Apextrin from Ruditapes philippinarum functions as pattern recognition receptor and modulates NF-κB pathway
Kunyin Jiang1, Hongtao Nie2, Zhihui Yin2
1College of Fisheries and Life Science, Dalian Ocean University, 116023 Dalian, China; Engineering Research Center of Shellfish Culture and Breeding in Liaoning Province, Dalian Ocean University, 116023 Dalian, China; Key Laboratory of Mariculture, Ministry of Education, Ocean University of China, Qingdao 266003, China.
International Journal of Biological Macromolecules
|June 13, 2022
Summary
A new study identifies apextrin (Rpape) in the clam Ruditapes philippinarum, revealing its role in innate immunity. Rpape protein effectively combats bacterial infections and activates key immune signaling pathways.
Area of Science:
- Marine Biology
- Immunology
- Biochemistry
Background:
- Apextrin, a type of ApeC-containing protein (ACP), possesses a signal peptide, a MACPF domain, and an ApeC domain.
- Apextrin-like proteins function as pattern recognition receptors (PRRs) in innate immunity, detecting bacterial cell wall components.
Purpose of the Study:
- To identify and characterize apextrin in the clam Ruditapes philippinarum (Rpape).
- To investigate the immune role of Rpape against bacterial challenges.
Main Methods:
- Identification and mRNA expression analysis of Rpape under bacterial challenge.
- Recombinant Rpape protein expression and functional assays.
- Bacterial binding assays and analysis of immune signaling pathways (NF-κB, Nitric Oxide).
Main Results:
- Rpape mRNA levels significantly increased following bacterial exposure.
- Recombinant Rpape protein demonstrated significant inhibition against Gram-positive bacteria (Bacillus subtilis, Staphylococcus aureus).
- Rpape protein bound to Vibrio anguillarum, S. aureus, and B. subtilis, activating NF-κB signaling and increasing nitric oxide production.
Conclusions:
- Rpape plays a crucial role in the innate immune defense of Ruditapes philippinarum against bacterial infections.
- This study provides valuable insights into the function of apextrin in bivalve immunity.
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