A novel JNK induces innate immune response by activating the expression of antimicrobial peptides in Chinese mitten crab Eriocheir sinensis. (October 2021)

• Record Type: Journal Article
• Authors: Huang, Ying; Nie, Xi-mei; Zhu, Zheng-jie; Zhang, Xing; Li, Bing-zhi; Ge, Jia-chun; Ren, Qian
• Is Part Of: Molecular immunology. Volume 138(2021)
• Page Start: 76
• Page End: 86
• Publication Date: 2021-10
• Subjects: c-Jun NH2-terminal kinase -- Antimicrobial peptides -- Antibacterial response -- Innate immunity -- Eriocheir sinensis; Immunochemistry -- Periodicals; Molecular biology -- Periodicals; Immunochemistry -- Periodicals; Allergy and Immunology -- Periodicals; Molecular Biology -- Periodicals; Immunochimie -- Périodiques; Biologie moléculaire -- Périodiques; Immunochemistry; Molecular biology; Periodicals; Electronic journals; 571.96
• DOI: 10.1016/j.molimm.2021.07.011
• Languages: English
• ISSNs: 0161-5890

Abstract

Highlights: A JNK and its isoform were identified from Eriocheir sinensis . Bacteria challenge upregulated the expression of EsJNK . RNAi showed that EsJNK regulated the transcription of two AMPs . Knockdown of EsJNK can weaken the host's ability to eliminate bacteria. rEsJNK protein can accelerate the bacterial clearance. Abstract: c-Jun NH2 -terminal kinase (JNK) is a member of mitogen-activated protein kinases (MAPKs) that participates in the regulation of various physiological and pathological processes. In this study, we identified a novel JNK ( EsJNK ) and determined the cDNA sequence of its isoform ( EsJNK-a ) from the Chinese mitten crab Eriocheir sinensis . The open reading frame (ORF) of EsJNK was predicted to encode 421 peptides with a serine/threonine protein kinase, a catalytic (S_TKc) domain, and a low complexity region. The ORF of EsJNK-a was 1380 bp encoding a protein with 459 amino acids, which was 38 amino acids more than that of EsJNK. The predicted tertiary structure of EsJNK was conserved and contained 15 α-helices and 10 β-sheets. Phylogenetic tree analysis revealed that EsJNK was clustered with the JNK homologs of other crustaceans. Quantitative real-time PCR assays showed that EsJNK was expressed in all the tissues examined, but it was relatively higher in hemocytes, muscles, and intestines. The expression of EsJNK mRNA in the hemocytes was upregulated by lipopolysaccharides and peptidoglycans, as well as by Staphylococcus aureus or Vibrio parahaemolyticus challenge. Functionally, after silencing EsJNK by siRNA in crabs, the expression levels of two antimicrobial peptides (AMPs), namely, anti-lipopolysaccharide factor and crustin, were significantly inhibited. The purified recombinant EsJNK protein with His-tag accelerated the elimination of the aforementioned bacteria in vivo . However, knockdown of EsJNK had an opposite effect. These findings suggested that EsJNK might be involved in the antibacterial immune defense of crabs by regulating the transcription of AMPs.