Molecular cloning of murine folylpoly-y-glutamate synthetase

摘要

Folylpoly-γ-glutamate synthetase (FPGS) is essential for mammalian cell survival and is a major determinant of eytoto.xieity and selectivity for folate antimctabolites. Here we describe the cloning of a cDNA encoding murine FPGS isolated from LI2H) leukemia cells. The amino acid sequence of murine FPGS is H2% identical to human FPCiS [1] with identical discrete regions of up to 41 residues. Murine FPGS contains two AUG initiation codons, shown to be responsible for miiochondrial and cytosolic forms of the enzyme in human cells [2]. Previous studies indicated species, tissue, and tumor specific differences in mammalian FPGS. The availability of murine FPGS expands the knowledge and understanding of the spectrum of these variations.