ジャーナル: J Biol Chem / 年: 2018 タイトル: Picomolar zinc binding modulates formation of Bcl10-nucleating assemblies of the caspase recruitment domain (CARD) of CARD9. 著者: Michael J Holliday / Ryan Ferrao / Gladys de Leon Boenig / Alberto Estevez / Elizabeth Helgason / Alexis Rohou / Erin C Dueber / Wayne J Fairbrother / 要旨: The caspase recruitment domain-containing protein 9 (CARD9)-B-cell lymphoma/leukemia 10 (Bcl10) signaling axis is activated in myeloid cells during the innate immune response to a variety of diverse ...The caspase recruitment domain-containing protein 9 (CARD9)-B-cell lymphoma/leukemia 10 (Bcl10) signaling axis is activated in myeloid cells during the innate immune response to a variety of diverse pathogens. This signaling pathway requires a critical caspase recruitment domain (CARD)-CARD interaction between CARD9 and Bcl10 that promotes downstream activation of factors, including NF-κB and the mitogen-activated protein kinase (MAPK) p38. Despite these insights, CARD9 remains structurally uncharacterized, and little mechanistic understanding of its regulation exists. We unexpectedly found here that the CARD in CARD9 binds to Zn with picomolar affinity-a concentration comparable with the levels of readily accessible Zn in the cytosol. NMR solution structures of the CARD9-CARD in the apo and Zn-bound states revealed that Zn has little effect on the ground-state structure of the CARD; yet the stability of the domain increased considerably upon Zn binding, with a concomitant reduction in conformational flexibility. Moreover, Zn binding inhibited polymerization of the CARD9-CARD into helical assemblies. Here, we also present a 20-Å resolution negative-stain EM (NS-EM) structure of these filamentous assemblies and show that they adopt a similar helical symmetry as reported previously for filaments of the Bcl10 CARD. Using both bulk assays and direct NS-EM visualization, we further show that the CARD9-CARD assemblies can directly template and thereby nucleate Bcl10 polymerization, a capacity considered critical to propagation of the CARD9-Bcl10 signaling cascade. Our findings indicate that CARD9 is a potential target of Zn-mediated signaling that affects Bcl10 polymerization in innate immune responses.
A: 120.36 Å / B: 120.36 Å / C: 401.2 Å α=β=γ: 90.0 °
CCP4マップ ヘッダ情報:
mode
Image stored as Reals
Å/pix. X/Y/Z
2.006
2.006
2.006
M x/y/z
60
60
200
origin x/y/z
0.000
0.000
0.000
length x/y/z
120.360
120.360
401.200
α/β/γ
90.000
90.000
90.000
start NX/NY/NZ
0
0
0
NX/NY/NZ
240
240
240
MAP C/R/S
1
2
3
start NC/NR/NS
-30
-30
-100
NC/NR/NS
60
60
200
D min/max/mean
-0.133
1.483
0.107
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添付データ
-
試料の構成要素
-
全体 : Helical filament of the CARD9 CARD
全体
名称: Helical filament of the CARD9 CARD
要素
複合体: Helical filament of the CARD9 CARD
タンパク質・ペプチド: CARD9 CARD
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超分子 #1: Helical filament of the CARD9 CARD
超分子
名称: Helical filament of the CARD9 CARD / タイプ: complex / ID: 1 / 親要素: 0 / 含まれる分子: all 詳細: Generated by stripping Zn from 0.2 mM 1:1 CARD:Zn with 0.25 mM EDTA, followed by shaking for 90 minutes at 25C