Comparison of in vitro and in vivo splice site selection in kappa-immunoglobulin precursor mRNA.
The processing of a number of kappa-immunoglobulin primary mRNA (pre-mRNA) constructs has been examined both in vitro and in vivo. When a kappa-immunoglobulin pre-mRNA containing multiple J segment splice sites is processed in vitro, the splice sites are used with equal frequency. The presence of signal exon, S-V intron, or variable (V) region has no effect on splice site selection in vitro. Nuclear extracts prepared from a lymphoid cell line do not restore correct splice site selection. Splice site selection in vitro can be altered by changing the position or sequence of J splice donor sites. These results differ from the processing of similar pre-mRNAs expressed in vivo by transient transfection. The 5'-most J splice donor site was exclusively selected in vivo, even in nonlymphoid cells, and even in transcripts where in vitro splicing favored a 3' J splice site. The in vitro results are consistent with a model proposing that splice site selection is influenced by splice site strength and proximity; however, our in vivo results demonstrate a number of discrepancies with such a model and suggest that splice site selection may be coupled to transcription or a higher-order nuclear structure.
D000818:Animals; D002467:Cell Nucleus / Q000378:metabolism; D004587:Electrophoresis, Agar Gel; D005091:Exons; D005803:Genes, Immunoglobulin; D005822:Genetic Vectors; D006367:HeLa Cells / Q000648:ultrastructure; D007145:Immunoglobulin kappa-Chains / Q000235:genetics*; D007438:Introns; D008214:Lymphocytes / Q000648:ultrastructure; D051379:Mice; D012322:RNA Precursors / Q000378:metabolism*; D012326:RNA Splicing
D007145:Immunoglobulin kappa-Chains; D012322:RNA Precursors