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1q1t

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Revision as of 08:00, 24 February 2018

Mouse Importin alpha: non-phosphorylated SV40 CN peptide complex

Structural highlights

1q1t is a 3 chain structure with sequence from Lk3 transgenic mice. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance.
Related:	1ial, 1ejl, 1pjm, 1pjn, 1ejy
Gene:	KPNA2 OR RCH1 (LK3 transgenic mice)
Resources:	FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT

Function

[LT_SV40] Isoform large T antigen is a key early protein essential for both driving viral replication and inducing cellular transformation. Plays a role in viral genome replication by driving entry of quiescent cells into the cell cycle and by autoregulating the synthesis of viral early mRNA. Displays highly oncogenic activities by corrupting the host cellular checkpoint mechanisms that guard cell division and the transcription, replication, and repair of DNA. Participates in the modulation of cellular gene expression preceeding viral DNA replication. This step involves binding to host key cell cycle regulators retinoblastoma protein RB1/pRb and TP53. Induces the disassembly of host E2F1 transcription factors from RB1, thus promoting transcriptional activation of E2F1-regulated S-phase genes. Inhibits host TP53 binding to DNA, abrogating the ability of TP53 to stimulate gene expression. Plays the role of a TFIID-associated factor (TAF) in transcription initiation for all three RNA polymerases, by stabilizing the TBP-TFIIA complex on promoters. Initiates viral DNA replication and unwinding via interactions with the viral origin of replication. Binds two adjacent sites in the SV40 origin. The replication fork movement is facilitated by Large T antigen helicase activity. Activates the transcription of viral late mRNA, through host TBP and TFIIA stabilization. Interferes with histone deacetylation mediated by HDAC1, leading to activation of transcription. May inactivate the growth-suppressing properties of the E3 ubiquitin ligase CUL7.^[1] ^[2] ^[3] ^[4] ^[5] ^[6] ^[7] Isoform 17kT antigen targets host RBL2 for degradation and promotes cell proliferation. Transactivates host cyclin A promoter through its J domain.^[8] ^[9] ^[10] ^[11] ^[12] ^[13] ^[14]

Evolutionary Conservation

Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf.

Publication Abstract from PubMed

The nuclear import of simian-virus-40 large T-antigen (tumour antigen) is enhanced via phosphorylation by the protein kinase CK2 at Ser112 in the vicinity of the NLS (nuclear localization sequence). To determine the structural basis of the effect of the sequences flanking the basic cluster KKKRK, and the effect of phosphorylation on the recognition of the NLS by the nuclear import factor importin-alpha (Impalpha), we co-crystallized non-autoinhibited Impalpha with peptides corresponding to the phosphorylated and non-phosphorylated forms of the NLS, and determined the crystal structures of the complexes. The structures show that the amino acids N-terminally flanking the basic cluster make specific contacts with the receptor that are distinct from the interactions between bipartite NLSs and Impalpha. We confirm the important role of flanking sequences using binding assays. Unexpectedly, the regions of the peptides containing the phosphorylation site do not make specific contacts with the receptor. Binding assays confirm that phosphorylation does not increase the affinity of the T-antigen NLS to Impalpha. We conclude that the sequences flanking the basic clusters in NLSs play a crucial role in nuclear import by modulating the recognition of the NLS by Impalpha, whereas phosphorylation of the T-antigen enhances nuclear import by a mechanism that does not involve a direct interaction of the phosphorylated residue with Impalpha.

Role of flanking sequences and phosphorylation in the recognition of the simian-virus-40 large T-antigen nuclear localization sequences by importin-alpha.,Fontes MR, Teh T, Toth G, John A, Pavo I, Jans DA, Kobe B Biochem J. 2003 Oct 15;375(Pt 2):339-49. PMID:12852786^[15]

