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Zhang Y, Lu M, Huang J, Tian X, Liang M, Wang M, Song X, Xu L, Yan R, Li X. Identification and characterization of the receptors of a microneme adhesive repeat domain of Eimeria maxima microneme protein 3 in chicken intestine epithelial cells. Poult Sci 2024; 103:103486. [PMID: 38350385 PMCID: PMC10874745 DOI: 10.1016/j.psj.2024.103486] [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: 10/23/2023] [Revised: 01/03/2024] [Accepted: 01/17/2024] [Indexed: 02/15/2024] Open
Abstract
Eimeria maxima microneme protein 3 (EmMIC3) is pivotal in the initial recognition and attachment of E. maxima sporozoites to host cells. EmMIC3 comprises 5 tandem Type I microneme adhesive repeat (MAR) domains, among which MAR2 of EmMIC3 (EmMAR2) has been identified as the primary determinant of EmMIC3-mediated tissue tropism. Nonetheless, the mechanisms through which EmMAR2 guides the parasite to its invasion site through interactions with host receptors remained largely uncharted. In this study, we employed yeast two-hybrid (YTH) screening assays and shotgun LC-MS/MS analysis to identify EmMAR2 receptors in chicken intestine epithelial cells. ATPase H+ transporting V1 subunit G1 (ATP6V1G1), receptor accessory protein 5 (REEP5), transmembrane p24 trafficking protein (TMED2), and delta 4-desaturase sphingolipid 1 (DEGS1) were characterized as the 4 receptors of EmMAR2 by both assays. By blocking the interaction of EmMAR2 with each receptor using specific antibodies, we observed varying levels of inhibition on the invasion of E. maxima sporozoites, and the combined usage of all 4 antibodies resulted in the most pronounced inhibitory effect. Additionally, the spatio-temporal expression profiles of ATP6V1G1, REEP5, TMED2, and DEGS1 were assessed. The tissue-specific expression patterns of EmMAR2 receptors throughout E. maxima infection suggested that ATP6V1G1 and DEGS1 might play a role in early-stage invasion, whereas TMED2 could be involved in middle and late-stage invasion and REEP5 and DEGS1 may participate primarily in late-stage invasion. Consequently, E. maxima may employ a multitude of ligand-receptor interactions to drive invasion during different stages of infection. This study marks the first report of EmMAR2 receptors at the interface between E. maxima and the host, providing insights into the invasion mechanisms of E. maxima and the pathogenesis of coccidiosis.
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Affiliation(s)
- Yang Zhang
- MOE Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing 210095, People's Republic of China
| | - Mingmin Lu
- MOE Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing 210095, People's Republic of China
| | - Jianmei Huang
- MOE Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing 210095, People's Republic of China
| | - Xiaowei Tian
- MOE Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing 210095, People's Republic of China
| | - Meng Liang
- MOE Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing 210095, People's Republic of China
| | - Mingyue Wang
- MOE Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing 210095, People's Republic of China
| | - Xiaokai Song
- MOE Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing 210095, People's Republic of China
| | - Lixin Xu
- MOE Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing 210095, People's Republic of China
| | - Ruofeng Yan
- MOE Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing 210095, People's Republic of China
| | - Xiangrui Li
- MOE Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing 210095, People's Republic of China.
