This old version of Proteopedia is provided for student assignments while the new version is undergoing repairs. Content and edits done in this old version of Proteopedia after March 1, 2026 will eventually be lost when it is retired in about June of 2026.
Apply for new accounts at the new Proteopedia. Your logins will work in both the old and new versions.




Importin

From Proteopedia

(Difference between revisions)
Jump to: navigation, search
(New page: <StructureSection load='1ee5' size='340' side='right' caption='Structure of yeast importin α NLS-binding domain complex with nucleoplasmin peptide (PDB code 1ee5).' scene=''> == Fun...)
Current revision (10:14, 2 July 2024) (edit) (undo)
 
(17 intermediate revisions not shown.)
Line 1: Line 1:
-
 
+
<StructureSection load='1ee5' size='340' side='right' caption='Structure of yeast importin α NLS-binding domain (grey) complex with nucleoplasmin peptide (green) (PDB code [[1ee5]]).' scene=''>
-
<StructureSection load='1ee5' size='340' side='right' caption='Structure of yeast importin α NLS-binding domain complex with nucleoplasmin peptide (PDB code [[1ee5]]).' scene=''>
+
== Function ==
== Function ==
-
'''Importins''' (IPO) mediate the import of cellular proteins into the nucleus by binding to the nuclear localization signal (NLS). IMP has 2 subunits: α and β. IPO-α is an adaptor protein which binds the NLS. Proteins can contain one or two NLS motifs. IPO-α contains several armadillo repeats with two NLS-binding sites and an IPO-β binding site (IBB). IPO-β contains 19 HEAT repeats. Many nuclear proteins contain Phe-Gly sequences which can bind to HEAT repeats and thus be transported.
+
'''Importins''' (IPO) mediate the import of cellular proteins into the nucleus by binding to the '''N'''uclear '''L'''ocalization '''S'''ignal (NLS). IPO has 2 subunits: α and β. '''IPO-α''' is an adaptor protein which binds the NLS<ref>PMID:9759490</ref>. IPOs can contain one or two NLS motifs.
 +
*'''IPO-α''' contains several armadillo repeats with two NLS-binding sites and an IPO-β binding (IBB) site.
 +
*'''IPO-β''' contains 19 HEAT (solenoid domain) repeats. Many nuclear proteins contain Phe-Gly sequences which can bind to HEAT repeats and thus be transported.
 +
*'''IPO-4''' binds histones H3 and H4 and histone chaperone ASF1 for nuclear import<ref>PMID:36103578</ref>.
 +
*'''IPO-7''' drives the nuclear import of the regulator of mechanotransduction pathway YAP<ref>PMID:35246520</ref>.
 +
*'''IPO-9''' binds histones H2A and H2B for nuclear import<ref>PMID:30855230</ref>.
 +
*'''IPO-13''' has a role in oxidative stress-dependent nuclear export<ref>PMID:34625540</ref>.
 +
 
 +
See also [[Protein Transport Membrane Protein]].
== Disease ==
== Disease ==
 +
IPO-α isoform expression is altered in many kinds of cancer.
== Relevance ==
== Relevance ==
 +
Specific IPO-α isoforms are critical in nerve regenerative response after injury. Loss of IPO-α expression in aging myocardial cells could make recovery after heart disease in elderly patients more difficult<ref>PMID:25656054</ref>.
== Structural highlights ==
== Structural highlights ==
==3D structures of importin==
==3D structures of importin==
 +
[[Importin 3D structures]]
-
Updated on {{REVISIONDAY2}}-{{MONTHNAME|{{REVISIONMONTH}}}}-{{REVISIONYEAR}}
+
</StructureSection>
-
 
+
-
'''IPO-α'''
+
-
 
+
-
[[1ial]] – mIPO residues 44-496 – mouse<br />
+
-
[[1bk5]] – yIPO NLS-binding domain - yeast<br />
+
-
 
+
-
''IPO-α complex with NLS peptide''
+
-
 
+
-
[[1ejl]] – mIPO NLS-binding domain + SV40 large T antigen<br />
+
-
[[1ejy]] – mIPO NLS-binding domain + nucleoplasmin <br />
+
-
[[2ynr]] – mIPO NLS-binding domain + B54NLS <br />
+
-
[[1bk6]] – yIPO NLS-binding domain + SV40 large T antigen<br />
+
-
[[1ee4]] – yIPO NLS-binding domain (mutant) + c-Myc<br />
+
-
[[1ee5]] – yIPO NLS-binding domain (mutant) + nucleoplasmin<br />
+
-
[[1un0]], [[2c1t]] – yIPO NLS-binding domain (mutant) + Nup2<br />
+
-
 
