Origins of the Multiple Cathepsin E Transcripts Observed in Human Gastric Mucosa and Gastric Adenocarcinoma
We previously reported the cloning and sequence analysis of human gastric cathepsin E (CTSE) cDNA clones. The cDNA clones were isolated from a gastric adenocarcinoma recombinant library using a set of complementary nondegenerate 18mer oligonucleotide probes specific for a 6 residue sequence surrounding the first active site region of all previously characterized human aspartic proteinases.1 Northern analysis of poly (A+) RNA isolated from CTSE producing gastric adenocarcinoma cell line revealed three transcripts (3.6, 2.6 and 2.1 kb). The multiple CTSE transcripts are a unique finding among aspartic proteinases and may result from several potential causes including; multiple genes, rearranged genes, alternative initiation of transcription, alternative splicing or alternative polyadenylation. In the present study, we examined additional CTSE cDNA clones in an attempt to determine the origin of multiple transcripts observed in gastric adenocarcinoma. We present here evidence that two major CTSE transcripts (2.6 and 2.1 kb) result from alternative polyadenylation of the primary CTSE transcript.
KeywordsGastric Adenocarcinoma Northern Analysis Aspartic Proteinase Isoamyl Alcohol Alternative Polyadenylation
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