TY - JOUR
T1 - N4BP1 negatively regulates NF-κB by binding and inhibiting NEMO oligomerization
AU - Shi, Hexin
AU - Sun, Lei
AU - Wang, Ying
AU - Liu, Aijie
AU - Zhan, Xiaoming
AU - Li, Xiaohong
AU - Tang, Miao
AU - Anderton, Priscilla
AU - Hildebrand, Sara
AU - Quan, Jiexia
AU - Ludwig, Sara
AU - Moresco, Eva Marie Y.
AU - Beutler, Bruce
N1 - Funding Information:
We thank Hong Zhang (University of Texas Southwestern Medical Center) for helpful suggestions. This work was supported by the National Institutes of Health grants R01 AI125581 and U19 AI100627 (to B.B.) and by the Lyda Hill Foundation. H.S., Y.W., X.Z., X.L., M.T., P.A., S.H., J.Q., S.L., and B.B. received salary support from Pfizer, Inc.
Publisher Copyright:
© 2021, The Author(s).
PY - 2021/12
Y1 - 2021/12
N2 - Many immune responses depend upon activation of NF-κB, an important transcription factor in the elicitation of a cytokine response. Here we show that N4BP1 inhibits TLR-dependent activation of NF-κB by interacting with the NF-κB signaling essential modulator (NEMO, also known as IκB kinase γ) to attenuate NEMO–NEMO dimerization or oligomerization. The UBA-like (ubiquitin associated-like) and CUE-like (ubiquitin conjugation to ER degradation-like) domains in N4BP1 mediate interaction with the NEMO COZI domain. Both in vitro and in mice, N4bp1 deficiency specifically enhances TRIF-independent (TLR2, TLR7, or TLR9-mediated) but not TRIF-dependent (TLR3 or TLR4-mediated) NF-κB activation, leading to increased production of proinflammatory cytokines. In response to TLR4 or TLR3 activation, TRIF causes activation of caspase-8, which cleaves N4BP1 distal to residues D424 and D490 and abolishes its inhibitory effect. N4bp1−/− mice also have diminished numbers of T cells in the peripheral blood. Our work identifies N4BP1 as an inhibitory checkpoint protein that must be overcome to activate NF-κB, and a TRIF-initiated caspase-8-dependent mechanism by which this is accomplished.
AB - Many immune responses depend upon activation of NF-κB, an important transcription factor in the elicitation of a cytokine response. Here we show that N4BP1 inhibits TLR-dependent activation of NF-κB by interacting with the NF-κB signaling essential modulator (NEMO, also known as IκB kinase γ) to attenuate NEMO–NEMO dimerization or oligomerization. The UBA-like (ubiquitin associated-like) and CUE-like (ubiquitin conjugation to ER degradation-like) domains in N4BP1 mediate interaction with the NEMO COZI domain. Both in vitro and in mice, N4bp1 deficiency specifically enhances TRIF-independent (TLR2, TLR7, or TLR9-mediated) but not TRIF-dependent (TLR3 or TLR4-mediated) NF-κB activation, leading to increased production of proinflammatory cytokines. In response to TLR4 or TLR3 activation, TRIF causes activation of caspase-8, which cleaves N4BP1 distal to residues D424 and D490 and abolishes its inhibitory effect. N4bp1−/− mice also have diminished numbers of T cells in the peripheral blood. Our work identifies N4BP1 as an inhibitory checkpoint protein that must be overcome to activate NF-κB, and a TRIF-initiated caspase-8-dependent mechanism by which this is accomplished.
UR - http://www.scopus.com/inward/record.url?scp=85101974897&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85101974897&partnerID=8YFLogxK
U2 - 10.1038/s41467-021-21711-5
DO - 10.1038/s41467-021-21711-5
M3 - Article
C2 - 33654074
AN - SCOPUS:85101974897
VL - 12
JO - Nature Communications
JF - Nature Communications
SN - 2041-1723
IS - 1
M1 - 1379
ER -