1
|
Wang J, Hu H, Pang S, Yin X, Cao B, Huang J, Xu X, Weng Q, Hu Q. Destruxin A inhibits the hemocytin-mediated hemolymph immunity of host insects to facilitate Metarhizium infection. Cell Rep 2024; 43:113686. [PMID: 38219149 DOI: 10.1016/j.celrep.2024.113686] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2023] [Revised: 11/07/2023] [Accepted: 01/02/2024] [Indexed: 01/16/2024] Open
Abstract
Insects have an effective innate immune system to protect themselves against fungal invasion. Metarhizium employs a toxin-based strategy using a nonribosomal peptide called destruxin A (DA) to counteract the host immune response. However, the mechanism by which DA inhibits insect immunity is still unclear. Here, we identified 48 DA-binding proteins in silkworm hemolymph, with the binding affinity (KD) ranging from 2 to 420 μM. Among these proteins, hemocytin, an important immune factor, was determined to be the strongest DA-binding protein. DA binds to hemocytin and regulates its conformation in a multisite manner. Furthermore, DA exerts a significant inhibitory effect on hemocytin-mediated hemocyte aggregation. By disrupting the interaction between hemocytin, actin A3, and gelsolin, DA prevents the transformation of granules into vesicles in hemocytes. These vesicles are responsible for storing, maturing, and exocytosing hemocytin. Therefore, hemocytin secretion is reduced, and the formation of structures that promote aggregation in outer hemocytes is inhibited.
Collapse
Affiliation(s)
- Jingjing Wang
- College of Plant Protection, South China Agricultural University, Wushan RD483, Tianhe, Guangzhou, China; College of Horticulture, South China Agricultural University, Wushan RD483, Tianhe, Guangzhou, China
| | - Hongwang Hu
- College of Plant Protection, South China Agricultural University, Wushan RD483, Tianhe, Guangzhou, China
| | - Suyun Pang
- College of Plant Protection, South China Agricultural University, Wushan RD483, Tianhe, Guangzhou, China
| | - Xuyu Yin
- College of Plant Protection, South China Agricultural University, Wushan RD483, Tianhe, Guangzhou, China
| | - Bihao Cao
- College of Horticulture, South China Agricultural University, Wushan RD483, Tianhe, Guangzhou, China
| | - Jilei Huang
- Instrumental Analytical and Research Center, South China Agricultural University, Wushan RD483, Tianhe, Guangzhou, China
| | - Xiaoli Xu
- Instrumental Analytical and Research Center, South China Agricultural University, Wushan RD483, Tianhe, Guangzhou, China
| | - Qunfang Weng
- College of Plant Protection, South China Agricultural University, Wushan RD483, Tianhe, Guangzhou, China
| | - Qiongbo Hu
- College of Plant Protection, South China Agricultural University, Wushan RD483, Tianhe, Guangzhou, China.
| |
Collapse
|
2
|
Tan T, Liu R, Luo Q, Ma J, Ou Y, Zeng W, Feng L, Xu H. The intronic promoter of Actin4 mediates high-level transgene expression mainly in the wing and epidermis of silkworms. Transgenic Res 2020; 29:243-251. [PMID: 31960249 DOI: 10.1007/s11248-020-00192-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2019] [Accepted: 01/16/2020] [Indexed: 11/24/2022]
Abstract
The cytoplasmic actin gene Actin4 (A4) in silkworm (Bombyx mori) was isolated 20 years ago and has a distal promoter upstream of the first exon and a proximal promoter within the first intron; however, how the promoter regulates gene expression has yet to be fully elucidated. Here, we characterized the function and expression of the proximal promoter (named A4IP) by analyzing transgenic Gal4/UAS silkworms, A4IP-Gal4/UAS-EGFP. We demonstrated that A4IP drives the expression of Gal4 and thereby activates UAS-linked EGFP in transgenic silkworms beginning in day-3 embryos through adults. Further detection revealed that EGFP was expressed at a low level in tissues including the trachea, fat body and midgut but was highly expressed in the wing disks/wings and inner epidermis of transgenic silkworms. No EGFP signals were detected in other tissues by western blot assay. Interestingly, EGFP fluorescence had a spot-like distribution on the epidermis of transgenic larvae. These observations are quite different from those in transgenic silkworms driven by the promoter of Actin3 (A3), another cytoplasmic actin gene in B. mori. These findings reveal the expression profiles of the A4IP promoter and provide new insights into the regulatory mechanism of cytoplasmic actin genes in silkworms.
Collapse
Affiliation(s)
- Tingting Tan
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, China
- College of Biotechnology, Southwest University, Chongqing, China
| | - Rongpeng Liu
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, China
| | - Qin Luo
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, China
| | - Jingwen Ma
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, China
- College of Biotechnology, Southwest University, Chongqing, China
| | - Yao Ou
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, China
| | - Wenhui Zeng
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, China
| | - Lichun Feng
- College of Biotechnology, Southwest University, Chongqing, China
| | - Hanfu Xu
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, China.
