Scallop RIG-I-like receptor 1 responses to polyinosinic:polycytidylic acid challenge and its interactions with the mitochondrial antiviral signaling protein

Analysis of the presence of anti-viral innate immune pathways in the Australian Haliotis laevigata

“…Our analysis of the abalone genomes also revealed a lack of the essential adaptor protein MAVS, which interacts directly with RIG-I in the canonical pathways allowing for activation of downstream interferon regulatory factors. Within the molluscan family, both the oyster ( C. gigas ) and the scallop ( Chlamys farreri ) have been shown to encode a single MAVS homolog that reflects an unusual structure through the presence of a DEATH domain rather than a proline-rich domain; suggesting this particular counterpart may also bind alternate signalling activation factors to the canonically described ones in its role in downstream signalling [ 40 , 50 ]. Additionally, the C. gigas RLR pathway components have been demonstrated recently to be functional in the context of RIG-I being able to bind the synthetic dsRNA analog, poly I:C, and the downstream effectors including MAVS being required for activation of this RLR sensing pathway [ 40 ]; in the context of the scallop, MAVS has been shown to directly bind RIG-I [ 50 ].…”

“…Within the molluscan family, both the oyster ( C. gigas ) and the scallop ( Chlamys farreri ) have been shown to encode a single MAVS homolog that reflects an unusual structure through the presence of a DEATH domain rather than a proline-rich domain; suggesting this particular counterpart may also bind alternate signalling activation factors to the canonically described ones in its role in downstream signalling [ 40 , 50 ]. Additionally, the C. gigas RLR pathway components have been demonstrated recently to be functional in the context of RIG-I being able to bind the synthetic dsRNA analog, poly I:C, and the downstream effectors including MAVS being required for activation of this RLR sensing pathway [ 40 ]; in the context of the scallop, MAVS has been shown to directly bind RIG-I [ 50 ]. Interestingly, a functional RIG-I homolog in the freshwater planarian, Dugesia japonica, has recently been demonstrated to contain no CARD domains (required for an interaction with MAVS), and it does not encode for a classical MAVS; despite this, its RIG-I is able to bind poly I:C, and activate a downstream response pathway to induce a classical anti-viral signature [ 51 ].…”