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Identification of Functional Protein Regions Through Chimeric Protein Construction
Published on: January 8, 2019
Molecular cloning and functional analysis of polymeric immunoglobulin receptor, pIgR, gene in mandarin fish Siniperca
Jia Xiang Ji1, Lin Zhang2, Li Li1
1State Key Laboratory of Freshwater Ecology and Biotechnology and Key Laboratory of Aquaculture Disease Control, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, Hubei Province, 430072, China.
Abstract:
Polymeric immunoglobulin receptor (pIgR) can bind and transport immunoglobulins (Igs), thus playing a role in mucosal immunity. In this study, pIgR gene was cloned in mandarin fish, Siniperca chuatsi, with the open reading frame (ORF) of 1011 bp, encoding 336 amino acids. The pIgR protein consists of a signal peptide, an extracellular domain, a transmembrane domain and an intracellular region, with the presence of two Ig-like domains (ILDs) in the extracellular domain, as reported in other species of fish. The pIgR gene was expressed in all organs/tissues of healthy mandarin fish, with higher level observed in liver and spleen. Following the immersion infection of Flavobacterium columnare, pIgR transcripts were detected in immune related, especially mucosal tissues, with significantly increased transcription during the first two days of infection. Through transfection of plasmids expressing pIgR, IgT and IgM, pIgR was found to be interacted with IgT and IgM as revealed by co-immunoprecipitation and immunofluorescence.

