Two fibrinogen-related proteins (FREPs) in the razor clam (Sinonovacula constricta) with a broad recognition spectrum and bacteria agglutination activity

Yinghan Wu; Yi Zheng; Yan Li; Yifeng Li; Donghong Niu

doi:10.1016/j.dci.2021.104075

Two fibrinogen-related proteins (FREPs) in the razor clam (Sinonovacula constricta) with a broad recognition spectrum and bacteria agglutination activity

Dev Comp Immunol. 2021 Aug:121:104075. doi: 10.1016/j.dci.2021.104075. Epub 2021 Mar 23.

Authors

Yinghan Wu¹, Yi Zheng¹, Yan Li¹, Yifeng Li², Donghong Niu³

Affiliations

¹ Key Laboratory of Exploration and Utilization of Aquatic Genetic Resources, Ministry of Education, Shanghai Ocean University, Shanghai, 201306, China.
² Key Laboratory of Exploration and Utilization of Aquatic Genetic Resources, Ministry of Education, Shanghai Ocean University, Shanghai, 201306, China; Shanghai Engineering Research Centre of Aquaculture, Shanghai, 201306, China.
³ Key Laboratory of Exploration and Utilization of Aquatic Genetic Resources, Ministry of Education, Shanghai Ocean University, Shanghai, 201306, China; Shanghai Engineering Research Centre of Aquaculture, Shanghai, 201306, China; Co-Innovation Center of Jiangsu Marine Bio-industry Technology, Jiangsu Ocean University, Lianyungang, 222005, China. Electronic address: dhniu@shou.edu.cn.

PMID: 33766584
DOI: 10.1016/j.dci.2021.104075

Abstract

Fibrinogen-related proteins (FREPs) that contain only the fibrinogen-related domain are likely involved in pathogen recognition. In this study, we identified two FREPs from the razor clam (Sinonovacula constricta), called ScFREP-1 and ScFREP-2, and investigated their roles in the immune response. Both ScFREP-1 and ScFREP-2 contained a fibrinogen-related domain at the C-terminal. ScFREP-1 and ScFREP-2 mRNAs were detected in all adult clam tissues tested, with the highest expression levels in the gill and mantle, respectively. Their expression levels were significantly upregulated after microbe infection. Recombinant ScFREPs could bind Gram-positive and Gram-negative bacteria as well as some pathogen-associated molecular patterns (PAMPs), and they could agglutinate those bacteria. These results showed that ScFREPs functioned as potential pattern recognition receptors to mediate immune response by recognizing PAMPs and agglutinating invasive microbes.

Keywords: Fibrinogen-related proteins; Innate immunity; Pattern recognition receptors; Sinonovacula constricta.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Agglutination / immunology
Animals
Bivalvia / genetics
Bivalvia / immunology*
Bivalvia / microbiology
Gills / immunology
Gills / metabolism
Gills / microbiology
Gram-Negative Bacteria
Gram-Positive Bacteria
Immunity, Innate*
Immunoglobulins / genetics
Immunoglobulins / metabolism*
Pathogen-Associated Molecular Pattern Molecules / metabolism
Phagocytosis
Phylogeny
Protein Domains / genetics
Receptors, Pattern Recognition / genetics
Receptors, Pattern Recognition / metabolism*
Recombinant Proteins / genetics
Recombinant Proteins / metabolism
Up-Regulation / immunology

Substances

Immunoglobulins
Pathogen-Associated Molecular Pattern Molecules
Receptors, Pattern Recognition
Recombinant Proteins