Fig. 3a, b

ZC3H41 and Z41AP bind RNA in vivo. Cell lines expressing TAP-DRBD3, TAP-ZC3H41, TAP-Z41AP or TAP tag alone were irradiated (+) or not (−) with ultraviolet light. TAP-tagged proteins were immunoprecipitated using paramagnetic immunoglobulin G beads, end-labeled with [γ-³²P]ATP and polynucleotide kinase (PNK), and subjected to sodium dodecyl sulfate-polyacrylamide gel electrophoresis and PhosphorImager detection [³²P (left panels)]; TAP-tagged proteins were also visualized by immunoblot using Papanicolaou reagent [Immunoblot (right panels)]. a Trypanosomes expressing the TAP tag alone or TAP-DRBD3 were used as negative or positive controls, respectively; bands below TAP-DRBD3 probably represent degradation products (vertical line). b Immunoprecipitation and PNK labeling of cells expressing either TAP-ZC3H41 (Z) or TAP-Z41AP (AP). TAP-tagged species are indicated with asterisks. For other abbreviations, see Figs. 1 and 2