Alternative splicing of human papillomavirus type-16 e6-messenger RNA in mouse and monkey cell-lines

Previous studies have indicated that the splice patterns of E6-transcripts of human papillomavirus type-16 (HPV-16) are uniform. The splice ratios of E6-transcripts, however, seem to be variable in several HPV-positive cell lines, suggesting that cellular factors may affect the alternative splicing of E6-transcripts. To test this hypothesis, the splice ratios of E6-transcripts in various HPV-16 E6-expressing cell lines derived from CV-1 and 10T1/2 cells were quantitatively evaluated by S1 nuclease protection assays. The splice ratios varied among cell lines derived from the same parental lines, indicating that factors specific to cell-type do not play a major role in alternative splicing. The splice ratios appeared to be low in cell lines which prominently expressed longer than expected E6-transcripts indicating that the structure of the E6-transcript affects its splicing. Analysis of the expression patterns of COS-1 cells which transiently expressed various E6-transcript constructs suggested that structure was a factor in determining alternative splicing.