PDBsum entry 1iq1

Protein transport

PDB id

1iq1

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Contents

			Protein chain

					426 a.a. *

			Ligands

					MET-LEU-LYS-ARG- ARG-ASN-VAL


					GLU-ASN-MET-LEU- LYS-ARG-ARG-ASN- VAL

			Waters ×95

* Residue conservation analysis

PDB id:

1iq1

Links

Name:

Protein transport

Title:

Crystal structure of the importin-alpha(44-54)-importin-alpha(70-529) complex

Structure:

Importin alpha-2 subunit. Chain: a, b. Fragment: autoinhibitory peptide(residues 44-54). Engineered: yes. Importin alpha-2 subunit. Chain: c. Fragment: armadillo repeat domain(residues 70-529). Engineered: yes

Source:

Synthetic: yes. Other_details: peptide synthesis. Mus musculus. House mouse. Organism_taxid: 10090. Expressed in: escherichia coli. Expression_system_taxid: 562

Biol. unit:

Trimer (from PQS)

Resolution:

2.80Å

R-factor:

0.209

R-free:

0.248

Authors:

B.Catimel,T.Teh,M.R.M.Fontes,I.G.Jennings,B.Kobe

Key ref:

B.Catimel et al. (2001). Biophysical characterization of interactions involving importin-alpha during nuclear import. J Biol Chem, 276, 34189-34198. PubMed id: 11448961 DOI: 10.1074/jbc.M103531200

Date:

28-May-01

Release date:

14-Nov-01

PROCHECK

	Headers

	References

Protein chain

P52293 (IMA1_MOUSE) - Importin subunit alpha-1 from Mus musculus

Seq: Struc:

Seq: Struc:					529 a.a. 426 a.a.

Key:

PfamA domain

Secondary structure

CATH domain

DOI no: 10.1074/jbc.M103531200	J Biol Chem 276:34189-34198 (2001)
PubMed id: 11448961

Biophysical characterization of interactions involving importin-alpha during nuclear import.
B.Catimel, T.Teh, M.R.Fontes, I.G.Jennings, D.A.Jans, G.J.Howlett, E.C.Nice, B.Kobe.

ABSTRACT

Proteins containing the classical nuclear localization sequences (NLSs) are imported into the nucleus by the importin-alpha/beta heterodimer. Importin-alpha contains the NLS binding site, whereas importin-beta mediates the translocation through the nuclear pore. We characterized the interactions involving importin-alpha during nuclear import using a combination of biophysical techniques (biosensor, crystallography, sedimentation equilibrium, electrophoresis, and circular dichroism). Importin-alpha is shown to exist in a monomeric autoinhibited state (association with NLSs undetectable by biosensor). Association with importin-beta (stoichiometry, 1:1; K(D) = 1.1 x 10(-8) m) increases the affinity for NLSs; the importin-alpha/beta complex binds representative monopartite NLS (simian virus 40 large T-antigen) and bipartite NLS (nucleoplasmin) with affinities (K(D) = 3.5 x 10(-8) m and 4.8 x 10(-8) m, respectively) comparable with those of a truncated importin-alpha lacking the autoinhibitory domain (T-antigen NLS, K(D) = 1.7 x 10(-8) m; nucleoplasmin NLS, K(D) = 1.4 x 10(-8) m). The autoinhibitory domain (as a separate peptide) binds the truncated importin-alpha, and the crystal structure of the complex resembles the structure of full-length importin-alpha. Our results support the model of regulation of nuclear import mediated by the intrasteric autoregulatory sequence of importin-alpha and provide a quantitative description of the binding and regulatory steps during nuclear import.

Selected figure(s)



	Figure 5. Fig. 5. Crystal structure of the complex between Imp (44-54) and Imp (70-529). A, stereoview of the electron density (drawn with the program BOBSCRIPT (52)) in the region of the peptide bound to the major binding site of Imp (70-529). All peptide residues were omitted from the model and simulated annealing run with the starting temperature of 1000 K. The electron density map was calculated with coefficients 3\|F[obs]\| 2\|F[calc]\| and data between 30 and 2.8 Å resolution and contoured at 1.3 standard deviations. Superimposed is the refined model of the peptide. B, schematic diagram of the complex. Importin- is shown as a ribbon diagram (yellow; drawn with program RIBBONS (53)). The superhelical axis of the repetitive part of the molecule is approximately horizontal. The two peptides are shown in a ball-and-stick representation; the peptide bound to the major site is colored cyan, and the peptide bound to the minor site is colored red. C, superposition of the Imp (44-54) peptide (cyan) and the corresponding region of full-length importin (magenta) bound to the major NLS-binding site of importin- . The C atoms of residues 70-496 were used in the superposition (drawn with the program RIBBONS (53)).		Figure 7. Fig. 7. Schematic diagram of the NLS-dependent nuclear import pathway. Yellow, importin- ; green, importin- ; cyan, NLS-containing cargo protein; magenta, Ran-GTP. For simplicity, other factors involved in the pathway such as nuclear transport factor-2, the nuclear export receptor for importin- , and Ran-binding proteins have been omitted from the diagram. Dissociation constants for the different binding events are shown.