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Sun L, Li C, Zhao N, Wang B, Li H, Wang H, Zhang X, Zhao X. Host protein EPCAM interacting with EtMIC8-EGF is essential for attachment and invasion of Eimeria tenella in chickens. Microb Pathog 2024; 188:106549. [PMID: 38281605 DOI: 10.1016/j.micpath.2024.106549] [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: 10/10/2023] [Revised: 01/12/2024] [Accepted: 01/15/2024] [Indexed: 01/30/2024]
Abstract
The five epidermal growth factor-like domains (EGF) of Eimeria tenella microneme protein 8 (EtMIC8) (EtMIC8-EGF) plays a vital role in host cell attachment and invasion. These processes require interactions between parasite proteins and receptors on the surface of host cells. In this study, five chicken membrane proteins potentially interacting with EtMIC8-EGF were identified using the GST pull-down assay and mass spectrometry analysis, and only chicken (Gallus gallus) epithelial cell adhesion molecule (EPCAM) could bind to EtMIC8-EGF. EPCAM-specific antibody and recombinant EPCAM protein (rEPCAM) inhibited the EtMIC8-EGF binding to host cells in a concentration-dependent manner. Furthermore, the rEPCAM protein showed a binding activity to sporozoites in vitro, and a significant reduction of E. tenella invasion in DF-1 cells was further observed after pre-incubation of sporozoites with rEPCAM. The specific anti-EPCAM antibody further significantly decreased weight loss, lesion score and oocyst output during E. tenella infection, displaying partial inhibition of E. tenella infection. These results indicate that chicken EPCAM is an important EtMIC8-interacting host protein involved in E. tenella-host cell adhesion and invasion. The findings will contribute to a better understanding of the role of adhesion-associated microneme proteins in E. tenella.
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Affiliation(s)
- Lingyu Sun
- Department of Preventive Veterinary Medicine, College of Veterinary Medicine, Shandong Agricultural University, Tai'an City, Shandong Province, China; Shandong Provincial Key Laboratory of Animal Biotechnology and Disease Control and Prevention, Shandong Agricultural University, Tai'an City, Shandong Province, China; Shandong Provincial Engineering Technology Research Center of Animal Disease Control and Prevention, Shandong Agricultural University, 61 Daizong Street, Tai'an City, 271018, Shandong Province, China
| | - Chao Li
- College of Veterinary Medicine, Hebei Agricultural University, Baoding City, 071000, Hebei Province, China
| | - Ningning Zhao
- Department of Preventive Veterinary Medicine, College of Veterinary Medicine, Shandong Agricultural University, Tai'an City, Shandong Province, China; Shandong Provincial Key Laboratory of Animal Biotechnology and Disease Control and Prevention, Shandong Agricultural University, Tai'an City, Shandong Province, China; Shandong Provincial Engineering Technology Research Center of Animal Disease Control and Prevention, Shandong Agricultural University, 61 Daizong Street, Tai'an City, 271018, Shandong Province, China
| | - Bingxiang Wang
- Shandong Vocational Animal Science and Veterinary College, Weifang City, Shandong Province, China
| | - Hongmei Li
- Department of Preventive Veterinary Medicine, College of Veterinary Medicine, Shandong Agricultural University, Tai'an City, Shandong Province, China; Shandong Provincial Key Laboratory of Animal Biotechnology and Disease Control and Prevention, Shandong Agricultural University, Tai'an City, Shandong Province, China; Shandong Provincial Engineering Technology Research Center of Animal Disease Control and Prevention, Shandong Agricultural University, 61 Daizong Street, Tai'an City, 271018, Shandong Province, China
| | - Hairong Wang
- Department of Preventive Veterinary Medicine, College of Veterinary Medicine, Shandong Agricultural University, Tai'an City, Shandong Province, China; Shandong Provincial Key Laboratory of Animal Biotechnology and Disease Control and Prevention, Shandong Agricultural University, Tai'an City, Shandong Province, China; Shandong Provincial Engineering Technology Research Center of Animal Disease Control and Prevention, Shandong Agricultural University, 61 Daizong Street, Tai'an City, 271018, Shandong Province, China
| | - Xiao Zhang
- Department of Preventive Veterinary Medicine, College of Veterinary Medicine, Shandong Agricultural University, Tai'an City, Shandong Province, China; Shandong Provincial Key Laboratory of Animal Biotechnology and Disease Control and Prevention, Shandong Agricultural University, Tai'an City, Shandong Province, China; Shandong Provincial Engineering Technology Research Center of Animal Disease Control and Prevention, Shandong Agricultural University, 61 Daizong Street, Tai'an City, 271018, Shandong Province, China.
| | - Xiaomin Zhao
- Department of Preventive Veterinary Medicine, College of Veterinary Medicine, Shandong Agricultural University, Tai'an City, Shandong Province, China; Shandong Provincial Key Laboratory of Animal Biotechnology and Disease Control and Prevention, Shandong Agricultural University, Tai'an City, Shandong Province, China; Shandong Provincial Engineering Technology Research Center of Animal Disease Control and Prevention, Shandong Agricultural University, 61 Daizong Street, Tai'an City, 271018, Shandong Province, China.
