8qxd

From Proteopedia

(Difference between revisions)

Current revision

Cryo-EM structure of the cross-exon pre-B complex

Structural highlights

8qxd is a 10 chain structure with sequence from Homo sapiens. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance.
Method:	Electron Microscopy, Resolution 9.6Å
Resources:	FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT

Disease

PRP8_HUMAN Defects in PRPF8 are the cause of retinitis pigmentosa type 13 (RP13) [MIM:600059. RP leads to degeneration of retinal photoreceptor cells. Patients typically have night vision blindness and loss of midperipheral visual field. As their condition progresses, they lose their far peripheral visual field and eventually central vision as well. RP13 inheritance is autosomal dominant.^[1] ^[2] [:]^[3] ^[4]

Function

PRP8_HUMAN Central component of the spliceosome, which may play a role in aligning the pre-mRNA 5'- and 3'-exons for ligation. Interacts with U5 snRNA, and with pre-mRNA 5'-splice sites in B spliceosomes and 3'-splice sites in C spliceosomes.

Publication Abstract from PubMed

Early spliceosome assembly can occur through an intron-defined pathway, whereby U1 and U2 small nuclear ribonucleoprotein particles (snRNPs) assemble across the intron(1). Alternatively, it can occur through an exon-defined pathway(2-5), whereby U2 binds the branch site located upstream of the defined exon and U1 snRNP interacts with the 5' splice site located directly downstream of it. The U4/U6.U5 tri-snRNP subsequently binds to produce a cross-intron (CI) or cross-exon (CE) pre-B complex, which is then converted to the spliceosomal B complex(6,7). Exon definition promotes the splicing of upstream introns(2,8,9) and plays a key part in alternative splicing regulation(10-16). However, the three-dimensional structure of exon-defined spliceosomal complexes and the molecular mechanism of the conversion from a CE-organized to a CI-organized spliceosome, a pre-requisite for splicing catalysis, remain poorly understood. Here cryo-electron microscopy analyses of human CE pre-B complex and B-like complexes reveal extensive structural similarities with their CI counterparts. The results indicate that the CE and CI spliceosome assembly pathways converge already at the pre-B stage. Add-back experiments using purified CE pre-B complexes, coupled with cryo-electron microscopy, elucidate the order of the extensive remodelling events that accompany the formation of B complexes and B-like complexes. The molecular triggers and roles of B-specific proteins in these rearrangements are also identified. We show that CE pre-B complexes can productively bind in trans to a U1 snRNP-bound 5' splice site. Together, our studies provide new mechanistic insights into the CE to CI switch during spliceosome assembly and its effect on pre-mRNA splice site pairing at this stage.

Structural insights into the cross-exon to cross-intron spliceosome switch.,Zhang Z, Kumar V, Dybkov O, Will CL, Zhong J, Ludwig SEJ, Urlaub H, Kastner B, Stark H, Luhrmann R Nature. 2024 May 22. doi: 10.1038/s41586-024-07458-1. PMID:38778104^[5]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

References

↑ Pena V, Liu S, Bujnicki JM, Luhrmann R, Wahl MC. Structure of a multipartite protein-protein interaction domain in splicing factor prp8 and its link to retinitis pigmentosa. Mol Cell. 2007 Feb 23;25(4):615-24. PMID:17317632 doi:10.1016/j.molcel.2007.01.023
↑ McKie AB, McHale JC, Keen TJ, Tarttelin EE, Goliath R, van Lith-Verhoeven JJ, Greenberg J, Ramesar RS, Hoyng CB, Cremers FP, Mackey DA, Bhattacharya SS, Bird AC, Markham AF, Inglehearn CF. Mutations in the pre-mRNA splicing factor gene PRPC8 in autosomal dominant retinitis pigmentosa (RP13). Hum Mol Genet. 2001 Jul 15;10(15):1555-62. PMID:11468273
↑ van Lith-Verhoeven JJ, van der Velde-Visser SD, Sohocki MM, Deutman AF, Brink HM, Cremers FP, Hoyng CB. Clinical characterization, linkage analysis, and PRPC8 mutation analysis of a family with autosomal dominant retinitis pigmentosa type 13 (RP13). Ophthalmic Genet. 2002 Mar;23(1):1-12. PMID:11910553
↑ Martinez-Gimeno M, Gamundi MJ, Hernan I, Maseras M, Milla E, Ayuso C, Garcia-Sandoval B, Beneyto M, Vilela C, Baiget M, Antinolo G, Carballo M. Mutations in the pre-mRNA splicing-factor genes PRPF3, PRPF8, and PRPF31 in Spanish families with autosomal dominant retinitis pigmentosa. Invest Ophthalmol Vis Sci. 2003 May;44(5):2171-7. PMID:12714658
↑ Zhang Z, Kumar V, Dybkov O, Will CL, Zhong J, Ludwig SEJ, Urlaub H, Kastner B, Stark H, Lührmann R. Structural insights into the cross-exon to cross-intron spliceosome switch. Nature. 2024 May 22. PMID:38778104 doi:10.1038/s41586-024-07458-1

1 Structural highlights
2 Disease
3 Function
4 Publication Abstract from PubMed
5 References

Proteopedia Page Contributors and Editors (what is this?)