+
-
''IPO-α complex with protein''
+
-
 
+
-
[[1wa5]] – yIPO NLS-binding domain + GTPase Ran + IPO-α re-exporter<br />
+
-
 
+
-
'''IPO-α 1'''
+
-
 
+
-
''IPO-α 1 complex with NLS peptide''
+
-
 
+
-
[[4mz5]], [[4mz6]] – mIPO NLS-binding domain + dUTPase<br />
+
-
[[4oih]] – mIPO NLS-binding domain + guanine nucleotide exchange factor SRM1<br />
+
-
 
+
-
''IPO-α 1 complex with protein''
+
-
 
+
-
[[2jdq]] – hIPO NLS-binding domain + polymerase basic protein 2 C terminal<br />
+
-
[[3tj3]] – hIPO NLS-binding domain + Nup50 N terminal<br />
+
-
[[2jdq]] – hIPO NLS-binding domain + telomerase reverse transcriptase peptide<br />
+
-
 
+
-
'''IPO-α 2'''
+
-
 
+
-
[[3tpo]] – mIPO<br />
+
-
[[1iq1]] – mIPO NLS-binding + autoinhibitory peptide domains<br />
+
-
[[4e4v]] – hIPO NLS-binding domain (mutant) - human <br />
+
-
 
+
-
''IPO-α 2 complex with NLS peptide''
+
-
 
+
-
[[1pjm]] – mIPO NLS-binding domain + retinoblastoma-associated protein<br />
+
-
[[1pjn]] – mIPO NLS-binding domain + histone-binding protein N1/N2<br />
+
-
[[1q1s]], [[1q1t]] – mIPO NLS-binding domain + SV40 large T antigen<br />
+
-
[[1y2a]], [[3q5u]] – mIPO NLS-binding domain + phospholipid scramblase <br />
+
-
[[2c1m]] – mIPO NLS-binding domain + Nup50<br />
+
-
[[3btr]] – mIPO NLS-binding domain + androgen receptor<br />
+
-
[[3knd]] – mIPO NLS-binding domain + targeting protein for KXLP2<br />
+
-
[[3l3q]] – mIPO NLS-binding domain + library peptide<br />
+
-
[[3oqs]] – mIPO NLS-binding domain + CLIC4<br />
+
-
[[3rz9]] – mIPO NLS-binding domain + KU80<br />
+
-
[[3rzx]] – mIPO NLS-binding domain + KU70<br />
+
-
[[3tpm]] – mIPO NLS-binding domain + MAL<br />
+
-
[[3ve6]] – mIPO NLS-binding domain + Venezuelan equine encephalitis virus<br />
+
-
[[3uvu]] – mIPO NLS-binding domain + flap endonuclease<br />
+
-
[[3ukw]], [[3ukx]] – mIPO NLS-binding domain + BIMAX<br />
+
-
[[3uky]], [[3ukz]], [[3ul0]] – mIPO NLS-binding domain + nuclear CAP-binding protein<br />
+
-
[[3ul1]] – mIPO NLS-binding domain + nucleoplasmin <br />
+
-
[[4htv]] – mIPO NLS-binding domain + capsid protein <br />
+
-
[[4ba3]] – mIPO NLS-binding domain + A89NLS <br />
+
-
[[3zio]], [[3zip]], [[3ziq]], [[3zir]] – mIPO NLS-binding domain + minor site-specific NLS <br />
+
-
[[3zin]] – mIPO NLS-binding domain + nucleolar RNA helicase<br />
+
-
 
+
-
''IPO-α 2 complex with protein''
+
-
 
+
-
[[3fex]], [[3fey]] – mIPO NLS-binding domain + nuclear CAP-binding protein<br />
+
-
 