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3
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Lin YC, Sahoo BK, Gau SS, Yang RB. The biology of SCUBE. J Biomed Sci 2023; 30:33. [PMID: 37237303 PMCID: PMC10214685 DOI: 10.1186/s12929-023-00925-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2023] [Accepted: 05/04/2023] [Indexed: 05/28/2023] Open
Abstract
The SCUBE [Signal peptide-Complement C1r/C1s, Uegf, Bmp1 (CUB)-Epithelial growth factor domain-containing protein] family consists of three proteins in vertebrates, SCUBE1, 2 and 3, which are highly conserved in zebrafish, mice and humans. Each SCUBE gene encodes a polypeptide of approximately 1000 amino acids that is organized into five modular domains: (1) an N-terminal signal peptide sequence, (2) nine tandem epidermal growth factor (EGF)-like repeats, (3) a large spacer region, (4) three cysteine-rich (CR) motifs, and (5) a CUB domain at the C-terminus. Murine Scube genes are expressed individually or in combination during the development of various tissues, including those in the central nervous system and the axial skeleton. The cDNAs of human SCUBE orthologs were originally cloned from vascular endothelial cells, but SCUBE expression has also been found in platelets, mammary ductal epithelium and osteoblasts. Both soluble and membrane-associated SCUBEs have been shown to play important roles in physiology and pathology. For instance, upregulation of SCUBEs has been reported in acute myeloid leukemia, breast cancer and lung cancer. In addition, soluble SCUBE1 is released from activated platelets and can be used as a clinical biomarker for acute coronary syndrome and ischemic stroke. Soluble SCUBE2 enhances distal signaling by facilitating the secretion of dual-lipidated hedgehog from nearby ligand-producing cells in a paracrine manner. Interestingly, the spacer regions and CR motifs can increase or enable SCUBE binding to cell surfaces via electrostatic or glycan-lectin interactions. As such, membrane-associated SCUBEs can function as coreceptors that enhance the signaling activity of various serine/threonine kinase or tyrosine kinase receptors. For example, membrane-associated SCUBE3 functions as a coreceptor that promotes signaling in bone morphogenesis. In humans, SCUBE3 mutations are linked to abnormalities in growth and differentiation of both bones and teeth. In addition to studies on human SCUBE function, experimental results from genetically modified mouse models have yielded important insights in the field of systems biology. In this review, we highlight novel molecular discoveries and critical directions for future research on SCUBE proteins in the context of cancer, skeletal disease and cardiovascular disease.
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Affiliation(s)
- Yuh-Charn Lin
- Department of Physiology, School of Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan
| | - Binay K Sahoo
- Institute of Biomedical Sciences, Academia Sinica, Taipei, Taiwan
| | - Shiang-Shin Gau
- Institute of Biomedical Sciences, Academia Sinica, Taipei, Taiwan
| | - Ruey-Bing Yang
- Institute of Biomedical Sciences, Academia Sinica, Taipei, Taiwan.
- Biomedical Translation Research Center, Academia Sinica, Taipei, Taiwan.
- Program in Drug Discovery and Development Industry, College of Pharmacy, Taipei Medical University, Taipei, Taiwan.
