Human rasGTPase-activating protein (human counterpart of GAP1^m): Sequence of the cDNA, primary structure of the protein, production and chromosomal localization

When cDNA encoding rat rasGTPase-activating protein (rat GAP1^m) was used as a probe, two partial cDNA clones of a human counterpart of rat GAP1^m were isolated from a cDNA library derived from growth-arrested normal human ectocervical epithelial cells. One clone was found to be a cDNA of premature mRNA with two introns. A complete cDNA of human GAP1^m was constructed by a series of reverse transcription-polymerase chain reaction (RT-PCR) using total RNA from human epidermoid carcinoma A431 cells. Human GAP1^m shows 87.7% nucleotide identity to rat GAP1^m in open reading frame and encodes an 850-amino acid protein that shows 89.2% identity to rat GAP1^m. A 100-kDa protein was detected in A431 cells by Western blotting with anti-rat GAP1^m antibody. The human GAP1^m gene was mapped to chromosome 3q24-q26.