+
-
'''IPO-β 1'''
+
-
 
+
-
[[3nd2]] – yIPO <br />
+
-
[[1gcj]] – mIPO N terminal<br />
+
-
 
+
-
''IPO-β 1 complex with protein''
+
-
 
+
-
[[1qgx]], [[1qgr]] – hIPO + IPO-α 2 IBB domain<br />
+
-
[[1ibr]] – hIPO + GTPase Ran<br />
+
-
[[2bku]], [[3ea5]] – yIPO + GTPase Ran<br />
+
-
[[1f59]], [[1o6p]], [[1o6o]] – hIPO + FXFG nucleoporin repeats<br />
+
-
[[1m5n]] – hIPO HEAT repeats 1-11 + parathyroid hormone-related protein NLS peptide<br />
+
-
[[2p8q]], [[2q5d]], [[2qna]], [[3lww]] – hIPO + RNA U transporter N terminal<br />
+
-
[[1qgr]], [[3w5k]] – hIPO + zinc finger protein SNAI1<br />
+
-
[[2bpt]] – yIPO + Nup1<br />
+
-
[[1ukl]] – mIPO + SREBP-2<br />
+
-
 
+
-
'''IPO-β 2 (Transportin 1)'''
+
-
 
+
-
[[2z5j]], [[2qmr]] – hIPO <br />
+
-
 
+
-
''IPO-β 2 complex with protein''
+
-
 
+
-
[[2h4m]], [[2ot8]], [[2z5n]] – hIPO + hnRNP peptide<br />
+
-
[[2z5k]], [[2z5m]] – hIPO + nuclear RNA export factor peptide<br />
+
-
[[2z5o]] – hIPO + JKTBP peptide<br />
+
-
[[4fdd]], [[4jlq]], [[4oo6]] – hIPO + RNA binding protein peptide<br />
+
-
[[4fq3]] – hIPO + FUS peptide<br />
+
-
 
+
-
'''IPO-13'''
+
-
 
+
-
[[2x19]] – hIPO + GTPase Ran<br />
+
-
[[2xwu]] – hIPO + UBC9<br />
+
-
[[3zjy]] – hIPO + GTPase Ran + EIF-1A<br />
+
-
 
+
== References ==
== References ==

Current revision

Structure of yeast importin α NLS-binding domain (grey) complex with nucleoplasmin peptide (green) (PDB code 1ee5).

Drag the structure with the mouse to rotate

References

  1. ↑ Mattaj IW, Englmeier L. Nucleocytoplasmic transport: the soluble phase. Annu Rev Biochem. 1998;67:265-306. PMID:9759490 doi:http://dx.doi.org/10.1146/annurev.biochem.67.1.265
  2. ↑ Bernardes NE, Fung HYJ, Li Y, Chen Z, Chook YM. Structure of IMPORTIN-4 bound to the H3-H4-ASF1 histone-histone chaperone complex. Proc Natl Acad Sci U S A. 2022 Sep 20;119(38):e2207177119. PMID:36103578 doi:10.1073/pnas.2207177119
  3. ↑ García-García M, Sánchez-Perales S, Jarabo P, Calvo E, Huyton T, Fu L, Ng SC, Sotodosos-Alonso L, Vázquez J, Casas-Tintó S, Görlich D, Echarri A, Del Pozo MA. Mechanical control of nuclear import by Importin-7 is regulated by its dominant cargo YAP. Nat Commun. 2022 Mar 4;13(1):1174. PMID:35246520 doi:10.1038/s41467-022-28693-y
  4. ↑ Padavannil A, Sarkar P, Kim SJ, Cagatay T, Jiou J, Brautigam CA, Tomchick DR, Sali A, D'Arcy S, Chook YM. Importin-9 wraps around the H2A-H2B core to act as nuclear importer and histone chaperone. Elife. 2019 Mar 11;8. pii: 43630. doi: 10.7554/eLife.43630. PMID:30855230 doi:http://dx.doi.org/10.7554/eLife.43630
  5. ↑ Gajewska KA, Lescesen H, Ramialison M, Wagstaff KM, Jans DA. Nuclear transporter Importin-13 plays a key role in the oxidative stress transcriptional response. Nat Commun. 2021 Oct 8;12(1):5904. PMID:34625540 doi:10.1038/s41467-021-26125-x
  6. ↑ Pumroy RA, Cingolani G. Diversification of importin-alpha isoforms in cellular trafficking and disease states. Biochem J. 2015 Feb 15;466(1):13-28. doi: 10.1042/BJ20141186. PMID:25656054 doi:http://dx.doi.org/10.1042/BJ20141186

Proteopedia Page Contributors and Editors (what is this?)

Michal Harel, Joel L. Sussman

Retrieved from "http://52.214.119.220/wiki/index.php/Importin"
Personal tools