- College of Biotechnology, Southwest University, Chongqing, China.
| |
Collapse
|
3
|
Lü P, Xing Y, Hu Z, Yang Y, Pan Y, Chen K, Zhu F, Zhou Y, Chen K, Yao Q. A characterization of structural proteins expressed by Bombyx mori bidensovirus. J Invertebr Pathol 2017; 144:18-23. [DOI: 10.1016/j.jip.2016.12.008] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2016] [Revised: 12/23/2016] [Accepted: 12/30/2016] [Indexed: 10/20/2022]
|
4
|
Jiang L, Peng Z, Guo Y, Cheng T, Guo H, Sun Q, Huang C, Zhao P, Xia Q. Transcriptome analysis of interactions between silkworm and cytoplasmic polyhedrosis virus. Sci Rep 2016; 6:24894. [PMID: 27118345 PMCID: PMC4847007 DOI: 10.1038/srep24894] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2015] [Accepted: 04/06/2016] [Indexed: 01/22/2023] Open
Abstract
Bombyx mori cytoplasmic polyhedrosis virus (BmCPV) specifically infects silkworm midgut (MG) and multiplication occurs mainly in posterior midgut (PM). In this study, MG and fat body (FB) were extracted at 0, 3, 24, and 72 h after BmCPV infection. The total sequence reads of each sample were more than 1510000, and the mapping ratio exceeded 95.3%. Upregulated transcripts increased in MG during the infection process. Gene ontology (GO) categories showed that antioxidants were all upregulated in FB but not in MG. BGI001299, BGI014434, BGI012068, and BGI009201 were MG-specific genes with transmembrane transport function, the expression of which were induced by BmCPV. BGI001299, BGI014434, and BGI012068 expressed in entire MG and may be involved in BmCPV invasion. BGI009201 expressed only in PM and may be necessary for BmCPV proliferation. BmPGRP-S2 and BGI012452 (a putative serine protease) were induced by BmCPV and may be involved in immune defense against BmCPV. The expression level of BmCPV S1, S2, S3, S6, and S7 was high and there was no expression of S9 in MG 72 h, implying that the expression time of structural protein coding genes is earlier. These results provide insights into the mechanism of BmCPV infection and host defense.
Collapse
Affiliation(s)
- Liang Jiang
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing 400715, P. R. China
| | - Zhengwen Peng
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing 400715, P. R. China
| | - Youbing Guo
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing 400715, P. R. China
| | - Tingcai Cheng
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing 400715, P. R. China
| | - Huizhen Guo
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing 400715, P. R. China
| | - Qiang Sun
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing 400715, P. R. China
| | - Chunlin Huang
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing 400715, P. R. China
| | - Ping Zhao
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing 400715, P. R. China
| | - Qingyou Xia
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing 400715, P. R. China
| |
Collapse
|
5
|
Dong XL, Liu TH, Wang W, Pan CX, Wu YF, Du GY, Chen P, Lu C, Pan MH. BmREEPa Is a Novel Gene that Facilitates BmNPV Entry into Silkworm Cells. PLoS One 2015; 10:e0144575. [PMID: 26656276 PMCID: PMC4681539 DOI: 10.1371/journal.pone.0144575] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2015] [Accepted: 11/22/2015] [Indexed: 11/26/2022] Open
Abstract
We previously established two silkworm cell lines, BmN-SWU1 and BmN-SWU2, from Bombyx mori ovaries. BmN-SWU1 cells are susceptible while BmN-SWU2 cells are highly resistant to BmNPV infection. Interestingly, we found that the entry of BmNPV into BmN-SWU2 cells was largely inhibited. To explore the mechanism of this inhibition, in this study we used isobaric tags for relative and absolute quantitation (iTRAQ)-based quantitative protein expression profiling and identified 629 differentially expressed proteins between the two cell lines. Among them, we identified a new membrane protein termed BmREEPa. The gene encoding BmREEPa transcribes two splice variants; a 573 bp long BmREEPa-L encoding a protein with 190 amino acids and a 501 bp long BmREEPa-S encoding a protein with 166 amino acids. BmREEPa contains a conserved TB2/DP, HVA22 domain and three transmembrane domains. It is localized in the plasma membrane with a cytoplasmic C-terminus and an extracellular N-terminus. We found that limiting the expression of BmREEPa in BmN-SWU1 cells inhibited BmNPV entry, whereas over-expression of BmREEPa in BmN-SWU2 cells promoted BmNPV entry. Our results also indicated that BmREEPa can interact with GP64, which is the key envelope fusion protein for BmNPV entry. Taken together, the findings of our study revealed that BmREEPa is required for BmNPV to gain entry into silkworm cells, and may provide insights for the identification of BmNPV receptors.
Collapse
Affiliation(s)
- Xiao-long Dong
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, China
- Key Laboratory for Sericulture Functional Genomics and Biotechnology of Agricultural Ministry, Southwest University, Chongqing, China
| | - Tai-hang Liu
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, China
| | - Wei Wang
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, China
| | - Cai-xia Pan
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, China
| | - Yun-fei Wu
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, China
| | - Guo-yu Du
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, China
| | - Peng Chen
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, China
| | - Cheng Lu
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, China
- Key Laboratory for Sericulture Functional Genomics and Biotechnology of Agricultural Ministry, Southwest University, Chongqing, China
- * E-mail: (M-HP); (CL)
| | - Min-hui Pan
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, China
- Key Laboratory for Sericulture Functional Genomics and Biotechnology of Agricultural Ministry, Southwest University, Chongqing, China
- * E-mail: (M-HP); (CL)
| |
Collapse
|