LAUSR

ABSTRACT The receptor for activated C kinase 1 (RACK1) is a intracellular receptor for the protein kinase C family which mediates various biological processes. Here, a novel RACK1 gene termed Mc‐RACK1 was identified from thick shell mussel, Mytilus coruscus. Mc‐RACK1 shared typical RACK1 domains containing WD repeats, PKC phosphorylation sites, N‐myristoylation sites, PKC activation sites, TK phosphorylation site and WD motifs. Mc‐RACK1 was constitutively expressed in all examined tissues, and its expression in gills, haemocytes and digestive glands were significantly up‐regulated upon LPS challenge. Mc‐RACK1 showed a significantly down‐regulated expression in gills and haemocytes at the early phase upon copper exposure. Mc‐RACK1 in haemocytes was silenced after receiving its dsRNA, meanwhile, the increases of SOD and CAT activity were investigated. Further, Mc‐RACK1 could activate the NF‐&kgr;B and ISRE reporter in HEK‐293T cells. These suggested that Mc‐RACK1 had a deeper involvement in mollusc immunity, and played an important role in antioxidant system. HighlightsA novel RACK1 gene was firstly identified from Mytilus coruscus.Mc‐RACK1 expression were significantly up‐regulated upon LPS challenge.Mc‐RACK1 expression were down‐regulated at the early phase upon copper exposure.The enhanced activities of SOD and CAT in haemocytes received Mc‐RACK1 dsRNA.Mc‐RACK1 could activate the NF‐&kgr;B and ISRE reporter in HEK‐293T cells.