Cloning of cDNA for asparagine synthetase from rat Sertoli cell

We have cloned and sequenced cDNA of asparagine synthetase (AS) from rat Sertoli cells. The nucleotide sequence was derived by analysis of cloned cDNA of reverse transcription-polymerase chain reaction (RT-PCR) product that spanned overall the cDNA coding region. The sequence contains three nucleotide differences when compared with that of rat Fao hepatoma cells (Hutson, R.G., and Kilberg, M.S. (1994) Biochem. J. 304, 745-750). Accordingly, amino acid residues Ser at position 330 and His at 491 of Sertoli cells were replaced by Pro and Tyr, respectively, in the sequence of the hepatoma cells. Mutational nucleotide changes may occur during carcinogenesis. The testis contained the most abundant AS mRNA among the tissues studied and others revealed by far a little amount of message. Expressions of AS mRNA in the liver and brain were high in fetal period and reduced rapidly after birth, showing importance of AS in cell proliferation.