scholarly journals Crystal structure of human U1 snRNP, a small nuclear ribonucleoprotein particle, reveals the mechanism of 5′ splice site recognition

eLife ◽  
2015 ◽  
Vol 4 ◽  
Author(s):  
Yasushi Kondo ◽  
Chris Oubridge ◽  
Anne-Marie M van Roon ◽  
Kiyoshi Nagai
Keyword(s):  
Protein Interactions ◽  
Splice Site ◽  
Electrostatic Interactions ◽  
Rna Binding ◽  
Early Stage ◽  
Splice Junction ◽  
Small Nuclear Ribonucleoprotein ◽  
U1 Snrna ◽  
U1 Snrnp ◽  
Rna Backbone

U1 snRNP binds to the 5′ exon-intron junction of pre-mRNA and thus plays a crucial role at an early stage of pre-mRNA splicing. We present two crystal structures of engineered U1 sub-structures, which together reveal at atomic resolution an almost complete network of protein–protein and RNA-protein interactions within U1 snRNP, and show how the 5′ splice site of pre-mRNA is recognised by U1 snRNP. The zinc-finger of U1-C interacts with the duplex between pre-mRNA and the 5′-end of U1 snRNA. The binding of the RNA duplex is stabilized by hydrogen bonds and electrostatic interactions between U1-C and the RNA backbone around the splice junction but U1-C makes no base-specific contacts with pre-mRNA. The structure, together with RNA binding assays, shows that the selection of 5′-splice site nucleotides by U1 snRNP is achieved predominantly through basepairing with U1 snRNA whilst U1-C fine-tunes relative affinities of mismatched 5′-splice sites.

scholarly journals p68 RNA Helicase Is an Essential Human Splicing Factor That Acts at the U1 snRNA-5′ Splice Site Duplex

2002 ◽  
Vol 22 (15) ◽  
pp. 5443-5450 ◽  
Author(s):  
Zhi-Ren Liu
Keyword(s):  
Splice Site ◽  
Early Stage ◽  
Rna Helicase ◽  
Mrna Splicing ◽  
Cross Linking ◽  
Spliceosome Assembly ◽  
U1 Snrna ◽  
U1 Snrnp ◽  
P68 Rna Helicase

ABSTRACT Modulation of the interaction between U1 snRNP and the 5′ splice site (5′ss) is a key event that governs 5′ss recognition and spliceosome assembly. Using the methylene blue-mediated cross-linking method (Z. R. Liu, A. M. Wilkie, M. J. Clemens, and C. W. Smith, RNA 2:611-621, 1996), a 65-kDa protein (p65) was shown to interact with the U1-5′ss duplex during spliceosome assembly (Z. R. Liu, B. Sargueil, and C. W. Smith, Mol. Cell. Biol. 18:6910-6920, 1998). In this report, p65 was identified as p68 RNA helicase and shown to be essential for in vitro pre-mRNA splicing. Depletion of endogenous p68 RNA helicase does not affect the loading of the U1 snRNP to the 5′ss during early stage of splicing. However, dissociation of the U1 from the 5′ss is largely inhibited. The data suggest that p68 RNA helicase functions in destabilizing the U1-5′ss interactions. Furthermore, depletion of p68 RNA helicase arrested spliceosome assembly at the prespliceosome stage, suggesting that p68 may play a role in the transition from prespliceosome to spliceosome.

scholarly journals The Pre-mRNA 5′ Cap Determines Whether U6 Small Nuclear RNA Succeeds U1 Small Nuclear Ribonucleoprotein Particle at 5′ Splice Sites

1998 ◽  
Vol 18 (12) ◽  
pp. 7510-7520 ◽  
Author(s):  
Laura O’Mullane ◽  
Ian C. Eperon
Keyword(s):  
Splice Site ◽  
Major Effect ◽  
Small Nuclear Rna ◽  
Splice Sites ◽  
U6 Snrna ◽  
Small Nuclear Ribonucleoprotein ◽  
U1 Snrna ◽  
U1 Snrnp ◽  
Nuclear Rna ◽  
Nuclear Ribonucleoprotein

