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PDBsum entry 1ukh
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Contents |
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* Residue conservation analysis
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References listed in PDB file
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Key reference
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Title
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Structural basis for the selective inhibition of jnk1 by the scaffolding protein jip1 and sp600125.
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Authors
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Y.S.Heo,
S.K.Kim,
C.I.Seo,
Y.K.Kim,
B.J.Sung,
H.S.Lee,
J.I.Lee,
S.Y.Park,
J.H.Kim,
K.Y.Hwang,
Y.L.Hyun,
Y.H.Jeon,
S.Ro,
J.M.Cho,
T.G.Lee,
C.H.Yang.
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Ref.
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EMBO J, 2004,
23,
2185-2195.
[DOI no: ]
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PubMed id
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Abstract
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The c-jun N-terminal kinase (JNK) signaling pathway is regulated by
JNK-interacting protein-1 (JIP1), which is a scaffolding protein assembling the
components of the JNK cascade. Overexpression of JIP1 deactivates the JNK
pathway selectively by cytoplasmic retention of JNK and thereby inhibits gene
expression mediated by JNK, which occurs in the nucleus. Here, we report the
crystal structure of human JNK1 complexed with pepJIP1, the peptide fragment of
JIP1, revealing its selectivity for JNK1 over other MAPKs and the allosteric
inhibition mechanism. The van der Waals contacts by the three residues (Pro157,
Leu160, and Leu162) of pepJIP1 and the hydrogen bonding between Glu329 of JNK1
and Arg156 of pepJIP1 are critical for the selective binding. Binding of the
peptide also induces a hinge motion between the N- and C-terminal domains of
JNK1 and distorts the ATP-binding cleft, reducing the affinity of the kinase for
ATP. In addition, we also determined the ternary complex structure of
pepJIP1-bound JNK1 complexed with SP600125, an ATP-competitive inhibitor of JNK,
providing the basis for the JNK specificity of the compound.
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Figure 4.
Figure 4 Distortion of the ATP-binding site caused by
interdomain rearrangement upon pepJIP1 binding. (A) Structural
comparison between JNK3 (green) and pepJIP1-bound JNK1 (violet)
when the C-terminal domains of the kinases are superimposed. The
conformational differences of the N-terminal domains can be
easily distinguished when the conventional view of kinases is
rotated by 45° along the horizontal axis. The yellow circle
indicates the interaction between the  1
helix and the phosphorylation loop in JNK3, but not existing in
JNK1 complexed with pepJIP1. (B) Comparison of ATP-binding sites
between the JNK1 -pepJIP1 (violet) and JNK3 -AMPPNP (green)
complexes. The AMPPNP bound in JNK3 is shown in a ball-and-stick
model. The residues of JNK3 involved in the hydrogen bonding
with AMPPNP are labeled. The side chains of the residues in the
glycine-rich loop including E75 and A74 of JNK3 are omitted for
clarity because the backbone amide groups only are involved in
the hydrogen bonds with the phosphate groups of AMPPNP. (C) The
structural comparison of the residues crucial for the catalytic
activity between the JNK1 -pepJIP1 (violet) and JNK3 -AMPPNP
(green) complexes. The residues in JNK1 and JNK3 are labeled red
and black, respectively. In (B, C), hydrogen bonds are indicated
by dashed lines.
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Figure 5.
Figure 5 The inhibited phosphorylation of MBP, the docking
site-independent substrate, due to the reduced ATP binding
affinity to JNK1 by pepJIP1 binding. (A, B) The binding
affinities of ATP to JNK1 were measured by ITC when pepJIP1 was
unbound (A) and bound (B) to JNK1. (C) Dose-dependent inhibition
of the kinase activity of JNK1 by pepJIP1 using MBP as
substrates. The mutated pepJIP1 used for control experiment has
the sequence of RPKAATTANAF.
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The above figures are
reprinted
from an Open Access publication published by Macmillan Publishers Ltd:
EMBO J
(2004,
23,
2185-2195)
copyright 2004.
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