TNF Receptor Associated Factor 3 Interacting Protein 1 (TRAF3IP1)

The deduced 625-amino acid protein contains a KKE motif and a C-terminal coiled-coil domain. Northern blot analysis revealed expression of 4.4- and 2.4-kb transcripts in all tissues examined. Testis also expressed a 2.7-kb transcript.the interaction required the coiled-coil TRAF-N domain of TRAF3 and the C-terminal coiled-coil domain of MIPT3. When expressed separately, both MIPT3 and TRAF3 showed a cytosolic localization, but when coexpressed, both proteins colocalized with tubulin in cytoskeletal structures. MIPT3 bound to Taxol-stabilized microtubules and to tubulin in vitro, and MIPT3 recruited TRAF3 to microtubules when both proteins were overexpressed in HeLa cells. Mutation analysis of in vitro translated MIPT3 revealed that the tubulin-binding domain of MIPT3 resides within the N-terminal region.