Molecular cloning and characterization of a putative mitogen-activated protein kinase (Erk1/2) gene: Involvement in mantle immunity of Pinctada fucata

Hua Zhang; Zekui Ou; Meng Xu; Xiande Huang; Wenguang Liu; Yu Shi; Maoxian He

doi:10.1016/j.fsi.2018.05.047

Molecular cloning and characterization of a putative mitogen-activated protein kinase (Erk1/2) gene: Involvement in mantle immunity of Pinctada fucata

Fish Shellfish Immunol. 2018 Sep:80:63-70. doi: 10.1016/j.fsi.2018.05.047. Epub 2018 May 30.

Authors

Hua Zhang¹, Zekui Ou¹, Meng Xu¹, Xiande Huang², Wenguang Liu², Yu Shi², Maoxian He³

Affiliations

¹ CAS Key Laboratory of Tropical Marine Bio-resources and Ecology, Guangdong Provincial Key Laboratory of Applied Marine Biology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangdong, Guangzhou, 510301, China; University of Chinese Academy of Sciences, Beijing, 100049, China.
² CAS Key Laboratory of Tropical Marine Bio-resources and Ecology, Guangdong Provincial Key Laboratory of Applied Marine Biology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangdong, Guangzhou, 510301, China.
³ CAS Key Laboratory of Tropical Marine Bio-resources and Ecology, Guangdong Provincial Key Laboratory of Applied Marine Biology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangdong, Guangzhou, 510301, China. Electronic address: hmx2@scsio.ac.cn.

PMID: 29859309
DOI: 10.1016/j.fsi.2018.05.047

Abstract

Extracellular signal-regulated kinases (ERKs) are conserved and related with protein-serine/threonine kinases that participate in the regulation of multiple biological processes, such as cell survival, cell differentiation, proliferation, metabolism, and inflammation. However, little is known about the roles of this kinase in the pearl oyster. In this study, we cloned and identified an ERK homolog from Pinctada fucata (PfErk). Furthermore, we have unraveled its expressional kinetics after lipopolysaccharide (LPS) and polyinosinic-epolycytidylic acid (poly I:C) immune challenge. Pferk harbored a 5' untranslated region (UTR) of 12 bp, a coding sequence of 1074 bp, and a 3' UTR of 882 bp. The putative peptide comprised a predicted molecular mass of 41.19 kDa, with a theoretical pI of 6.15. Sequence analysis showed that it possesses one STK catalytic domain and a conserved His-Arg-Asp (HRD) domain. In addition, a canonical Thr-Glu-Tyr (TEY) dual phosphorylation motif and an ATRW substrate binding site were also identified in the coding protein. Homology assessment of PfErk showed high similarity to Homo sapiens ERK. Phylogenetic analysis supported a close evolutionary relationship with molluscan orthologs. The expression patterns of Pferk were observed in seven different tissues of pearl oyster, with highest expression in the mantle and lowest expression in the digestive gland. Pferk mRNA expression levels were detected at developmental stages, with the highest expression in D-shaped larvae, followed by the 32-cell stage. The mRNA expression of Pferk was upregulated significantly in P. fucata mantle primary cells and mantle tissue after LPS and poly (I:C) treatment, and PfErk phosphorylation levels were activated by LPS and poly (I:C) challenges. Overall, our results suggested that PfErk may play important roles in pearl oyster innate immunity, and provided a new understanding of mantle immunity in the pearl oyster.

Keywords: ERK; Expression patterns; Mantle immunity; Pinctada fucata.

MeSH terms

Amino Acid Sequence
Animals
Cells, Cultured
Cloning, Molecular
DNA, Complementary / genetics
Lipopolysaccharides / pharmacology
Mitogen-Activated Protein Kinases / genetics*
Mitogen-Activated Protein Kinases / immunology*
Open Reading Frames
Phylogeny
Pinctada / genetics*
Pinctada / immunology*
Poly I-C / pharmacology
RNA, Messenger / metabolism

Substances

DNA, Complementary
Lipopolysaccharides
RNA, Messenger
Mitogen-Activated Protein Kinases
Poly I-C