Biomaterial Database

Involvement of U1 small nuclear ribonucleoproteins (snRNP) in 5' splice site-U1 snRNP interaction. 1996

F Rossi, and T Forné, and E Antoine, and J Tazi, and C Brunel, and G Cathala

Institut de Génétique Moléculaire (IGM) UMR 5535 CNRS, Université de Montpellier II. CNRS-BP 5051, 1919 route de Mende, 34033 Montpellier cedex 1, France.

U1 small nuclear ribonucleoprotein (snRNP) is an important ribonucleoprotein involved early in the spliceosome formation to commit pre-mRNAs to the splicing pathway. We have determined the association and dissociation kinetics of the 5' splice site-U1 snRNP interaction using purified U1 snRNP and a short RNA oligonucleotide comprising the 5' splice site (5'-SS) consensus sequence of pre-mRNAs (5'-SS RNA oligo). The association is rapid, does not require ATP, and is almost irreversible. Surprisingly, oligonucleotide-directed cleavage of the U1 small nuclear RNA (snRNA) 5' end sequence with RNase H has no significant effect on the rate of association of the 5'-SS RNA oligo, but it does lead to rapid dissociation. This provides evidence that U1-specific snRNP proteins are critical for the 5' splice site recognition while base pairing ensures the stability of the interaction. The recognition of the 5' splice site by U1 snRNP does not result from the individual action of one or more proteins but rather from their organization around U1 snRNA. A consequence of this organization is that the U1-C protein makes direct contacts with the site, as it becomes cross-linked to the RNA oligo upon exposition of the reactions to shortwave UV light.

UI	MeSH Term	Description	Entries
D007700	Kinetics	The rate dynamics in chemical or physical systems.
D009841	Oligonucleotides	Polymers made up of a few (2-20) nucleotides. In molecular genetics, they refer to a short sequence synthesized to match a region where a mutation is known to occur, and then used as a probe (OLIGONUCLEOTIDE PROBES). (Dorland, 28th ed)	Oligonucleotide
D002474	Cell-Free System	A fractionated cell extract that maintains a biological function. A subcellular fraction isolated by ultracentrifugation or other separation techniques must first be isolated so that a process can be studied free from all of the complex side reactions that occur in a cell. The cell-free system is therefore widely used in cell biology. (From Alberts et al., Molecular Biology of the Cell, 2d ed, p166)	Cellfree System,Cell Free System,Cell-Free Systems,Cellfree Systems,System, Cell-Free,System, Cellfree,Systems, Cell-Free,Systems, Cellfree
D006367	HeLa Cells	The first continuously cultured human malignant CELL LINE, derived from the cervical carcinoma of Henrietta Lacks. These cells are used for, among other things, VIRUS CULTIVATION and PRECLINICAL DRUG EVALUATION assays.	Cell, HeLa,Cells, HeLa,HeLa Cell
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D006860	Hydrogen Bonding	A low-energy attractive force between hydrogen and another element. It plays a major role in determining the properties of water, proteins, and other compounds.	Hydrogen Bonds,Bond, Hydrogen,Hydrogen Bond
D012326	RNA Splicing	The ultimate exclusion of nonsense sequences or intervening sequences (introns) before the final RNA transcript is sent to the cytoplasm.	RNA, Messenger, Splicing,Splicing, RNA,RNA Splicings,Splicings, RNA
D012342	RNA, Small Nuclear	Short chains of RNA (100-300 nucleotides long) that are abundant in the nucleus and usually complexed with proteins in snRNPs (RIBONUCLEOPROTEINS, SMALL NUCLEAR). Many function in the processing of messenger RNA precursors. Others, the snoRNAs (RNA, SMALL NUCLEOLAR), are involved with the processing of ribosomal RNA precursors.	Low Molecular Weight Nuclear RNA,Small Nuclear RNA,snRNA,Chromatin-Associated RNA,Small Molecular Weight RNA,Chromatin Associated RNA,RNA, Chromatin-Associated
D013329	Structure-Activity Relationship	The relationship between the chemical structure of a compound and its biological or pharmacological activity. Compounds are often classed together because they have structural characteristics in common including shape, size, stereochemical arrangement, and distribution of functional groups.	Relationship, Structure-Activity,Relationships, Structure-Activity,Structure Activity Relationship,Structure-Activity Relationships
D016384	Consensus Sequence	A theoretical representative nucleotide or amino acid sequence in which each nucleotide or amino acid is the one which occurs most frequently at that site in the different sequences which occur in nature. The phrase also refers to an actual sequence which approximates the theoretical consensus. A known CONSERVED SEQUENCE set is represented by a consensus sequence. Commonly observed supersecondary protein structures (AMINO ACID MOTIFS) are often formed by conserved sequences.	Consensus Sequences,Sequence, Consensus,Sequences, Consensus