Tumor necrosis factor (TNF) receptor associated factor 3 (TRAF3) is a highly versatile regulator that positively controls type I interferon production, but negatively regulates mitogen-activated protein (MAP) kinase activation and non-canonical nuclear factor-kB signalling []. It is a critical regulator of both innate and adaptive immune responses []. TRAF3 plays a role in the regulation of B-cell survival [], in the regulation of antiviral responses [], and in T-cell dependent immune responses []. It is required for normal antibody isotype switching from IgM to IgG []. Differences in the ubiquitination of TRAF3 are the key to the selective production of type I interferons versus proinflammatory cytokines [].
Tumor necrosis factor (TNF) receptor associated factor 3 (TRAF3) is a highly versatile regulator that positively controls type I interferon production, but negatively regulates mitogen-activated protein (MAP) kinase activation and non-canonical nuclear factor-kB signalling []. It is a critical regulator of both innate and adaptive immune responses []. TRAF3 plays a role in the regulation of B-cell survival [], in the regulation of antiviral responses [], and in T-cell dependent immune responses []. It is required for normal antibody isotype switching from IgM to IgG []. Differences in the ubiquitination of TRAF3 are the key to the selective production of type I interferons versus proinflammatory cytokines [].TRAF3 contains a RING finger domain, five zinc finger domains, and a TRAF domain. The TRAF domain can be divided into a more divergent N-terminal alpha helical region (TRAF-N), and a highly conserved C-terminal MATH subdomain (TRAF-C) with an eight-stranded β-sandwich structure. TRAF-N mediates trimerization while TRAF-C interacts with receptors [].
TRAF3IP1, also known as MIP-T3, which interacts with both microtubules and TRAF3 (tumour necrosis factor receptor-associated factor 3), is conserved from worms to humans. The N-terminal region is the microtubule binding domain and is well-conserved; the C-terminal 100 residues, also well-conserved, constitute the coiled-coil region which binds to TRAF3. The central region of the protein is rich in lysine and glutamic acid and carries KKE motifs which may also be necessary for tubulin-binding, but this region is the least well-conserved [].
TRAF3-interacting protein 1 (TRAF3IP1) recruits TRAF3 (tumour necrosis factor receptor-associated factor 3) and DISC1 (Disrupted-In-Schizophrenia 1) to the microtubules and is conserved from worms to humans []. The N-terminal region is the microtubule binding domain and is well-conserved; the C-terminal 100 residues, also well-conserved, constitute the coiled-coil region which binds to TRAF3. The central region of the protein is rich in lysine and glutamic acid and carries KKE motifs which may also be necessary for tubulin-binding, but this region is the least well-conserved []. In humans, it plays an inhibitory role on IL13 signaling by binding to IL13RA1. It is involved in suppression of IL13-induced STAT6 phosphorylation, transcriptional activity and DNA-binding [, ].
TRAF3-interacting protein 1 (TRAF3IP1) recruits TRAF3 (tumour necrosis factor receptor-associated factor 3) and DISC1 (Disrupted-In-Schizophrenia 1) to the microtubules and is conserved from worms to humans []. The N-terminal region is the microtubule binding domain and is well-conserved; the C-terminal 100 residues, also well-conserved, constitute the coiled-coil region which binds to TRAF3. The central region of the protein is rich in lysine and glutamic acid and carries KKE motifs which may also be necessary for tubulin-binding, but this region is the least well-conserved []. In humans, it plays an inhibitory role on IL13 signaling by binding to IL13RA1. It is involved in suppression of IL13-induced STAT6 phosphorylation, transcriptional activity and DNA-binding [, ].This superfamily represents the N-terminal domain of TRAF3-interacting protein 1.
TRAF3-interacting protein 1 (TRAF3IP1) recruits TRAF3 (tumour necrosis factor receptor-associated factor 3) and DISC1 (Disrupted-In-Schizophrenia 1) to the microtubules and is conserved from worms to humans []. The N-terminal region is the microtubule binding domain and is well-conserved; the C-terminal 100 residues, also well-conserved, constitute the coiled-coil region which binds to TRAF3. The central region of the protein is rich in lysine and glutamic acid and carries KKE motifs which may also be necessary for tubulin-binding, but this region is the least well-conserved []. In humans, it plays an inhibitory role on IL13 signaling by binding to IL13RA1. It is involved in suppression of IL13-induced STAT6 phosphorylation, transcriptional activity and DNA-binding [, ].This entry represents the N-terminal domain of TRAF3-interacting protein 1.
This entry includes the C2HC RNF-type zinc finger.Ubiquitination is a post-translational modification that mediates the covalent attachment of ubiquitin (Ub), a small, highly conserved, cytoplasmic protein of 76 amino acid residues, to target proteins. This conjugation is catalyzed by the sequential action of three enzymes: Ub-activating (E1) enzyme, Ub-conjugating (E2) enzyme and Ub ligase (E3). A large number of RING finger (RNF) proteins are present in eukaryotic cells and the majority of them are believed to act as E3 ubiquitin ligases. The closely related proteins RNF125/TRAC-1, RNF114 (also known as Zpf313), RNF138 (or NARF) and RNF166 contain, apart from the RING domain, a C2HC (Cys2-His-Cys)- and two C2H2 (Cys2-His2)-type zinc fingers, as well as an ubiquitin interacting motif (UIM) [, , , ].Some proteins known to contain a C2HC RNF-type zinc finger are listed below:Mammalian RNF125/T-cell RING protein in activation 1 (TRAC-1)/, a positive regulator of T-cell activation. It negatively regulates RIG-1 mediated antiviral activity via conjugating ubiquitin chains to RIG-1 and MDA5, leading to their degradation by the proteasome.Vertebrate RNF114, acts as negative regulator of NF-kappaB-dependent transcription. It interacts with A20 in T cells and modulates A20 ubiquitylation.Vertebrate RNF138, likely involved in regulating homologous recombination repair pathway.Vertebrate RNF166, potentiates the RNA virus-induced production of IFN-beta via enhancing the ubiquitination of TRAF3 and TRAF6.