Figures were selected by an automated process.

Literature references that cite this PDB file's key reference

PubMed id

Reference

20857408

E.Purev, D.R.Soprano, and K.J.Soprano (2011).
PP2A interaction with Rb2/p130 mediates translocation of Rb2/p130 into the nucleus in all-trans retinoic acid-treated ovarian carcinoma cells.

J Cell Physiol, 226, 1027-1034.

21481773

T.L.Yeh, C.Y.Lee, L.M.Amzel, P.J.Espenshade, and M.A.Bianchet (2011).
The hypoxic regulator of sterol synthesis nro1 is a nuclear import adaptor.

Structure, 19, 503-514.

PDB code:

3msv

20335181

A.Giesecke, and M.Stewart (2010).
Novel binding of the mitotic regulator TPX2 (target protein for xenopus kinesin-like protein 2) to importin-alpha.

J Biol Chem, 285, 17628-17635.

PDB code:

3knd

21179018

A.N.Kolodkin, F.J.Bruggeman, N.Plant, M.J.Moné, B.M.Bakker, M.J.Campbell, J.P.van Leeuwen, C.Carlberg, J.L.Snoep, and H.V.Westerhoff (2010).
Design principles of nuclear receptor signaling: how complex networking improves signal transduction.

Mol Syst Biol, 6, 446.

19785068

A.S.Sobolev (2009).
Novel modular transporters delivering anticancer drugs and foreign DNA to the nuclei of target cancer cells.

J BUON, 14, S33-S42.

19858191

F.Cardarelli, R.Bizzarri, M.Serresi, L.Albertazzi, and F.Beltram (2009).
Probing nuclear localization signal-importin alpha binding equilibria in living cells.

J Biol Chem, 284, 36638-36646.

19366694

K.E.Süel, and Y.M.Chook (2009).
Kap104p imports the PY-NLS-containing transcription factor Tfg2p into the nucleus.

J Biol Chem, 284, 15416-15424.

19794817

R.B.Kopito, and M.Elbaum (2009).
Nucleocytoplasmic transport: a thermodynamic mechanism.

HFSP J, 3, 130-141.

19549784

T.G.Lonhienne, J.K.Forwood, M.Marfori, G.Robin, B.Kobe, and B.J.Carroll (2009).
Importin-beta is a GDP-to-GTP exchange factor of Ran: implications for the mechanism of nuclear import.

J Biol Chem, 284, 22549-22558.

18293370

A.S.Sobolev (2008).
Modular transporters for subcellular cell-specific targeting of anti-tumor drugs.

Bioessays, 30, 278-287.

18562297

C.Sun, W.Yang, L.C.Tu, and S.M.Musser (2008).
Single-molecule measurements of importin alpha/cargo complex dissociation at the nuclear pore.

Proc Natl Acad Sci U S A, 105, 8613-8618.

18532879

K.E.Süel, H.Gu, and Y.M.Chook (2008).
Modular organization and combinatorial energetics of proline-tyrosine nuclear localization signals.

PLoS Biol, 6, e137.

18547523

U.Zachariae, and H.Grubmüller (2008).
Importin-beta: structural and dynamic determinants of a molecular spring.

Structure, 16, 906-915.

17056062

A.Paradise, M.K.Levin, G.Korza, and J.H.Carson (2007).
Significant proportions of nuclear transport proteins with reduced intracellular mobilities resolved by fluorescence correlation spectroscopy.

J Mol Biol, 365, 50-65.

17089387

M.A.Yucel, and I.A.Kurnaz (2007).
An in silico model for HIF-alpha regulation and hypoxia response in tumor cells.

Biotechnol Bioeng, 97, 588-600.

17287812

M.Stewart (2007).
Molecular mechanism of the nuclear protein import cycle.

Nat Rev Mol Cell Biol, 8, 195-208.

17646647

R.B.Kopito, and M.Elbaum (2007).
Reversibility in nucleocytoplasmic transport.

Proc Natl Acad Sci U S A, 104, 12743-12748.

16421734

A.S.Madrid, and K.Weis (2006).
Nuclear transport is becoming crystal clear.

Chromosoma, 115, 98.

17000757

B.Friedrich, C.Quensel, T.Sommer, E.Hartmann, and M.Köhler (2006).
Nuclear localization signal and protein context both mediate importin alpha specificity of nuclear import substrates.

Mol Cell Biol, 26, 8697-8709.

17116750

B.L.Timney, J.Tetenbaum-Novatt, D.S.Agate, R.Williams, W.Zhang, B.T.Chait, and M.P.Rout (2006).
Simple kinetic relationships and nonspecific competition govern nuclear import rates in vivo.