OCA

Retrieved from "http://52.214.119.220/wiki/index.php/8qxd"

@@ Line 3: / Line 3: @@
 <StructureSection load='8qxd' size='340' side='right'caption='[[8qxd]], [[Resolution|resolution]] 9.60&Aring;' scene=''>
 == Structural highlights ==
-<table><tr><td colspan='2'>[[8qxd]] is a 14 chain structure with sequence from [https://en.wikipedia.org/wiki/Homo_sapiens Homo sapiens]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=8QXD OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=8QXD FirstGlance]. <br>
+<table><tr><td colspan='2'>[[8qxd]] is a 10 chain structure with sequence from [https://en.wikipedia.org/wiki/Homo_sapiens Homo sapiens]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=8QXD OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=8QXD FirstGlance]. <br>
 </td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">Electron Microscopy, [[Resolution|Resolution]] 9.6&#8491;</td></tr>
 <tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[https://proteopedia.org/fgij/fg.htm?mol=8qxd FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=8qxd OCA], [https://pdbe.org/8qxd PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=8qxd RCSB], [https://www.ebi.ac.uk/pdbsum/8qxd PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=8qxd ProSAT]</span></td></tr>
@@ Line 11: / Line 11: @@
 == Function ==
 [https://www.uniprot.org/uniprot/PRP8_HUMAN PRP8_HUMAN] Central component of the spliceosome, which may play a role in aligning the pre-mRNA 5'- and 3'-exons for ligation. Interacts with U5 snRNA, and with pre-mRNA 5'-splice sites in B spliceosomes and 3'-splice sites in C spliceosomes.
+<div style="background-color:#fffaf0;">
+== Publication Abstract from PubMed ==
+Early spliceosome assembly can occur through an intron-defined pathway, whereby U1 and U2 small nuclear ribonucleoprotein particles (snRNPs) assemble across the intron(1). Alternatively, it can occur through an exon-defined pathway(2-5), whereby U2 binds the branch site located upstream of the defined exon and U1 snRNP interacts with the 5' splice site located directly downstream of it. The U4/U6.U5 tri-snRNP subsequently binds to produce a cross-intron (CI) or cross-exon (CE) pre-B complex, which is then converted to the spliceosomal B complex(6,7). Exon definition promotes the splicing of upstream introns(2,8,9) and plays a key part in alternative splicing regulation(10-16). However, the three-dimensional structure of exon-defined spliceosomal complexes and the molecular mechanism of the conversion from a CE-organized to a CI-organized spliceosome, a pre-requisite for splicing catalysis, remain poorly understood. Here cryo-electron microscopy analyses of human CE pre-B complex and B-like complexes reveal extensive structural similarities with their CI counterparts. The results indicate that the CE and CI spliceosome assembly pathways converge already at the pre-B stage. Add-back experiments using purified CE pre-B complexes, coupled with cryo-electron microscopy, elucidate the order of the extensive remodelling events that accompany the formation of B complexes and B-like complexes. The molecular triggers and roles of B-specific proteins in these rearrangements are also identified. We show that CE pre-B complexes can productively bind in trans to a U1 snRNP-bound 5' splice site. Together, our studies provide new mechanistic insights into the CE to CI switch during spliceosome assembly and its effect on pre-mRNA splice site pairing at this stage.
+Structural insights into the cross-exon to cross-intron spliceosome switch.,Zhang Z, Kumar V, Dybkov O, Will CL, Zhong J, Ludwig SEJ, Urlaub H, Kastner B, Stark H, Luhrmann R Nature. 2024 May 22. doi: 10.1038/s41586-024-07458-1. PMID:38778104<ref>PMID:38778104</ref>
+From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
+</div>
+<div class="pdbe-citations 8qxd" style="background-color:#fffaf0;"></div>
 == References ==
 <references/>

8qxd

From Proteopedia

Current revision

Cryo-EM structure of the cross-exon pre-B complex

Structural highlights

Disease

Function

Publication Abstract from PubMed

References

Contents

Proteopedia Page Contributors and Editors (what is this?)

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