Diagrammatic representation of human KLK15 mRNA transcripts and confirmation of the exon B variant by RT-PCR. (A) Various isoforms (1-6) of KLK15 derived from the NCBI database are shown with the two new isoforms identified from the EST database containing novel exons, A and B, highlighted in red boxes. The unshaded boxes represent the noncoding exons, shaded black boxes for the isoforms represent the coding exons and the connecting lines the introns. Numbers inside boxes or above connecting lines represent exon or intron lengths in base pairs respectively. H, denotes histidine; S, denotes serine; and D, denotes aspartate [amino acids of the catalytic triad of the (putative) encoded proteins]. The arrowhead points to the common start codon and astericks (*) to the stop codon positions. (B) PCR was conducted on the cDNA from five different cell lines HOSE17.1 (1), PEO1 (2), OVCA432 (3), SKOV3 (4), LNCaP (5) and no cDNA (6) using the Forward primer in exon B and reverse primer in exon 2. Two products were obtained corresponding to with (144 bp) and without (70 bp) exon 1.