Energy-linked anion transport. Cloning, sequencing, and characterization of a full length cDNA encoding the rat liver mitochondrial proton/phosphate symporter

• Published in: The Journal of biological chemistry Vol. 264; no. 26; pp. 15628 - 15633
• Main Authors: Ferreira, G C, Pratt, R D, Pedersen, P L
• Format: Journal Article
• Language: English
• Published: United States American Society for Biochemistry and Molecular Biology 15-09-1989
• Subjects: Amino Acid Sequence; Animals; Base Sequence; Carrier Proteins - genetics; Cloning, Molecular; DNA, Mitochondrial - genetics; Genes; mitochondria; Mitochondria, Liver - metabolism; Models, Molecular; Molecular Sequence Data; Phosphate-Binding Proteins; Phosphates - metabolism; Protein Conformation; Rats; Restriction Mapping; Saccharomyces cerevisiae - genetics
• ISSN: 0021-9258; 1083-351X

A full length cDNA clone encoding the precursor of the rat liver mitochondrial phosphate transporter (H+/Pi symporter) has
been isolated from a cDNA library using a bovine heart partial length phosphate transporter clone as a hybridization probe.
The entire clone is 1263 base pairs in length with 5'- and 3'-untranslated regions of 16 and 168 base pairs, respectively.
The open reading frame encodes for the mature protein (312 amino acids) preceded by a presequence of 44 amino acids enriched
in basic residues. The polypeptide sequence predicted from the DNA sequence was confirmed by analyzing the first 17 amino-terminal
amino acids of the pure phosphate transporter protein. The rat liver phosphate transporter differs from the bovine heart transporter
in 32 amino acids (i.e. approximately 10%). It contains a region from amino acid 139 to 159 which is 37% identical with the
beta-subunit of the liver mitochondrial ATP synthase. Amino acid sequence comparisons of the Pi transporter with Pi binding
proteins, other H+-linked symporters, and the human glucose transporter did not reveal significant sequence homology. Analysis
of genomic DNA from both rat and S. cerevisiae by Southern blots using the rat liver mitochondrial Pi carrier cDNA as a probe
revealed remarkably similar restriction patterns, a finding consistent with the presence in lower and higher eukaryotes of
homologous Pi carrier proteins. This is the first report of the isolation, sequencing, and characterization of a full length
cDNA coding for a protein involved in energy-coupled Pi transport.