The mucin-like, secretory type-I transmembrane glycoprotein GP900 in the apicomplexan Cryptosporidium parvum is cleaved in the secretory pathway and likely plays a lubrication role
Abstract Background Cryptosporidium parvum is a zoonotic parasite and member of the phylum Apicomplexa with unique secretory organelles, including a rhoptry, micronemes and dense granules that discharge their contents during parasite invasion. The mucin-like glycoprotein GP900 with a single transmem...
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BMC
2022-05-01
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| Series: | Parasites & Vectors |
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| Online Access: | https://doi.org/10.1186/s13071-022-05286-8 |
| _version_ | 1811248839360774144 |
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| author | Xiaohui Li Jigang Yin Dongqiang Wang Xin Gao Ying Zhang Mingbo Wu Guan Zhu |
| author_facet | Xiaohui Li Jigang Yin Dongqiang Wang Xin Gao Ying Zhang Mingbo Wu Guan Zhu |
| author_sort | Xiaohui Li |
| collection | DOAJ |
| description | Abstract Background Cryptosporidium parvum is a zoonotic parasite and member of the phylum Apicomplexa with unique secretory organelles, including a rhoptry, micronemes and dense granules that discharge their contents during parasite invasion. The mucin-like glycoprotein GP900 with a single transmembrane domain is an immunodominant antigen and micronemal protein. It is relocated to the surface of excysted sporozoites and shed to form trails by sporozoites exhibiting gliding motility (gliding sporozoites). However, the biological process underlying its relocation and shedding remains unclear. The primary aim of this study was to determine whether GP900 is present as a transmembrane protein anchored to the plasma membrane on the surface of sporozoites and whether it is cleaved before being shed from the sporozoites. Methods Two anti-GP900 antibodies, a mouse monoclonal antibody (mAb) to the long N-terminal domain (GP900-N) and a rabbit polyclonal antibody (pAb) to the short C-terminal domain (GP900-C), were produced for the detection of intact and cleaved GP900 proteins in sporozoites and other parasite developmental stages by microscopic immunofluorescence assay and in discharged molecules by enzyme-linked immunosorbent assay. Results Both anti-GP900 antibodies recognized the apical region of unexcysted and excysted sporozoites. However, anti-GP900-N (but not anti-GP900-C) also stained both the pellicles/surface of excysted sporozoites and the trails of gliding sporozoites. Both antibodies stained the intracellular meronts, both developing and developed, but not the macro- and microgamonts. Additionally, the epitope was recognized by anti-GP900-N (but not anti-GP900-C) and detected in the secretions of excysted sporozoites and intracellular parasites. Conclusions GP900 is present in sporozoites and intracellular meronts, but absent in sexual stages. It is stored in the micronemes of sporozoites, but enters the secretory pathway during excystation and invasion. The short cytoplasmic domain of GP900 is cleaved in the secretory pathway before it reaches the extracellular space. The molecular features and behavior of GP900 imply that it plays mainly a lubrication role. Graphical Abstract |
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| institution | Directory Open Access Journal |
| issn | 1756-3305 |
| language | English |
| last_indexed | 2024-04-12T15:35:04Z |
| publishDate | 2022-05-01 |
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| spelling | doaj.art-e95ee57ddf674ec3b3216c06d0e66b512022-12-22T03:26:59ZengBMCParasites & Vectors1756-33052022-05-0115111510.1186/s13071-022-05286-8The mucin-like, secretory type-I transmembrane glycoprotein GP900 in the apicomplexan Cryptosporidium parvum is cleaved in the secretory pathway and likely plays a lubrication roleXiaohui Li0Jigang Yin1Dongqiang Wang2Xin Gao3Ying Zhang4Mingbo Wu5Guan Zhu6Key Laboratory of Zoonosis Research of the Ministry of Education, The Institute of Zoonosis, The College of Veterinary Medicine, Jilin UniversityKey Laboratory of Zoonosis Research of the Ministry of Education, The Institute of Zoonosis, The College of Veterinary Medicine, Jilin UniversityKey Laboratory of Zoonosis Research of the Ministry of Education, The Institute of Zoonosis, The College of Veterinary Medicine, Jilin UniversityKey Laboratory of Zoonosis Research of the Ministry of Education, The Institute of Zoonosis, The College of Veterinary Medicine, Jilin UniversityKey