J Cell Biol, 175, 579-593.

16552788

E.Blazek, and M.Meisterernst (2006).
A functional proteomics approach for the detection of nuclear proteins based on derepressed importin alpha.

Proteomics, 6, 2070-2078.

16936753

K.J.Soprano, E.Purev, S.Vuocolo, and D.R.Soprano (2006).
Rb2/p130 and protein phosphatase 2A: key mediators of ovarian carcinoma cell growth suppression by all-trans retinoic acid.

Oncogene, 25, 5315-5325.

16345111

S.Schlummer, R.Vetter, N.Kuder, A.Henkel, Y.X.Chen, Y.M.Li, J.Kuhlmann, and H.Waldmann (2006).
Influence of serine O-glycosylation or O-phosphorylation close to the vJun nuclear localisation sequence on nuclear import.

Chembiochem, 7, 88-97.

16982803

W.Yang, and S.M.Musser (2006).
Nuclear import time and transport efficiency depend on importin beta concentration.

J Cell Biol, 174, 951-961.

16879979

W.Yang, and S.M.Musser (2006).
Visualizing single molecules interacting with nuclear pore complexes by narrow-field epifluorescence microscopy.

Methods, 39, 316-328.

15795315

G.Riddick, and I.G.Macara (2005).
A systems analysis of importin-{alpha}-{beta} mediated nuclear protein import.

J Cell Biol, 168, 1027-1038.

16167204

K.M.Wagstaff, M.M.Dias, G.Alvisi, and D.A.Jans (2005).
Quantitative analysis of protein-protein interactions by native page/fluorimaging.

J Fluoresc, 15, 469-473.

16103202

R.R.Rowland, V.Chauhan, Y.Fang, A.Pekosz, M.Kerrigan, and M.D.Burton (2005).
Intracellular localization of the severe acute respiratory syndrome coronavirus nucleocapsid protein: absence of nucleolar accumulation during infection and after expression as a recombinant protein in vero cells.

J Virol, 79, 11507-11512.

16222336

Y.Matsuura, and M.Stewart (2005).
Nup50/Npap60 function in nuclear protein import complex disassembly and importin recycling.

EMBO J, 24, 3681-3689.

PDB codes:

2c1m 2c1t

15350979

D.S.Goldfarb, A.H.Corbett, D.A.Mason, M.T.Harreman, and S.A.Adam (2004).
Importin alpha: a multipurpose nuclear-transport receptor.

Trends Cell Biol, 14, 505-514.

15351969

H.M.Johnson, P.S.Subramaniam, S.Olsnes, and D.A.Jans (2004).
Trafficking and signaling pathways of nuclear localizing protein ligands and their receptors.

Bioessays, 26, 993.

13679510

S.C.Ems-McClung, Y.Zheng, and C.E.Walczak (2004).
Importin alpha/beta and Ran-GTP regulate XCTK2 microtubule binding through a bipartite nuclear localization signal.

Mol Biol Cell, 15, 46-57.

15057270

T.Sekimoto, M.Fukumoto, and Y.Yoneda (2004).
14-3-3 suppresses the nuclear localization of threonine 157-phosphorylated p27(Kip1).

EMBO J, 23, 1934-1942.

12626763

C.M.House, I.J.Frew, H.L.Huang, G.Wiche, N.Traficante, E.Nice, B.Catimel, and D.D.Bowtell (2003).
A binding motif for Siah ubiquitin ligase.

Proc Natl Acad Sci U S A, 100, 3101-3106.

14532109

Y.Matsuura, A.Lange, M.T.Harreman, A.H.Corbett, and M.Stewart (2003).
Structural basis for Nup2p function in cargo release and karyopherin recycling in nuclear import.

EMBO J, 22, 5358-5369.

PDB code:

1un0

12142282

M.A.Pufall, and B.J.Graves (2002).
Autoinhibitory domains: modular effectors of cellular regulation.

Annu Rev Cell Dev Biol, 18, 421-462.

11854401

N.Panté, and M.Kann (2002).
Nuclear pore complex is able to transport macromolecules with diameters of about 39 nm.

Mol Biol Cell, 13, 425-434.

12501157

R.L.Rich, and D.G.Myszka (2002).
Survey of the year 2001 commercial optical biosensor literature.

J Mol Recognit, 15, 352-376.

12370244

S.K.Lyman, T.Guan, J.Bednenko, H.Wodrich, and L.Gerace (2002).
Influence of cargo size on Ran and energy requirements for nuclear protein import.

J Cell Biol, 159, 55-67.

The most recent references are shown first. Citation data come partly from CiteXplore and partly from an automated harvesting procedure. Note that this is likely to be only a partial list as not all journals are covered by either method. However, we are continually building up the citation data so more and more references will be included with time. Where a reference describes a PDB structure, the PDB code is shown on the right.