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Zhang XS, Zhao YJ, Zhang Y, Xu T, Cui KL, Duan BT, Lv XL, Zhang L, Xu ZY, Bai R, Zheng MX. Role of EtMIC4 EGF-like in regulating the apoptosis of Eimeria tenella host cells via the EGFR pathway. Poult Sci 2022; 101:102075. [PMID: 36041391 PMCID: PMC9449671 DOI: 10.1016/j.psj.2022.102075] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2022] [Revised: 07/06/2022] [Accepted: 07/19/2022] [Indexed: 11/25/2022] Open
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Chapman HD, Barta JR, Blake D, Gruber A, Jenkins M, Smith NC, Suo X, Tomley FM. A selective review of advances in coccidiosis research. ADVANCES IN PARASITOLOGY 2014; 83:93-171. [PMID: 23876872 DOI: 10.1016/b978-0-12-407705-8.00002-1] [Citation(s) in RCA: 161] [Impact Index Per Article: 16.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Coccidiosis is a widespread and economically significant disease of livestock caused by protozoan parasites of the genus Eimeria. This disease is worldwide in occurrence and costs the animal agricultural industry many millions of dollars to control. In recent years, the modern tools of molecular biology, biochemistry, cell biology and immunology have been used to expand greatly our knowledge of these parasites and the disease they cause. Such studies are essential if we are to develop new means for the control of coccidiosis. In this chapter, selective aspects of the biology of these organisms, with emphasis on recent research in poultry, are reviewed. Topics considered include taxonomy, systematics, genetics, genomics, transcriptomics, proteomics, transfection, oocyst biogenesis, host cell invasion, immunobiology, diagnostics and control.
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Affiliation(s)
- H David Chapman
- Department of Poultry Science, University of Arkansas, Fayetteville, Arkansas, USA.
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Smith AD, Reuben Kaufman W. Molecular characterization of the vitellogenin receptor from the tick, Amblyomma hebraeum (Acari: Ixodidae). INSECT BIOCHEMISTRY AND MOLECULAR BIOLOGY 2013; 43:1133-1141. [PMID: 24128609 DOI: 10.1016/j.ibmb.2013.10.002] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/30/2013] [Revised: 10/01/2013] [Accepted: 10/04/2013] [Indexed: 06/02/2023]
Abstract
We have identified the full-length cDNA encoding a vitellogenin receptor (VgR) from the African bont tick Amblyomma hebraeum Koch (1844). VgRs are members of the low-density lipoprotein receptor superfamily that promote the uptake of the yolk protein vitellogenin (Vg), from the haemolymph. The AhVgR (GenBank accession No. JX846592) is 5703 bp, and encodes an 1801 aa protein with a 196.5 kDa molecular mass following cleavage of a 22 aa signal peptide. Phylogenetic analysis indicates that AhVgR is highly similar to other tick VgRs. AhVgR is expressed in only the ovary of mated, engorged females, and is absent in all other female tissues and in both fed and unfed males. Unfed, adult females injected with a VgR-dsRNA probe to knock-down VgR expression experienced a significant delay in ovary development and started oviposition significantly later than controls. These results indicate that the expression of AhVgR is important for the uptake of Vg and subsequent maturation of the oocytes.
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Affiliation(s)
- Alexander D Smith
- Department of Biological Sciences, University of Alberta, CW 405, Biological Sciences Building, Edmonton, Alberta T6G 2E9, Canada.
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Huber RJ, O'Day DH. A matricellular protein and EGF-like repeat signalling in the social amoebozoan Dictyostelium discoideum. Cell Mol Life Sci 2012; 69:3989-97. [PMID: 22782112 PMCID: PMC11115030 DOI: 10.1007/s00018-012-1068-4] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2012] [Revised: 06/18/2012] [Accepted: 06/19/2012] [Indexed: 12/13/2022]
Abstract
Matricellular proteins interact with the extracellular matrix (ECM) and modulate cellular processes by binding to cell surface receptors and initiating intracellular signal transduction. Their association with the ECM and the ability of some members of this protein family to regulate cell motility have opened up new avenues of research to investigate their functions in normal and diseased cells. In this review, we summarize the research on CyrA, an ECM calmodulin-binding protein in Dictyostelium. CyrA is proteolytically cleaved into smaller EGF-like (EGFL) repeat containing cleavage products during development. The first EGFL repeat of CyrA binds to the cell surface and activates a novel signalling pathway that modulates cell motility in this model organism. The similarity of CyrA to the most well-characterized matricellular proteins in mammals allows it to be designated as the first matricellular protein identified in Dictyostelium.