Laboratory of Zoonosis Research of the Ministry of Education, The Institute of Zoonosis, The College of Veterinary Medicine, Jilin UniversityKey Laboratory of Zoonosis Research of the Ministry of Education, The Institute of Zoonosis, The College of Veterinary Medicine, Jilin UniversityKey Laboratory of Zoonosis Research of the Ministry of Education, The Institute of Zoonosis, The College of Veterinary Medicine, Jilin UniversityAbstract Background Cryptosporidium parvum is a zoonotic parasite and member of the phylum Apicomplexa with unique secretory organelles, including a rhoptry, micronemes and dense granules that discharge their contents during parasite invasion. The mucin-like glycoprotein GP900 with a single transmembrane domain is an immunodominant antigen and micronemal protein. It is relocated to the surface of excysted sporozoites and shed to form trails by sporozoites exhibiting gliding motility (gliding sporozoites). However, the biological process underlying its relocation and shedding remains unclear. The primary aim of this study was to determine whether GP900 is present as a transmembrane protein anchored to the plasma membrane on the surface of sporozoites and whether it is cleaved before being shed from the sporozoites. Methods Two anti-GP900 antibodies, a mouse monoclonal antibody (mAb) to the long N-terminal domain (GP900-N) and a rabbit polyclonal antibody (pAb) to the short C-terminal domain (GP900-C), were produced for the detection of intact and cleaved GP900 proteins in sporozoites and other parasite developmental stages by microscopic immunofluorescence assay and in discharged molecules by enzyme-linked immunosorbent assay. Results Both anti-GP900 antibodies recognized the apical region of unexcysted and excysted sporozoites. However, anti-GP900-N (but not anti-GP900-C) also stained both the pellicles/surface of excysted sporozoites and the trails of gliding sporozoites. Both antibodies stained the intracellular meronts, both developing and developed, but not the macro- and microgamonts. Additionally, the epitope was recognized by anti-GP900-N (but not anti-GP900-C) and detected in the secretions of excysted sporozoites and intracellular parasites. Conclusions GP900 is present in sporozoites and intracellular meronts, but absent in sexual stages. It is stored in the micronemes of sporozoites, but enters the secretory pathway during excystation and invasion. The short cytoplasmic domain of GP900 is cleaved in the secretory pathway before it reaches the extracellular space. The molecular features and behavior of GP900 imply that it plays mainly a lubrication role. Graphical Abstracthttps://doi.org/10.1186/s13071-022-05286-8ApicomplexanCryptosporidium parvumMicroneme proteinsGlycoprotein GP900Domain cleavage |
| spellingShingle | Xiaohui Li Jigang Yin Dongqiang Wang Xin Gao Ying Zhang Mingbo Wu Guan Zhu The mucin-like, secretory type-I transmembrane glycoprotein GP900 in the apicomplexan Cryptosporidium parvum is cleaved in the secretory pathway and likely plays a lubrication role Parasites & Vectors Apicomplexan Cryptosporidium parvum Microneme proteins Glycoprotein GP900 Domain cleavage |
| title | The mucin-like, secretory type-I transmembrane glycoprotein GP900 in the apicomplexan Cryptosporidium parvum is cleaved in the secretory pathway and likely plays a lubrication role |
| title_full | The mucin-like, secretory type-I transmembrane glycoprotein GP900 in the apicomplexan Cryptosporidium parvum is cleaved in the secretory pathway and likely plays a lubrication role |
| title_fullStr | The mucin-like, secretory type-I transmembrane glycoprotein GP900 in the apicomplexan Cryptosporidium parvum is cleaved in the secretory pathway and likely plays a lubrication role |
| title_full_unstemmed | The mucin-like, secretory type-I transmembrane glycoprotein GP900 in the apicomplexan Cryptosporidium parvum is cleaved in the secretory pathway and likely plays a lubrication role |
| title_short | The mucin-like, secretory type-I transmembrane glycoprotein GP900 in the apicomplexan Cryptosporidium parvum is cleaved in the secretory pathway and likely plays a lubrication role |
| title_sort | mucin like secretory type i transmembrane glycoprotein gp900 in the apicomplexan cryptosporidium parvum is cleaved in the secretory pathway and likely plays a lubrication role |
| topic | Apicomplexan Cryptosporidium parvum Microneme proteins Glycoprotein GP900 Domain cleavage |
| url | https://doi.org/10.1186/s13071-022-05286-8 |
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