A novel aberrant splicing of G(s alpha) transcript in human leukemia cell lines

The alpha subunit of the stimulatory G protein, G(s alpha), is involved in the stimulation of adenylate cyclase pathway of signal transduction. The va rious G(s alpha) mRNAs are generated either by alternative splicing or by u sing alternative promoter. A novel aberrant splicing of G(s alpha) transcri pt in human leukemia cell lines is reported. The entire coding region of G( s alpha) gene obtained, referred to as G(s alpha Leu) was amplified by PCR with cDNA from Jurkat human leukemia cDNA library or the reverse-transcribe d first strand cDNA from human leukemia cell line HL-60 as a template. The result of DNA sequencing indicated that, compared with originally reported G(s alpha), G(soLeu) has two in-frame deletions, one in amino acid residues 23-249 and the other in amino acid residues 254-260, suggesting that G(s a lpha Leu) may play an important role in leukemia. The complete coding regio n of G(s alpha Leu) was inserted downstream of the thrombin site of pGEX-2T fusion protein expression vector and expressed in the form of GST/Gs(alpha Leu) at high level, which was then purified to be electrophoretically pure by one-step affinity chromatography. The expression of G(s alpha Leu) lays foundation for the study of its function.