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Affiliation(s)
- Robert J Huber
- Department of Cell and Systems Biology, University of Toronto, 25 Harbord Street, Toronto, ON, M5S 3G5, Canada,
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8
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Twigg S, Lloyd D, Jenkins D, Elçioglu N, Cooper C, Al-Sannaa N, Annagür A, Gillessen-Kaesbach G, Hüning I, Knight S, Goodship J, Keavney B, Beales P, Gileadi O, McGowan S, Wilkie A. Mutations in multidomain protein MEGF8 identify a Carpenter syndrome subtype associated with defective lateralization. Am J Hum Genet 2012; 91:897-905. [PMID: 23063620 DOI: 10.1016/j.ajhg.2012.08.027] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2012] [Revised: 08/13/2012] [Accepted: 08/27/2012] [Indexed: 10/27/2022] Open
Abstract
Carpenter syndrome is an autosomal-recessive multiple-congenital-malformation disorder characterized by multisuture craniosynostosis and polysyndactyly of the hands and feet; many other clinical features occur, and the most frequent include obesity, umbilical hernia, cryptorchidism, and congenital heart disease. Mutations of RAB23, encoding a small GTPase that regulates vesicular transport, are present in the majority of cases. Here, we describe a disorder caused by mutations in multiple epidermal-growth-factor-like-domains 8 (MEGF8), which exhibits substantial clinical overlap with Carpenter syndrome but is frequently associated with abnormal left-right patterning. We describe five affected individuals with similar dysmorphic facies, and three of them had either complete situs inversus, dextrocardia, or transposition of the great arteries; similar cardiac abnormalities were previously identified in a mouse mutant for the orthologous Megf8. The mutant alleles comprise one nonsense, three missense, and two splice-site mutations; we demonstrate in zebrafish that, in contrast to the wild-type protein, the proteins containing all three missense alterations provide only weak rescue of an early gastrulation phenotype induced by Megf8 knockdown. We conclude that mutations in MEGF8 cause a Carpenter syndrome subtype frequently associated with defective left-right patterning, probably through perturbation of signaling by hedgehog and nodal family members. We did not observe any subject with biallelic loss-of function mutations, suggesting that some residual MEGF8 function might be necessary for survival and might influence the phenotypes observed.
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Zhou BH, Wang HW, Wang XY, Zhang LF, Zhang KY, Xue FQ. Eimeria tenella: effects of diclazuril treatment on microneme genes expression in second-generation merozoites and pathological changes of caeca in parasitized chickens. Exp Parasitol 2010; 125:264-70. [PMID: 20138868 DOI: 10.1016/j.exppara.2010.01.022] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2009] [Revised: 01/26/2010] [Accepted: 01/27/2010] [Indexed: 01/09/2023]
Abstract
The effects of diclazuril on mRNA expression levels of invasion-related microneme genes were examined in second-generation merozoites of Eimeria tenella (E. tenella) by quantitative real-time (QRT) PCR. Diclazruil treatment of infected chickens significantly decreased the number of second-generation merozoites by 65.13%, and resulted in downregulation of EtMIC genes: EtMIC1 by 65.63%, EtMIC2 by 64.12%, EtMIC3 by 56.82%, EtMIC4 by 73.48%, and EtMIC5 by 78.17%. SEM images of caecum tissue from uninfected chickens showed regular intestinal villus structure. In infected chickens, a distinct loss of the superficial epithelium, with a flattened mucosa and large-area necrosis and anabrosis, was evident. In diclazruil-treated chickens, a decrease in merozoite number and a visibly improved appearance of the caeca were noted. These improvements appeared to be mediated in part by downregulation of the expression of invasion-related EtMIC genes in response to diclazuril.
