Eukaryotic elongation factor 2 is involved in the anticoccidial action of diclazuril in the second-generation merozoites of Eimeria tenella

• Published in: Veterinary parasitology Vol. 276; p. 108991
• Main Authors: Zhou, Bian-hua, Jia, Liu-shu, Guo, Hong-wei, Ding, Hai-yan, Yang, Jing-yun, Wang, Hong-wei
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 01.12.2019
• Subjects: Amino Acid Sequence; Animals; Base Sequence; Blotting, Western; Chickens - parasitology; Coccidiosis - drug therapy; Coccidiosis - parasitology; Coccidiosis - veterinary; Coccidiostats - pharmacology; Diclazuril; Eimeria tenella; Eimeria tenella - drug effects; Eimeria tenella - genetics; Elongation Factor 2 Kinase - genetics; Elongation Factor 2 Kinase - metabolism; Eukaryotic elongation factor 2; Female; Fluorescent Antibody Technique; Male; Merozoites - drug effects; Merozoites - genetics; Mice; Mice, Inbred BALB C; Nitriles - pharmacology; Phylogeny; Poultry Diseases - drug therapy; Poultry Diseases - parasitology; Real-Time Polymerase Chain Reaction; Second-generation merozoites; Sequence Alignment; Triazines - pharmacology; Eimeria tenella; Diclazuril; Second-generation merozoites; Eukaryotic elongation factor 2
• ISSN: 0304-4017; 1873-2550
• DOI: 10.1016/j.vetpar.2019.108991

•The full-length cDNA of EtEF2 of E. tenella were cloned and characterized.•EtEF2 displays high sequence homology with other eukaryotic organisms.•EtEF2 was characteristic with typical transaction related structure.•The localization of EtEF2 was primarily at the cytoplasm.•Diclazuril up-regulated the mRNA and protein expression levels of EtEF2. Eimeria tenella, an obligate intracellular parasite, can actively invade the cecal epithelial cells of chickens and cause severe enteric disease. Eukaryotic elongation factor 2 (eEF2) plays a major role in protein synthesis and cell survival. This study aims to explore the exact mechanisms underlying diclazuril inhibition in second-generation merozoites of E. tenella. The eEF2 cDNA of the second-generation merozoites of E. tenella (EtEF2) was cloned by reverse transcriptase polymerase chain reaction and rapid amplification of cDNA ends. Diclazuril-induced expression profiles of EtEF2 were also analyzed. The cloned full-length cDNA (2893 bp) of the EtEF2 nucleotide sequence encompassed a 2499 bp open reading frame (ORF) that encoded a polypeptide of 832 residues with an estimated molecular mass of 93.12 kDa and a theoretical isoelectric point of 5.99. The EtEF2 nucleotide sequence was submitted to the GenBank database with the accession number KF188423. The EtEF2 protein sequence shared 99 % homology with the eEF2 sequence of Toxoplasma gondii (GenBank XP_002367778.1). The GTPase activity domain and ADP-ribosylation domain were conserved signature sequences of the eEF2 gene family. The changes in the transcriptional and translational levels of EtEF2 were detected through quantitative real-time PCR and Western blot analyses. The mRNA expression level of EtEF2 was 2.706 fold increases and the protein level of EtEF2 was increased 67.31 % under diclazuril treatment. In addition, the localization of EtEF2 was investigated through immunofluorescence assay. Experimental results demonstrated that EtEF2 was distributed primarily in the cytoplasm of second-generation merozoites, and its fluorescence intensity was enhanced after diclazuril treatment. These findings indicated that EtEF2 may have an important role in understanding the signaling mechanism underlying the anticoccidial action of diclazuril and could be a promising target for novel drug exploration.