TRAF-interacting protein with a forkhead-associated domain B (TIFAB) is a negative regulator of the TRAF6-induced cellular functions.

Abstract

Tumour necrosis factor receptor-associated factor (TRAF)-interacting protein with a forkhead-associated domain (TIFA) activates TRAF6 to induce NF-kappaB activation. TIFA-related protein, TIFAB, is highly expressed in the spleen and inhibits TIFA-mediated TRAF6 activation. However, little is known about cell types that express TIFAB and its function in those cells. Here, we show that TIFAB is mainly expressed in B cells rather than T cells in the spleen and that the expression level was much higher in dendritic cells (DCs) and macrophages than that in splenic lymphocytes. TIFAB expression was downregulated when B cells, DCs or macrophages were stimulated by TRAF6-mediated proliferative or maturation signals including those emanating from CD40, sIgM and TLRs. Furthermore, microinjection experiments using NIH3T3 cells revealed that TIFAB inhibited entry into the S phase of the cell cycle. Our results suggest that TIFAB could act as a negative regulator of the TRAF6-induced cellular function such as B cell proliferation and maturation of DCs and macrophages.

• Authors: Takayuki Matsumura, Junko Kawamura-Tsuzuku, Tadashi Yamamoto, Kentaro Semba, Jun-Ichiro Inoue
• Journal: Journal of biochemistry (J Biochem) Vol. 146 Issue 3 Pg. 375-81 (Sep 2009) ISSN: 1756-2651 [Electronic] England
• PMID: 19470519 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Antibodies, Anti-Idiotypic
• Intracellular Signaling Peptides and Proteins
• Lipopolysaccharides
• Proteins
• RNA, Messenger
• TIFAB protein, mouse
• TNF Receptor-Associated Factor 6
• Toll-Like Receptor 7
• Toll-Like Receptor 9
• anti-IgM
• lipopolysaccharide, Escherichia coli O111 B4
• CD40 Ligand

Topics

• Animals
• Antibodies, Anti-Idiotypic
• B-Lymphocytes (metabolism)
• Bone Marrow Cells
• CD40 Ligand (metabolism)
• Cell Cycle
• Cells, Cultured
• Dendritic Cells (metabolism)
• Down-Regulation
• Intracellular Signaling Peptides and Proteins
• Lipopolysaccharides
• Macrophages (metabolism)
• Mice
• Mice, Inbred C57BL
• Microinjections
• NIH 3T3 Cells
• Plasmids
• Proteins (chemistry, metabolism)
• RNA, Messenger (metabolism)
• Spleen (cytology, metabolism)
• T-Lymphocytes (metabolism)
• TNF Receptor-Associated Factor 6 (metabolism)
• Toll-Like Receptor 7 (agonists)
• Toll-Like Receptor 9 (agonists)