title: Conserved domains of human U4 snRNA required for snRNP and spliceosome assembly.
abstract: U4 snRNA is phylogenetically highly conserved and organized in several domains. To determine the function of each of the domains of human U4 snRNA in the multi-step process of snRNP and spliceosome assembly, we used reconstitution procedures in combination with snRNA mutagenesis. The highly conserved 5' terminal domain of U4 snRNA consists of the stem I and stem II regions that have been proposed to base pair with U6 snRNA, and the 5' stem-loop structure. We found that each of these structural elements is essential for spliceosome assembly. However, only the stem II region is required for U4-U6 interaction, and none of these elements for Sm protein binding. In contrast, the 3' terminal domain of U4 snRNA containing the Sm binding site is dispensable for both U4-U6 interaction and spliceosome assembly. Our results support an organization of the U4 snRNP into multiple functional domains, each of which acts at distinct stages of snRNP and spliceosome assembly.
authors: Max-Planck-Institut fuer Molekulare Genetik, Otto-Warburg-Laboratorium, Berlin, FRG.
authors: C
authors: C
authors: Wersig
authors: A
authors: A
authors: Bindereif
mesh_terms: D001483:Base Sequence; D002872:Chromosome Deletion; D006801:Humans; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D009690:Nucleic Acid Conformation; D015345:Oligonucleotide Probes; D010802:Phylogeny; D012326:RNA Splicing; D012342:RNA, Small Nuclear / Q000235:genetics* / Q000378:metabolism; D015183:Restriction Mapping; D012261:Ribonucleoproteins / Q000235:genetics*; D017411:Ribonucleoproteins, Small Nuclear
chemical_list: D015345:Oligonucleotide Probes; D012342:RNA, Small Nuclear; D012261:Ribonucleoproteins; D017411:Ribonucleoproteins, Small Nuclear