ABSTRACT Efficient splicing of the 5′-most intron of pre-mRNA requires a 5′ m7G(5′)ppp(5′)N cap, which has been implicated in U1 snRNP binding to 5′ splice sites. We demonstrate that the cap alters the kinetic profile of U1 snRNP binding, but its major effect is on U6 snRNA binding. With two alternative wild-type splice sites in an adenovirus pre-mRNA, the cap selectively alters U1 snRNA binding at the site to which cap-independent U1 snRNP binding is stronger and that is used predominantly in splicing; with two consensus sites, the cap acts on both, even though one is substantially preferred for splicing. However, the most striking quantitative effect of the 5′ cap is neither on U1 snRNP binding nor on the assembly of large complexes but on the replacement of U1 snRNP by U6 snRNA at the 5′ splice site. Inhibition of splicing by a cap analogue is correlated with the loss of U6 interactions at the 5′ splice site and not with any loss of U1 snRNP binding.

scholarly journals Novel Splicing Factor RBM25 Modulates Bcl-x Pre-mRNA 5′ Splice Site Selection

2008 ◽  
Vol 28 (19) ◽  
pp. 5924-5936 ◽  
Author(s):  
AnYu Zhou ◽  
Alexander C. Ou ◽  
Aeri Cho ◽  
Edward J. Benz ◽  
Shu-Ching Huang
Keyword(s):  
Splice Site ◽  
Dependent Manner ◽  
Splice Site Selection ◽  
Exon 2 ◽  
Small Nuclear Ribonucleoprotein ◽  
U1 Snrnp ◽  
Nuclear Ribonucleoprotein ◽  
Dose Dependent ◽  
Selection Of

ABSTRACT RBM25 has been shown to associate with splicing cofactors SRm160/300 and assembled splicing complexes, but little is known about its splicing regulation. Here, we characterize the functional role of RBM25 in alternative pre-mRNA splicing. Increased RBM25 expression correlated with increased apoptosis and specifically affected the expression of Bcl-x isoforms. RBM25 stimulated proapoptotic Bcl-xS 5′ splice site (5′ ss) selection in a dose-dependent manner, whereas its depletion caused the accumulation of antiapoptotic Bcl-xL. Furthermore, RBM25 specifically bound to Bcl-x RNA through a CGGGCA sequence located within exon 2. Mutation in this element abolished the ability of RBM25 to enhance Bcl-xS 5′ ss selection, leading to decreased Bcl-xS isoform expression. Binding of RBM25 was shown to promote the recruitment of the U1 small nuclear ribonucleoprotein particle (snRNP) to the weak 5′ ss; however, it was not required when a strong consensus 5′ ss was present. In support of a role for RBM25 in modulating the selection of a 5′ ss, we demonstrated that RBM25 associated selectively with the human homolog of yeast U1 snRNP-associated factor hLuc7A. These data suggest a novel mode for Bcl-xS 5′ ss activation in which binding of RBM25 with exonic element CGGGCA may stabilize the pre-mRNA-U1 snRNP through interactions with hLuc7A.

scholarly journals Fourteen Residues of the U1 snRNP-Specific U1A Protein Are Required for Homodimerization, Cooperative RNA Binding, and Inhibition of Polyadenylation

2000 ◽  
Vol 20 (6) ◽  
pp. 2209-2217 ◽  
Author(s):  
Jacqueline M. T. Klein Gunnewiek ◽  
Reem I. Hussein ◽  
Yvonne van Aarssen ◽  
Daphne Palacios ◽  
Rob de Jong ◽  
...  
Keyword(s):  
Protein Interactions ◽  
Rna Binding ◽  
Structural Data ◽  
Protein Molecule ◽  
Cooperative Binding ◽  
Mobility Shift ◽  
Small Nuclear Ribonucleoprotein ◽  
U1a Protein

