Isolation of a FAD-GPDH gene encoding a mitochondrial FAD-dependent glycerol-3-phosphate dehydrogenase from Dunaliella salina

The mitochondrial FAD-dependent glycerol-3-phosphate dehydrogenase (FAD-GPDH), recently reported in plants, has been detailed in yeast and animal systems. It oxidizes glycerol-3- phosphate (G-3-P)to dihydroxyacetone phosphate (DHAP)on the outer surface of mitochondrial inner membrane. A cDNA encoding the Dunaliella salina mitochondrial glycerol-3-phosphate dehydrogenase (DsFAD-GPDH)has been cloned and sequenced. The full length cDNA is 2791 bp, with an open reading frame (ORF)encoding 650 predicted amino acids, which show strong homology to reported FAD-GPDHs and have an apparent mitochondrial targeting sequence in the N-terminal. The sequence has been submitted to the GenBank database under Accession No. DQ916107. Results of Real-Time Quantitative PCR and enzymatic assays show that expression of DsFAD-GPDH is enhanced at first by salt treatment, and repressed by oxygen deficiency and cold stress.