| Abstract: | We have identified in a human cDNA library a clone (hp2F1) whose cognate RNA is growth-regulated. The insert has been sequenced and the nucleotide sequence shows a strong homology to the nucleotide sequences of the ADP/ATP carrier cDNA and gene, respectively, isolated from Neurospora crassa and Saccharomyces cerevisiae. The putative amino acid sequence of hp2F1 shows an 87% homology to the amino acid sequence of the ADP/ATP carrier from beef heart mitochondria. We conclude that the insert of hp2F1 contains the full coding sequence of a human ADP/ATP carrier. The steady-state RNA levels of the ADP/ATP carrier are growth-regulated. They increase when quiescent cells are stimulated by serum, platelet-derived growth factor, or epidermal growth factor, but not by platelet-poor plasma or insulin. RNA levels of the ADP/ATP carrier decrease instead when growing HL-60 cells are induced to differentiate by either phorbol esters or retinoic acid. |
