ratios of these sequences suggested that they are under
purifying selection. Moreover, the expression analysis
showed a constitutive expression of CrGPDH1, while
CrGPDH2and CrGPDH3were induced in response to
osmotic stress, suggesting a possible role for these two
sequences in the synthesis of glycerol as a compatible
solute in osmoregulation, and perhaps also in lipid synthesis in C. reinhardtii. This study has provided a foundation for further biochemical and genetic studies of the
GPDHfamily in this model microalga, and also opportunities to assess the potential of these genes to enhance the
synthesis of TAGs for biodiesel production.