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

References

↑ Damania B, Alwine JC. TAF-like function of SV40 large T antigen. Genes Dev. 1996 Jun 1;10(11):1369-81. PMID:8647434
↑ Damania B, Lieberman P, Alwine JC. Simian virus 40 large T antigen stabilizes the TATA-binding protein-TFIIA complex on the TATA element. Mol Cell Biol. 1998 Jul;18(7):3926-35. PMID:9632777
↑ Zalvide J, Stubdal H, DeCaprio JA. The J domain of simian virus 40 large T antigen is required to functionally inactivate RB family proteins. Mol Cell Biol. 1998 Mar;18(3):1408-15. PMID:9488456
↑ Skoczylas C, Henglein B, Rundell K. PP2A-dependent transactivation of the cyclin A promoter by SV40 ST is mediated by a cell cycle-regulated E2F site. Virology. 2005 Feb 20;332(2):596-601. PMID:15680424 doi:10.1016/j.virol.2004.12.017
↑ Welcker M, Clurman BE. The SV40 large T antigen contains a decoy phosphodegron that mediates its interactions with Fbw7/hCdc4. J Biol Chem. 2005 Mar 4;280(9):7654-8. Epub 2004 Dec 20. PMID:15611062 doi:10.1074/jbc.M413377200
↑ Valls E, Blanco-Garcia N, Aquizu N, Piedra D, Estaras C, de la Cruz X, Martinez-Balbas MA. Involvement of chromatin and histone deacetylation in SV40 T antigen transcription regulation. Nucleic Acids Res. 2007;35(6):1958-68. Epub 2007 Mar 6. PMID:17341466 doi:gkl1113
↑ Hein J, Boichuk S, Wu J, Cheng Y, Freire R, Jat PS, Roberts TM, Gjoerup OV. Simian virus 40 large T antigen disrupts genome integrity and activates a DNA damage response via Bub1 binding. J Virol. 2009 Jan;83(1):117-27. doi: 10.1128/JVI.01515-08. Epub 2008 Oct 15. PMID:18922873 doi:10.1128/JVI.01515-08
↑ Damania B, Alwine JC. TAF-like function of SV40 large T antigen. Genes Dev. 1996 Jun 1;10(11):1369-81. PMID:8647434
↑ Damania B, Lieberman P, Alwine JC. Simian virus 40 large T antigen stabilizes the TATA-binding protein-TFIIA complex on the TATA element. Mol Cell Biol. 1998 Jul;18(7):3926-35. PMID:9632777
↑ Zalvide J, Stubdal H, DeCaprio JA. The J domain of simian virus 40 large T antigen is required to functionally inactivate RB family proteins. Mol Cell Biol. 1998 Mar;18(3):1408-15. PMID:9488456
↑ Skoczylas C, Henglein B, Rundell K. PP2A-dependent transactivation of the cyclin A promoter by SV40 ST is mediated by a cell cycle-regulated E2F site. Virology. 2005 Feb 20;332(2):596-601. PMID:15680424 doi:10.1016/j.virol.2004.12.017
↑ Welcker M, Clurman BE. The SV40 large T antigen contains a decoy phosphodegron that mediates its interactions with Fbw7/hCdc4. J Biol Chem. 2005 Mar 4;280(9):7654-8. Epub 2004 Dec 20. PMID:15611062 doi:10.1074/jbc.M413377200
↑ Valls E, Blanco-Garcia N, Aquizu N, Piedra D, Estaras C, de la Cruz X, Martinez-Balbas MA. Involvement of chromatin and histone deacetylation in SV40 T antigen transcription regulation. Nucleic Acids Res. 2007;35(6):1958-68. Epub 2007 Mar 6. PMID:17341466 doi:gkl1113
↑ Hein J, Boichuk S, Wu J, Cheng Y, Freire R, Jat PS, Roberts TM, Gjoerup OV. Simian virus 40 large T antigen disrupts genome integrity and activates a DNA damage response via Bub1 binding. J Virol. 2009 Jan;83(1):117-27. doi: 10.1128/JVI.01515-08. Epub 2008 Oct 15. PMID:18922873 doi:10.1128/JVI.01515-08
↑ Fontes MR, Teh T, Toth G, John A, Pavo I, Jans DA, Kobe B. Role of flanking sequences and phosphorylation in the recognition of the simian-virus-40 large T-antigen nuclear localization sequences by importin-alpha. Biochem J. 2003 Oct 15;375(Pt 2):339-49. PMID:12852786 doi:10.1042/BJ20030510

1 Structural highlights
2 Function
3 Evolutionary Conservation
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/1q1t"

@@ Line 1: / Line 1: @@
 ==Mouse Importin alpha: non-phosphorylated SV40 CN peptide complex==
 <StructureSection load='1q1t' size='340' side='right' caption='[[1q1t]], [[Resolution|resolution]] 2.50&Aring;' scene=''>
@@ Line 5: / Line 6: @@
 </td></tr><tr id='related'><td class="sblockLbl"><b>[[Related_structure|Related:]]</b></td><td class="sblockDat">[[1ial|1ial]], [[1ejl|1ejl]], [[1pjm|1pjm]], [[1pjn|1pjn]], [[1ejy|1ejy]]</td></tr>
 <tr id='gene'><td class="sblockLbl"><b>[[Gene|Gene:]]</b></td><td class="sblockDat">KPNA2 OR RCH1 ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=10090 LK3 transgenic mice])</td></tr>
-<tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=1q1t FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1q1t OCA], [http://pdbe.org/1q1t PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=1q1t RCSB], [http://www.ebi.ac.uk/pdbsum/1q1t PDBsum]</span></td></tr>
+<tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=1q1t FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1q1t OCA], [http://pdbe.org/1q1t PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=1q1t RCSB], [http://www.ebi.ac.uk/pdbsum/1q1t PDBsum], [http://prosat.h-its.org/prosat/prosatexe?pdbcode=1q1t ProSAT]</span></td></tr>
 </table>
 == Function ==
@@ Line 13: / Line 14: @@
 Check<jmol>
   <jmolCheckbox>
-    <scriptWhenChecked>select protein; define ~consurf_to_do selected; consurf_initial_scene = true; script "/wiki/ConSurf/q1/1q1t_consurf.spt"</scriptWhenChecked>
+    <scriptWhenChecked>; select protein; define ~consurf_to_do selected; consurf_initial_scene = true; script "/wiki/ConSurf/q1/1q1t_consurf.spt"</scriptWhenChecked>
     <scriptWhenUnchecked>script /wiki/extensions/Proteopedia/spt/initialview01.spt</scriptWhenUnchecked>
     <text>to colour the structure by Evolutionary Conservation</text>
@@ Line 28: / Line 29: @@
 </div>
 <div class="pdbe-citations 1q1t" style="background-color:#fffaf0;"></div>
-==See Also==
-*[[Importin|Importin]]
-*[[Large T Antigen|Large T Antigen]]
 == References ==
 <references/>

1q1t

From Proteopedia

Revision as of 08:00, 24 February 2018

Mouse Importin alpha: non-phosphorylated SV40 CN peptide complex

Structural highlights

Function

Evolutionary Conservation

Publication Abstract from PubMed

References

Contents

Proteopedia Page Contributors and Editors (what is this?)

Views

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