Iacobazzi V, Lauria G, Palmieri F
Department of Pharmaco-Biology, University of Bari and CNR Unit for the Study of Mitochondria and Bioenergetics, Italy.
DNA Seq. 1997;7(3-4):127-39. doi: 10.3109/10425179709034029.
The citrate (tricarboxylate) carrier transports citrate (or other tricarboxylates) across the inner membranes of mitochondria in an electroneutral exchange for malate (or other dicarboxylic acids). We have determined the sequence of the human citrate transporter gene from overlapping genomic clones generated by polymerase chain reactions by use of primers and probes based on the rat cDNA sequence and on emerging sequences. The gene is spread over 2.8 kb of human DNA and is divided into eight exons. All the introns are located at the level of the sequences coding for the extramembranous loops (and not for the transmembrane segments) of the mature protein. The open reading frame of the human gene encodes the mature protein consisting of 298 amino acids, preceded by a presequence of 13 amino acids to help to target it into mitochondria. 84 identities and 106 highly conservative substitutions are present in CTPs from man to yeast. In addition, we have determined the sequences of two human pseudogenes related to the citrate carrier gene encompassing the coding sequence of the gene between nucleotides 260 and 720.
柠檬酸（三羧酸）载体在线粒体内膜上以电中性方式将柠檬酸（或其他三羧酸）与苹果酸（或其他二羧酸）进行交换运输。我们利用基于大鼠cDNA序列和新出现序列设计的引物和探针，通过聚合酶链反应从重叠的基因组克隆中确定了人类柠檬酸转运蛋白基因的序列。该基因分布在2.8 kb的人类DNA上，分为8个外显子。所有内含子都位于成熟蛋白膜外环（而非跨膜片段）编码序列的水平。人类基因的开放阅读框编码由298个氨基酸组成的成熟蛋白，前面有13个氨基酸的前导序列，有助于将其靶向导入线粒体。从人到酵母的柠檬酸转运蛋白中存在84个相同位点和106个高度保守的替换。此外，我们还确定了两个与柠檬酸载体基因相关的人类假基因的序列，其包含该基因在核苷酸260至720之间的编码序列。