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Affiliation(s)
- Bian-hua Zhou
- Key Laboratory of Veterinary Drug Safety Evaluation and Residues Research, Chinese Academy of Agricultural Sciences, Key Laboratory of Animal Parasitology of Ministry of Agriculture, Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai, People's Republic of China
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Abstract
Microneme secretion supports several key cellular processes including gliding motility, active cell invasion and migration through cells, biological barriers, and tissues. The modular design of microneme proteins enables these molecules to assist each other in folding and passage through the quality control system, accurately target to the micronemes, oligimerizing with other parasite proteins, and engaging a variety of host receptors for migration and cell invasion. Structural and biochemical analyses of MIC domains is providing new perspectives on how adhesion is regulated and the potentially distinct roles MICs might play in long or short range interactions during parasite attachment and entry. New access to complete genome sequences and ongoing advances in genetic manipulation should provide fertile ground for refining current models and defining exciting new roles for MICs in apicomplexan biology.
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Affiliation(s)
- Vern B Carruthers
- Department of Microbiology and Immunology, University of Michigan School of Medicine, Ann Arbor, Michigan 48109, USA.
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Cummins SF, Xie F, de Vries MR, Annangudi SP, Misra M, Degnan BM, Sweedler JV, Nagle GT, Schein CH. Aplysia temptin - the 'glue' in the water-borne attractin pheromone complex. FEBS J 2007; 274:5425-37. [PMID: 17894821 DOI: 10.1111/j.1742-4658.2007.06070.x] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Temptin, a component of the complex of water-borne protein pheromones that stimulate attraction and mating behavior in the marine mollusk Aplysia, has sequence homology to the epidermal growth factor (EGF)-like domains of higher organisms that mediate protein-cell surface contact during fertilization and blood coagulation. In this work, recombinant temptin for structural and functional studies was produced in Escherichia coli using a cold shock promoter and purified by RP-HPLC. CD spectra confirmed a predominantly beta-sheet structure. Two disulfide bonds were determined via limited proteolysis and MS. One internal disulfide (Cys57-Cys77) was predicted from initial alignments with class I EGF-like domains; the second, between Cys18 and Cys103, could protect temptin against proteolysis in seawater and stabilize its interacting surface. A three-dimensional model of temptin was prepared with our MPACK suite, based on the Ca(2+)-binding, EGF-like domain of the extracellular matrix protein fibrillin. Two temptin residues, Trp52 and Trp79, which align with cysteine residues conserved in fibrillins, lie adjacent to and could stabilize the disulfide bonds and a proposed metal-binding loop. The water-borne pheromone attractin in egg cordon eluates is complexed with other proteins. Docking results with our model and the NMR structure of attractin suggest that one face of temptin interacts with the pheromone, perhaps controlling its access to the cellular receptors. Gel shifts confirmed that temptin complexes with wild-type attractin. These results indicate that temptin, analogous to the role of fibrillin in controlling transforming growth factor-beta concentration, modulates pheromone signaling by direct binding to attractin.
