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Hou L, Qiao X, Li Y, Jin Y, Liu R, Wang S, Zhou K, Wang L, Song L. A RAC-alpha serine/threonine-protein kinase (CgAKT1) involved in the synthesis of CgIFNLP in oyster Crassostrea gigas. FISH & SHELLFISH IMMUNOLOGY 2022; 127:129-139. [PMID: 35709896 DOI: 10.1016/j.fsi.2022.05.057] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/11/2022] [Revised: 05/28/2022] [Accepted: 05/30/2022] [Indexed: 06/15/2023]
Abstract
The RAC-alpha serine/threonine-protein kinase (AKT) is one of the most important protein kinases involved in many biological processes in eukaryotes. In the present study, a novel AKT homologue named CgAKT1 was identified from the Pacific oyster Crassostrea gigas. The open reading frame (ORF) of CgAKT1 cDNA was of 1482 bp encoding a peptide with 493 amino acid residues. There were classical domains in the predicted CgAKT1 protein, including an N-terminal pleckstrin homology domain, a central catalytic domain and a C-terminal hydrophobic domain. The mRNA transcripts of CgAKT1 were detected in all the examined tissues of C. gigas with higher level in gills (8.24-fold of that in mantle, p < 0.05) and haemocytes (3.62-fold of that in mantle, p < 0.05). After poly (I:C) stimulation, the mRNA expression of CgAKT1 decreased significantly in haemocytes from 3 h (0.44-fold of that in the control group, p < 0.001) to 24 h (0.20-fold of that in the control group, p < 0.001), and then increased significantly at 48 h (3.65-fold of that in the control group, p < 0.05). The expression level of CgAKT1 mRNA increased significantly at 6 h after rCgIFNLP stimulation, which was 3.60-fold of that in the control group (p < 0.001). The Alexa Fluor 488 positive signals of CgAKT1 protein were found to be distributed in the cytoplasm and cell membrane of haemocytes, while those in the cytoplasm became weaker after poly (I:C) stimulation. In CgAKT1-RNAi oysters, the mRNA expression of cyclic GMP-AMP synthase (CgcGAS) and TANK-binding kinase 1 (CgTBK1) did not change significantly, but the mRNA expression level of stimulator of interferon gene (CgSTING), interferon regulatory factor-1 (CgIRF-1), interferon regulatory factor-8 (CgIRF-8) and IFN-like protein (CgIFNLP) increased significantly, which was 1.40-fold, 1.53-fold, 1.72-fold and 1.99-fold of that in EGFP-RNAi oysters (p < 0.05), respectively. In CgIFNLP-RNAi oysters, the transcripts of CgAKT1 decreased significantly compared to those in EGFP-RNAi oysters (0.16-fold, p < 0.01). Moreover, the expression of p-CgTBK1, CgSTING and CgIFNLP at the protein level in the oysters treated with p-AKT1 activator (SC-79) was significantly suppressed after poly (I:C) stimulation. After the transfection of CgAKT1, the expression of p-cGAS protein in HEK293T cells increased significantly, while the cyclic GMP-AMP in the cells and the interferon (IFN-β) in the cell culture fluid decreased significantly compared with that in the control group. These results indicated that CgAKT1 might play a negative role in antiviral immunity of oyster by regulating the synthesis of CgIFNLP.
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Affiliation(s)
- Lilin Hou
- Liaoning Key Laboratory of Marine Animal Immunology, Dalian Ocean University, Dalian, 116023, China; Liaoning Key Laboratory of Marine Animal Immunology and Disease Control, Dalian Ocean University, Dalian, 116023, China; Dalian Key Laboratory of Aquatic Animal Disease Prevention and Control, Dalian Ocean University, Dalian, 116023, China
| | - Xue Qiao
- Liaoning Key Laboratory of Marine Animal Immunology, Dalian Ocean University, Dalian, 116023, China; Liaoning Key Laboratory of Marine Animal Immunology and Disease Control, Dalian Ocean University, Dalian, 116023, China; Dalian Key Laboratory of Aquatic Animal Disease Prevention and Control, Dalian Ocean University, Dalian, 116023, China
| | - Youjing Li
- Liaoning Key Laboratory of Marine Animal Immunology, Dalian Ocean University, Dalian, 116023, China; Liaoning Key Laboratory of Marine Animal Immunology and Disease Control, Dalian Ocean University, Dalian, 116023, China; Dalian Key Laboratory of Aquatic Animal Disease Prevention and Control, Dalian Ocean University, Dalian, 116023, China
| | - Yuhao Jin
- Liaoning Key Laboratory of Marine Animal Immunology, Dalian Ocean University, Dalian, 116023, China; Liaoning Key Laboratory of Marine Animal Immunology and Disease Control, Dalian Ocean University, Dalian, 116023, China; Dalian Key Laboratory of Aquatic Animal Disease Prevention and Control, Dalian Ocean University, Dalian, 116023, China
| | - Ranyang Liu
- Liaoning Key Laboratory of Marine Animal Immunology, Dalian Ocean University, Dalian, 116023, China; Liaoning Key Laboratory of Marine Animal Immunology and Disease Control, Dalian Ocean University, Dalian, 116023, China; Dalian Key Laboratory of Aquatic Animal Disease Prevention and Control, Dalian Ocean University, Dalian, 116023, China
| | - Sicong Wang
- Liaoning Key Laboratory of Marine Animal Immunology, Dalian Ocean University, Dalian, 116023, China; Liaoning Key Laboratory of Marine Animal Immunology and Disease Control, Dalian Ocean University, Dalian, 116023, China; Dalian Key Laboratory of Aquatic Animal Disease Prevention and Control, Dalian Ocean University, Dalian, 116023, China
| | - Kai Zhou
- Liaoning Key Laboratory of Marine Animal Immunology, Dalian Ocean University, Dalian, 116023, China; Liaoning Key Laboratory of Marine Animal Immunology and Disease Control, Dalian Ocean University, Dalian, 116023, China; Dalian Key Laboratory of Aquatic Animal Disease Prevention and Control, Dalian Ocean University, Dalian, 116023, China
| | - Lingling Wang
- Liaoning Key Laboratory of Marine Animal Immunology, Dalian Ocean University, Dalian, 116023, China; Functional Laboratory of Marine Fisheries Science and Food Production Processes, Qingdao National Laboratory for Marine Science and Technology, Qingdao, 266235, China; Liaoning Key Laboratory of Marine Animal Immunology and Disease Control, Dalian Ocean University, Dalian, 116023, China; Dalian Key Laboratory of Aquatic Animal Disease Prevention and Control, Dalian Ocean University, Dalian, 116023, China
| | - Linsheng Song
- Liaoning Key Laboratory of Marine Animal Immunology, Dalian Ocean University, Dalian, 116023, China; Functional Laboratory of Marine Fisheries Science and Food Production Processes, Qingdao National Laboratory for Marine Science and Technology, Qingdao, 266235, China; Liaoning Key Laboratory of Marine Animal Immunology and Disease Control, Dalian Ocean University, Dalian, 116023, China; Dalian Key Laboratory of Aquatic Animal Disease Prevention and Control, Dalian Ocean University, Dalian, 116023, China.
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