Genome-wide mapping of RELA(p65) binding identifies E2F1 as a transcriptional activator recruited by NF-kappaB upon TLR4 activation.
NF-kappaB is a key mediator of inflammation. Here, we mapped the genome-wide loci bound by the RELA subunit of NF-kappaB in lipopolysaccharide (LPS)-stimulated human monocytic cells, and together with global gene expression profiling, found an overrepresentation of the E2F1-binding motif among RELA-bound loci associated with NF-kappaB target genes. Knockdown of endogenous E2F1 impaired the LPS inducibility of the proinflammatory cytokines CCL3(MIP-1alpha), IL23A(p19), TNF-alpha, and IL1-beta. Upon LPS stimulation, E2F1 is rapidly recruited to the promoters of these genes along with p50/RELA heterodimer via a mechanism that is dependent on NF-kappaB activation. Together with the observation that E2F1 physically interacts with p50/RELA in LPS-stimulated cells, our findings suggest that NF-kappaB recruits E2F1 to fully activate the transcription of NF-kappaB target genes. Global gene expression profiling subsequently revealed a spectrum of NF-kappaB target genes that are positively regulated by E2F1, further demonstrating the critical role of E2F1 in the Toll-like receptor 4 pathway.
Lim
Ching-Aeng
CA
Laboratory of Immunology and Virology, Genome Institute of Singapore, 138672 Singapore.
Yao
Fei
F
Wong
Joyce Jing-Yi
JJ
George
Joshy
J
Xu
Han
H
Chiu
Kuo Ping
KP
Sung
Wing-Kin
WK
Lipovich
Leonard
L
Vega
Vinsensius B
VB
Chen
Joanne
J
Shahab
Atif
A
Zhao
Xiao Dong
XD
Hibberd
Martin
M
Wei
Chia-Lin
CL
Lim
Bing
B
Ng
Huck-Hui
HH
Ruan
Yijun
Y
Chin
Keh-Chuang
KC
D020816:Amino Acid Motifs; D001483:Base Sequence; D001665:Binding Sites; D002460:Cell Line; D002467:Cell Nucleus / Q000187:drug effects / Q000378:metabolism; D016384:Consensus Sequence; D016207:Cytokines / Q000378:metabolism; D050687:E2F1 Transcription Factor / Q000378:metabolism*; D005786:Gene Expression Regulation / Q000187:drug effects; D015894:Genome, Human / Q000235:genetics*; D006801:Humans; D018836:Inflammation Mediators / Q000378:metabolism; D008070:Lipopolysaccharides / Q000494:pharmacology; D008969:Molecular Sequence Data; D011485:Protein Binding / Q000187:drug effects; D021381:Protein Transport / Q000187:drug effects; D016160:Retinoblastoma Protein / Q000378:metabolism; D051197:Toll-Like Receptor 4 / Q000378:metabolism*; D015534:Trans-Activators / Q000378:metabolism*; D051996:Transcription Factor RelA / Q000378:metabolism*
D016207:Cytokines; D050687:E2F1 Transcription Factor; D018836:Inflammation Mediators; D008070:Lipopolysaccharides; D016160:Retinoblastoma Protein; C495345:TLR4 protein, human; D051197:Toll-Like Receptor 4; D015534:Trans-Activators; D051996:Transcription Factor RelA