Schaub Michael C, Lopez Suzette R, Caputi Massimo
Department of Biomedical Science, Florida Atlantic University, Boca Raton, Florida 33431, USA.
J Biol Chem. 2007 May 4;282(18):13617-26. doi: 10.1074/jbc.M700774200. Epub 2007 Mar 2.
In this study we analyzed members of the heterogeneous nuclear ribonucleoprotein (hnRNP) H protein family to determine their RNA binding specificities and roles in splicing regulation. Our data indicate that hnRNPs H, H', F, 2H9, and GRSF-1 bind the consensus motif DGGGD (where D is U, G, or A) and aggregate in a multimeric complex. We analyzed the role of these proteins in the splicing of a substrate derived from the HIV-1 tat gene and have shown that hnRNP H family members are required for efficient splicing of this substrate. The hnRNP H protein family members activated splicing of the viral substrate by promoting the formation of ATP-dependent spliceosomal complexes. Mutational analysis of six consensus motifs present within the intron of the substrate indicated that only one of these motifs acts as an intronic splicing enhancer.
在本研究中，我们分析了不均一核核糖核蛋白（hnRNP）H蛋白家族的成员，以确定它们的RNA结合特异性以及在剪接调控中的作用。我们的数据表明，hnRNP H、H'、F、2H9和GRSF-1结合共有基序DGGGD（其中D为U、G或A）并聚集形成多聚体复合物。我们分析了这些蛋白质在源自HIV-1 tat基因的底物剪接中的作用，并表明hnRNP H家族成员是该底物有效剪接所必需的。hnRNP H蛋白家族成员通过促进ATP依赖性剪接体复合物的形成来激活病毒底物的剪接。对底物内含子中存在的六个共有基序的突变分析表明，这些基序中只有一个作为内含子剪接增强子起作用。
