Intermolecular binding between TIFA-FHA and TIFA-pT mediates tumor necrosis factor alpha stimulation and NF-κB activation

Chia-Chi Flora Huang; Jui-Hung Weng; Tong-You Wade Wei; Pei-Yu Gabriel Wu; Pang-Hung Hsu; Yu-Hou Chen; Shun-Chang Wang; Dongyan Qin; Chin-Chun Hung; Shui-Tsung Chen; Andrew H-J Wang; John Y-J Shyy; Ming-Daw Tsai

doi:10.1128/MCB.00438-12

Intermolecular binding between TIFA-FHA and TIFA-pT mediates tumor necrosis factor alpha stimulation and NF-κB activation

Mol Cell Biol. 2012 Jul;32(14):2664-73. doi: 10.1128/MCB.00438-12. Epub 2012 May 7.

Authors

Chia-Chi Flora Huang¹, Jui-Hung Weng, Tong-You Wade Wei, Pei-Yu Gabriel Wu, Pang-Hung Hsu, Yu-Hou Chen, Shun-Chang Wang, Dongyan Qin, Chin-Chun Hung, Shui-Tsung Chen, Andrew H-J Wang, John Y-J Shyy, Ming-Daw Tsai

Affiliation

¹ Institute of Biological Chemistry, Academia Sinica, Taipei, Taiwan.

Abstract

The forkhead-associated (FHA) domain recognizes phosphothreonine (pT) with high specificity and functional diversity. TIFA (TRAF-interacting protein with an FHA domain) is the smallest FHA-containing human protein. Its overexpression was previously suggested to provoke NF-κB activation, yet its exact roles in this signaling pathway and the underlying molecular mechanism remain unclear. Here we identify a novel threonine phosphorylation site on TIFA and show that this phosphorylated threonine (pT) binds with the FHA domain of TIFA, leading to TIFA oligomerization and TIFA-mediated NF-κB activation. Detailed analysis indicated that unphosphorylated TIFA exists as an intrinsic dimer and that the FHA-pT9 binding occurs between different dimers of TIFA. In addition, silencing of endogenous TIFA resulted in attenuation of tumor necrosis factor alpha (TNF-α)-mediated downstream signaling. We therefore propose that the TIFA FHA-pT9 binding provides a previously unidentified link between TNF-α stimulation and NF-κB activation. The intermolecular FHA-pT9 binding between dimers also represents a new mechanism for the FHA domain.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Adaptor Proteins, Signal Transducing / antagonists & inhibitors
Adaptor Proteins, Signal Transducing / chemistry*
Adaptor Proteins, Signal Transducing / genetics
Adaptor Proteins, Signal Transducing / metabolism*
Amino Acid Sequence
Amino Acid Substitution
Antibodies, Monoclonal
Forkhead Transcription Factors / chemistry
Forkhead Transcription Factors / metabolism
HEK293 Cells
Humans
Models, Biological
Molecular Sequence Data
Mutant Proteins / chemistry
Mutant Proteins / genetics
Mutant Proteins / metabolism
NF-kappa B / metabolism*
Phosphothreonine / chemistry
Protein Interaction Domains and Motifs
Protein Multimerization
RNA Interference
RNA, Small Interfering / genetics
Recombinant Proteins / chemistry
Recombinant Proteins / genetics
Recombinant Proteins / metabolism
Sequence Homology, Amino Acid
Signal Transduction
Tumor Necrosis Factor-alpha / metabolism*

Substances

Adaptor Proteins, Signal Transducing
Antibodies, Monoclonal
Forkhead Transcription Factors
Mutant Proteins
NF-kappa B
RNA, Small Interfering
Recombinant Proteins
TIFA protein, human
Tumor Necrosis Factor-alpha
Phosphothreonine