The snRNP-associated U1A levels change following IL-6 stimulation of human B-cells.

The U1A protein can be found both in a small-ribonucleoprotein particle (snRNP) that contains U1 RNA, or in a distinctive fraction, free of the snRNP, the SF-A complex. Both components have been shown to influence post- or co-transcriptional RNA processing reactions in HeLa cells. Since U1A may influence the processing of the immunoglobulin heavy chain pre-mRNA in B-cells, we wanted to see if the levels of U1A in either of its two forms changed following IL-6 stimulation to IgM secretion.