Isolation and characterization of a cDNA from Catharanthus roseus which is highly homologous with phosphate transporter

The PIT1 gene which is highly homologous with phosphate transporter was isolated from Catharanthus roseus and analyzed. The cBNA PIT1 contained an open reading frame of 542 amino acids and its sequence showed a 31, 30, and 34% identity with the phosphate transporter of Saccharomyces cerevisiae (PBO84), Neurospora crassa (PHO-5), and Glomus versiforme (GvPT), respectively. Furthermore, the cDNA PIT1 encoded a highly hydrophobic protein with 12 putative membrane-spanning regions and contained a conserved amino acid sequence reported in the human glucose transporter super-family* S. cerevisiae strain DpU (pho84 knockout strain) was unable to grow on low phosphate (55 μM) medium (LP medium). Expression of the PIT1 cDNA enabled DpU to grow on LP medium. Northern hybridization analysis revealed that the PIT1 gene was expressed in roots, stems, and young whole plant of C. roseus, but not in leaves.