ABSTRACT It was previously shown that the human U1A protein, one of three U1 small nuclear ribonucleoprotein-specific proteins, autoregulates its own production by binding to and inhibiting the polyadenylation of its own pre-mRNA. The U1A autoregulatory complex requires two molecules of U1A protein to cooperatively bind a 50-nucleotide polyadenylation-inhibitory element (PIE) RNA located in the U1A 3′ untranslated region. Based on both biochemical and nuclear magnetic resonance structural data, it was predicted that protein-protein interactions between the N-terminal regions (amino acids [aa] 1 to 115) of the two U1A proteins would form the basis for cooperative binding to PIE RNA and for inhibition of polyadenylation. In this study, we not only experimentally confirmed these predictions but discovered some unexpected features of how the U1A autoregulatory complex functions. We found that the U1A protein homodimerizes in the yeast two-hybrid system even when its ability to bind RNA is incapacitated. U1A dimerization requires two separate regions, both located in the N-terminal 115 residues. Using both coselection and gel mobility shift assays, U1A dimerization was also observed in vitro and found to depend on the same two regions that were found in vivo. Mutation of the second homodimerization region (aa 103 to 115) also resulted in loss of inhibition of polyadenylation and loss of cooperative binding of two U1A protein molecules to PIE RNA. This same mutation had no effect on the binding of one U1A protein molecule to PIE RNA. A peptide containing two copies of aa 103 to 115 is a potent inhibitor of polyadenylation. Based on these data, a model of the U1A autoregulatory complex is presented.

scholarly journals Structure of a transcribing RNA polymerase II–U1 snRNP complex

Science ◽  
2021 ◽  
Vol 371 (6526) ◽  
pp. 305-309 ◽  
Author(s):  
Suyang Zhang ◽  
Shintaro Aibara ◽  
Seychelle M. Vos ◽  
Dmitry E. Agafonov ◽  
Reinhard Lührmann ◽  
...  
Keyword(s):  
Rna Polymerase ◽  
Rna Polymerase Ii ◽  
Splice Site ◽  
Messenger Rna ◽  
Loop Formation ◽  
Mrna Isoforms ◽  
Pol Ii ◽  
Small Nuclear Ribonucleoprotein ◽  
Starting Point ◽  
U1 Snrnp

To initiate cotranscriptional splicing, RNA polymerase II (Pol II) recruits the U1 small nuclear ribonucleoprotein particle (U1 snRNP) to nascent precursor messenger RNA (pre-mRNA). Here, we report the cryo–electron microscopy structure of a mammalian transcribing Pol II–U1 snRNP complex. The structure reveals that Pol II and U1 snRNP interact directly. This interaction positions the pre-mRNA 5′ splice site near the RNA exit site of Pol II. Extension of pre-mRNA retains the 5′ splice site, leading to the formation of a “growing intron loop.” Loop formation may facilitate scanning of nascent pre-mRNA for the 3′ splice site, functional pairing of distant intron ends, and prespliceosome assembly. Our results provide a starting point for a mechanistic analysis of cotranscriptional spliceosome assembly and the biogenesis of mRNA isoforms by alternative splicing.

scholarly journals U1 small nuclear ribonucleoprotein particle-specific proteins interact with the first and second stem-loops of U1 RNA, with the A protein binding directly to the RNA independently of the 70K and Sm proteins.