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Affiliation(s)
- Scott F Cummins
- Department of Neuroscience and Cell Biology, University of Texas Medical Branch, Galveston, TX 77555-0857, USA
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Periz J, Gill AC, Hunt L, Brown P, Tomley FM. The Microneme Proteins EtMIC4 and EtMIC5 of Eimeria tenella Form a Novel, Ultra-high Molecular Mass Protein Complex That Binds Target Host Cells. J Biol Chem 2007; 282:16891-8. [PMID: 17426025 DOI: 10.1074/jbc.m702407200] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Eimeria tenella, in common with other parasitic protozoa of the phylum Apicomplexa, invades host cells using an actinomyosin-powered "glideosome" complex and requires the secretion of adhesive proteins from the microneme organelles onto the parasite surface. Microneme proteins of E. tenella include EtMIC4, a transmembrane protein that has multiple thrombospondin type I domains and calcium-binding epidermal growth factor-like domains in its extracellular domain, and EtMIC5, a soluble protein composed of 11 tandemly repeated domains that belong to the plasminogen-apple-nematode superfamily. We show here that EtMIC4 and EtMIC5 interact to form an oligomeric, ultrahigh molecular mass protein complex. The complex was purified from lysed parasites by non-denaturing techniques, and the stoichiometry was shown to be [EtMIC4](2):[EtMIC5](1), with an octamer of EtMIC4 bound non-covalently to a tetramer of EtMIC5. The complex is formed within the parasite secretory pathway and is maintained after secretion onto the surface of the parasite. The purified complex binds to a number of epithelial cell lines in culture. Identification and characterization of this complex contributes to an overall understanding of the role of multimolecular protein complexes in specific interactions between pathogens and their hosts during infection.
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Affiliation(s)
- Javier Periz
- Institute for Animal Health, Compton, Newbury, Berkshire, RG20 7NN United Kingdom
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Mitchell RD, Ross E, Osgood C, Sonenshine DE, Donohue KV, Khalil SM, Thompson DM, Michael Roe R. Molecular characterization, tissue-specific expression and RNAi knockdown of the first vitellogenin receptor from a tick. INSECT BIOCHEMISTRY AND MOLECULAR BIOLOGY 2007; 37:375-88. [PMID: 17368201 DOI: 10.1016/j.ibmb.2007.01.005] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/05/2006] [Revised: 01/04/2007] [Accepted: 01/05/2007] [Indexed: 05/14/2023]
Abstract
This is the first full-length message for a vitellogenin receptor (VgR) sequenced from ticks. VgRs, members of the low-density lipoprotein receptor (LDLR) superfamily, mediate the uptake of the yolk protein, vitellogenin (Vg), from the hemolymph. The VgR message from the American dog tick, Dermacentor variabilis (GenBank accession No. DQ103506.4) comprised 5673 bp which coded for a 1798 aa deduced protein with a predicted 196.6 kDa molecular mass. After removing the 20 aa signal peptide, the 1778 aa deduced mature protein had a predicted 196.6 kDa molecular mass. BLAST comparisons showed the highest similarity to the VgR of the cockroach, Periplaneta americana. VgR message was expressed in mated female ovary but absent in female midgut and salivary glands or whole body mRNA from blood fed males, indicating that it is both sex and tissue specific. VgR transcript was absent in virgin (previtellogenic) females but present in ovaries of mated females following drop off. RNAi showed that unfed adult ticks injected with a VgR-dsRNA probe failed to lay eggs, develop brown eggs or fully express VgR transcript (Northern blots). In contrast, controls oviposited numerous normal brown eggs and showed strong expression of VgR transcripts. These results show that the expression of the VgR message is essential for Vg uptake and egg development in the American dog tick.
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Affiliation(s)
- Robert D Mitchell
- Department of Biological Sciences, Old Dominion University, Norfolk, VA 23529, USA
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14
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Abstract
Secretory processes play an important role on the biology and life cycles of parasitic protozoa. This review focus on basic aspects, from a cell biology perspective, of the secretion of (a) micronemes, rhoptries and dense granules in members of the Apicomplexa group, where these organelles are involved in the process of protozoan penetration into the host cell, survival within the parasitophorous vacuole and subsequent egress from the host cell, (b) the Maurer's cleft in Plasmodium, a structure involved in the secretion of proteins synthesized by the intravacuolar parasite and transported through vesicles to the erythrocyte surface, (c) the secretion of macromolecules into the flagellar pocket of trypanosomatids, and (d) the secretion of proteins which make the cyst wall of Giardia and Entamoeba, with the formation of encystation vesicles.
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Affiliation(s)
- Wanderley de Souza
- Laboratório de Ultraestrutura Celular Hertha Meyer, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Ilha do Fundão, 21949-900 Rio de Janeiro, RJ, Brazil.
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