A DM9-containing protein from oyster Crassostrea gigas (CgDM9CP-3) mediating immune recognition and encapsulation. (March 2021)

• Record Type: Journal Article
• Authors: Liu, Yu; Wang, Weilin; Zhao, Qi; Yuan, Pei; Li, Jiaxin; Song, Xiaorui; Liu, Zhaoqun; Ding, Dewen; Wang, Lingling; Song, Linsheng
• Is Part Of: Developmental and comparative immunology. Volume 116(2021)
• Publication Date: 2021-03
• Subjects: Crassostrea gigas -- DM9 domain -- Pathogen recognition -- Encapsulation; Immunology -- Periodicals; Developmental immunology -- Periodicals; 616.079
• DOI: 10.1016/j.dci.2020.103937
• Languages: English
• ISSNs: 0145-305X

Abstract

Abstract: DM9 domain containing protein (DM9CP) is a recently identified pattern recognition molecules exiting in most organisms except plants. In the present study, a novel DM9-containing protein ( Cg DM9CP-3) was identified from Pacific oyster Crassostrea gigas with an open reading frame of 438 bp, encoding a polypeptide of 145 amino acids containing two tandem DM9 repeats. The deduced amino acid sequence of Cg DM9CP-3 shared 52.4% and 58.6% identity with Cg DM9CP-1 and Cg DM9CP-2, respectively. The mRNA transcripts of Cg DM9CP-3 were highest expressed in oyster gills and its protein was mainly distributed in cytomembrane of haemocytes. After the stimulations with Vibrio splendidus and mannose, the mRNA expression of Cg DM9CP-3 in oyster gills was significantly up-regulated and reached the peak level at 12 h and 24 h ( p < 0.05), which was 7.80-fold ( p < 0.05) and 42.82-fold ( p < 0.05) of that in the control group, respectively. The recombinant Cg DM9CP-3 protein (r Cg DM9CP-3) was able to bind LPS, PGN and d -Mannose, fungi Pichia pastoris and Yarrowia lipolytica, as well as gram-negative bacteria Escherichia coli, Vibrio anguillarum and V. splendidus in a Ca 2+ -dependent manner. Moreover, it could enhance the encapsulation of haemocytes and exhibited agglutination activity towards fungi P. pastoris and Y. lipolytica in vitro with Ca 2+ . These results suggested that Cg DM9CP-3 not only acted as a PRR involved in the pathogen recognition, but also enhanced cellular encapsulation in oyster C. gigas . Highlights: A novel DM9-containing protein ( Cg DM9CP-3) was identified from Crassostrea gigas. The mRNA expression of Cg DM9CP-3 mRNA in gills was up-regulated after the stimulation with mannose or V. splendidus. r Cg DM9CP-3 exhibited significant activities to bind and aggregate fungi and Gram-negative bacteria. r Cg DM9CP-3 was able to enhance the encapsulation activity of haemocytes.