1989 ◽  
Vol 9 (8) ◽  
pp. 3360-3368 ◽  
Author(s):  
J R Patton ◽  
W Habets ◽  
W J van Venrooij ◽  
T Pederson
Keyword(s):  
Protein Interactions ◽  
Protein Protein Interactions ◽  
Ribonucleoprotein Particle ◽  
Small Nuclear Ribonucleoprotein ◽  
Core Proteins ◽  
U1 Snrnp ◽  
Specific Proteins ◽  
C Proteins ◽  
Nuclear Ribonucleoprotein ◽  
Small Nuclear Ribonucleoprotein Particle

The U1 small nuclear ribonucleoprotein particle (U1 snRNP), a cofactor in pre-mRNA splicing, contains three proteins, termed 70K, A, and C, that are not present in the other spliceosome-associated snRNPs. We studied the binding of the A and C proteins to U1 RNA, using a U1 snRNP reconstitution system and an antibody-induced nuclease protection technique. Antibodies that reacted with the A and C proteins induced nuclease protection of the first two stem-loops of U1 RNA in reconstituted U1 snRNP. Detailed analysis of the antibody-induced nuclease protection patterns indicated the existence of relatively long-range protein-protein interactions in the U1 snRNP, with the 5' end of U1 RNA and its associated specific proteins interacting with proteins bound to the Sm domain near the 3' end. UV cross-linking experiments in conjunction with an A-protein-specific antibody demonstrated that the A protein bound directly to the U1 RNA rather than assembling in the U1 snRNP exclusively via protein-protein interactions. This conclusion was supported by additional experiments revealing that the A protein could bind to U1 RNA in the absence of bound 70K and Sm core proteins.

scholarly journals Direct, sequence-specific binding of the human U1-70K ribonucleoprotein antigen protein to loop I of U1 small nuclear RNA.

1989 ◽  
Vol 9 (10) ◽  
pp. 4179-4186 ◽  
Author(s):  
C S Surowy ◽  
V L van Santen ◽  
S M Scheib-Wixted ◽  
R A Spritz
Keyword(s):  
Fusion Protein ◽  
Rna Binding ◽  
Specific Binding ◽  
Consensus Sequence ◽  
Small Nuclear Rna ◽  
Small Nuclear Ribonucleoprotein ◽  
U1 Snrna ◽  
Nuclear Rna ◽  
Mutation Analyses

We have studied the interaction of two of the U1 small nuclear ribonucleoprotein (snRNP)-specific proteins, U1-70K and U1-A, with U1 small nuclear RNA (snRNA). The U1-70K protein is a U1-specific RNA-binding protein. Deletion and mutation analyses of a beta-galactosidase/U1-70K partial fusion protein indicated that the central portion of the protein, including the RNP sequence domain, is both necessary and sufficient for specific U1 snRNA binding in vitro. The highly conserved eight-amino-acid RNP consensus sequence was found to be essential for binding. Deletion and mutation analyses of U1 snRNA showed that both the U1-70K fusion protein and the native HeLa U1-70K protein bound directly to loop I of U1 snRNA. Binding was sequence specific, requiring 8 of the 10 bases in the loop. The U1-A snRNP protein also interacted specifically with U1 snRNA, principally with stem-loop II.

scholarly journals Spatial Organization of Protein-RNA Interactions in the Branch Site-3′ Splice Site Region during pre-mRNA Splicing in Yeast

2003 ◽  
Vol 23 (12) ◽  
pp. 4174-4186 ◽  
Author(s):  
David S. McPheeters ◽  
Peggy Muhlenkamp
Keyword(s):  
Protein Interactions ◽  
Splice Site ◽  
Spatial Organization ◽  
Mrna Splicing ◽  
Second Step ◽  
Cross Linking ◽  
Branch Site ◽  
Small Nuclear Ribonucleoprotein ◽  
Exon Sequence ◽  
Exon Region

