. "Edited: Garapati, P V, 2010-08-02"^^ . "Reviewed: Kawai, T, Akira, S, 2010-10-30"^^ . "Authored: Garapati, P V, 2010-08-02"^^ . "On viral infection RIG-I undergoes robust ubiquitination at its N-terminal CARD region. TRIM25 a member of tripartite motif (TRIM) protein family and Riplet/RNF135/REUL are the ubiquitin E3 ligases involved in K-63-linked polyubiquitination of RIG-I. TRIM25 contains a cluster of domains including a RING-finger domain, a B box/coiled-coil domain and a SPRY domain. The interaction is mediated by the SPRY domain of TRIM25 and the N-terminal CARDs of RIG-I. The polyubiquitin chains added by TRIM25 are unanchored Lys-172 (K-172) residue of RIG-I is critical for efficient TRIM25-mediated ubiquitination and for IPS-1 binding, as well as the ability of RIG-I to induce antiviral signal transduction. RING-finger protein, RNF135 specifically associate with RIG-I through its PRY and SPRY domains. The Lys 154, 164, and 172 residues of the RIG-I CARD domain were determined to be critical for efficient RNF135-mediated ubiquitination and for the ability of RIG-I to induce antiviral signal transduction. (Michaela et al, Goa et al)"^^ . . . . . . . . . "K-63-linked polyubiquitination of RIG-I"^^ . "6.3.2.19"^^ . . . . . . .