Characterization and Differential Nuclear Localization of Nopp140 and a Novel Nopp140-Like Protein in Trypanosomes

Properties of Nopp140 proteins. (A) Alignment of all central domain repeats from TbNopp140 and TbNoLP. (B) Domain diagram of TbNopp140 and TbNoLP. (C) Alignment of SRP40 domain across a broad range of eukaryotes: Hs, Homo sapiens; Xl, Xenopus laevis; Dm, Drosophila melanogaster; Ce, Caenorhabditis elegans; Sc, Saccharomyces cerevisiae; Sp, Schizosaccharomyces pombe; Ps, Phytophthora sojae; Dd, Dictyostelium discoideum; At, Arabidopsis thaliana; Cm, Cyanidioschyzon merolae; Tg, Toxoplasma gondii; Ta, Theileria annulata; Cp, Cryptosporidium parvum; Tb, Trypanosoma brucei; Tc, Trypanosoma cruzi; Lm, Leishmania major; Gl, Giardia lamblia; Eh, Entamoeba histolytica; and Cr, Chlamydomonas reinhardtii. (D) Comparison between central domain size and mean charge per amino for Nopp140 and Nopp140-like proteins in the same set of organisms. (E) Immunoprecipitates from 10⁸ cells extracted in RIPA buffer with the addition of sodium dodecyl sulfate (SDS; as indicated), and detected with the NUMAG monoclonal antibody. A Pol I-specific monoclonal was used (lanes 2 to 4) along with an unrelated control (Cont.; lane 1).