The developmentally regulated shift from membrane to secreted mu mRNA production is accompanied by an increase in cleavage-polyadenylation efficiency but no measurable change in splicing efficiency.
To determine whether there are any developmental changes in the efficiencies of cleavage-polyadenylation or splicing reactions that could affect the usage of weak (suboptimal) processing signals and thus provide a basis for the regulated production of mu m versus mu s mRNA during B-lymphocyte maturation, we studied the expression of transfected mu genes in which the natural competition between cleavage-polyadenylation and splicing was replaced by alternative usage of tandem weak and strong poly(A) sites or by competition between suboptimal and optimal 5' splice junctions. Our results indicate that there is a 50 to 100% increase in cleavage-polyadenylation efficiency but no measurable change in splicing efficiency as maturation proceeds from the B-cell to plasma cell stage.
Peterson
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ML
Institute for Cancer Research, Fox Chase Cancer Center, Philadelphia, Pennsylvania 19111.
Gimmi
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ER
Perry
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RP
D017456:Adenovirus Early Proteins; D000818:Animals; D001667:Binding, Competitive; D002462:Cell Membrane / Q000378:metabolism*; D005796:Genes; D007148:Immunoglobulin mu-Chains / Q000235:genetics*; D051379:Mice; D009856:Oncogene Proteins, Viral / Q000235:genetics; D010954:Plasmacytoma; D011061:Poly A / Q000378:metabolism*; D012326:RNA Splicing; D012333:RNA, Messenger / Q000378:metabolism; D014162:Transfection; D014407:Tumor Cells, Cultured
D017456:Adenovirus Early Proteins; D007148:Immunoglobulin mu-Chains; D009856:Oncogene Proteins, Viral; D012333:RNA, Messenger; D011061:Poly A