ABSTRACT A series of efficiently spliced pre-mRNA substrates containing single 4-thiouridine residues were used to monitor RNA-protein interactions involving the branch site-3′ splice site-3′ exon region during yeast pre-mRNA splicing through cross-linking analysis. Prior to the assembly of the prespliceosome, Mud2p and the branch point bridging protein cross-link to a portion of this region in an ATP-independent fashion. Assembly of the prespliceosome leads to extensive cross-linking of the U2-associated protein Hsh155p to this region. Following the first step of splicing and in a manner independent of Prp16p, the U5 small nuclear ribonucleoprotein particle-associated protein Prp8p also associates extensively with the branch site-3′ splice site-3′ exon region. The subsequent cross-linking of Prp16p to the lariat intermediate is restricted to the 3′ splice site and the adjacent 3′ exon sequence. Using modified substrates to either mutationally or chemically block the second step, we found that the association of Prp22p with the lariat intermediate represents an authentic transient intermediate and appears to be restricted to the last eight intron nucleotides. Completion of the second step leads to the cross-linking of an unidentified ∼80-kDa protein near the branch site sequence, suggesting a potential role for this protein in a later step in intron metabolism. Taken together, these data provide a detailed portrayal of the dynamic associations of proteins with the branch site-3′ splice site region during spliceosome assembly and catalysis.

scholarly journals A specific 31-nucleotide domain of U1 RNA directly interacts with the 70K small nuclear ribonucleoprotein component.

1989 ◽  
Vol 9 (11) ◽  
pp. 4872-4881 ◽  
Author(s):  
C C Query ◽  
R C Bentley ◽  
J D Keene
Keyword(s):  
Nucleotide Sequence ◽  
Splice Site ◽  
Rna Binding ◽  
Binding Domain ◽  
Specific Domain ◽  
Stem Loop ◽  
Small Nuclear Ribonucleoprotein ◽  
Associated Proteins ◽  
Nuclear Ribonucleoprotein

We have defined the nucleotide sequence of a protein-binding domain within U1 RNA that specifically recognizes and binds both to a U1 small nuclear ribonucleoprotein component (the 70K protein) and to the previously defined RNA-binding domain of the 70K protein. We have investigated direct interactions between purified U1 RNA and 70K protein by reconstitution in vitro. Thirty-one nucleotides of U1 RNA, corresponding to stem-loop I, were required for this interaction. Nucleotides at the 5' end of U1 RNA that are involved in base pairing with the 5' splice site of pre-mRNA were not required for binding. In contrast to other reports, these findings demonstrate that a specific domain of U1 RNA can bind directly to the 70K protein independently of any other snRNP-associated proteins.

Recognition of U1 and U2 small nuclear RNAs can be altered by a 5-amino-acid segment in the U2 small nuclear ribonucleoprotein particle (snRNP) B" protein and through interactions with U2 snRNP-A' protein

1991 ◽  
Vol 11 (4) ◽  
pp. 1829-1839
Author(s):  
R C Bentley ◽  
J D Keene
Keyword(s):  
Amino Acid ◽  
Rna Binding ◽  
Rna Recognition ◽  
Ribonucleoprotein Particle ◽  
Small Nuclear Ribonucleoprotein ◽  
U2 Snrnp ◽  
U1 Snrnp ◽  
Sequence Elements ◽  
Nuclear Ribonucleoprotein ◽  
Amino Acid Segment

We have investigated the sequence elements influencing RNA recognition in two closely related small nuclear ribonucleoprotein particle (snRNP) proteins, U1 snRNP-A and U2 snRNP-B". A 5-amino-acid segment in the RNA-binding domain of the U2 snRNP-B" protein was found to confer U2 RNA recognition when substituted into the corresponding position in the U1 snRNP-A protein. In addition, B", but not A, was found to require the U2 snRNP-A' protein as an accessory factor for high-affinity binding to U2 RNA. The pentamer segment in B" that conferred U2 RNA recognition was not sufficient to allow the A' enhancement of U2 RNA binding by B", thus implicating other sequences in this protein-protein interaction. Sequence elements involved in these interactions have been localized to variable loops of the RNA-binding domain as determined by nuclear magnetic resonance spectroscopy (D. Hoffman, C.C. Query, B. Golden, S.W. White, and J.D. Keene, Proc. Natl. Acad. Sci. USA, in press). These findings suggest a role for accessory proteins in the formation of RNP complexes and pinpoint amino acid sequences that affect the specificity of RNA recognition in two members of a large family of proteins involved in RNA processing.

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