Cysteine and Aspartyl Proteases Contribute to Protein Digestion in the Gut of Freshwater Planaria.
Proteases perform numerous vital functions in flatworms, many of which are likely to be conserved throughout the phylum Platyhelminthes. Within this phylum are several parasitic worms that are often poorly characterized due to their complex life-cycles and lack of responsiveness to genetic manipulat...
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ftdoajarticles:oai:doaj.org/article:40ef71f4033643a6bc3c7941a770802a 2023-05-15T15:13:53+02:00 Cysteine and Aspartyl Proteases Contribute to Protein Digestion in the Gut of Freshwater Planaria. Louise S Goupil Sam L Ivry Ivy Hsieh Brian M Suzuki Charles S Craik Anthony J O'Donoghue James H McKerrow 2016-08-01T00:00:00Z https://doi.org/10.1371/journal.pntd.0004893 https://doaj.org/article/40ef71f4033643a6bc3c7941a770802a EN eng Public Library of Science (PLoS) http://europepmc.org/articles/PMC4976874?pdf=render https://doaj.org/toc/1935-2727 https://doaj.org/toc/1935-2735 1935-2727 1935-2735 doi:10.1371/journal.pntd.0004893 https://doaj.org/article/40ef71f4033643a6bc3c7941a770802a PLoS Neglected Tropical Diseases, Vol 10, Iss 8, p e0004893 (2016) Arctic medicine. Tropical medicine RC955-962 Public aspects of medicine RA1-1270 article 2016 ftdoajarticles https://doi.org/10.1371/journal.pntd.0004893 2022-12-31T08:58:02Z Proteases perform numerous vital functions in flatworms, many of which are likely to be conserved throughout the phylum Platyhelminthes. Within this phylum are several parasitic worms that are often poorly characterized due to their complex life-cycles and lack of responsiveness to genetic manipulation. The flatworm Schmidtea mediterranea, or planaria, is an ideal model organism to study the complex role of protein digestion due to its simple life cycle and amenability to techniques like RNA interference (RNAi). In this study, we were interested in deconvoluting the digestive protease system that exists in the planarian gut. To do this, we developed an alcohol-induced regurgitation technique to enrich for the gut enzymes in S. mediterranea. Using a panel of fluorescent substrates, we show that this treatment produces a sharp increase in proteolytic activity. These enzymes have broad yet diverse substrate specificity profiles. Proteomic analysis of the gut contents revealed the presence of cysteine and metallo-proteases. However, treatment with class-specific inhibitors showed that aspartyl and cysteine proteases are responsible for the majority of protein digestion. Specific RNAi knockdown of the cathepsin B-like cysteine protease (SmedCB) reduced protein degradation in vivo. Immunohistochemistry and whole-mount in situ hybridization (WISH) confirmed that the full-length and active forms of SmedCB are found in secretory cells surrounding the planaria intestinal lumen. Finally, we show that the knockdown of SmedCB reduces the speed of tissue regeneration. Defining the roles of proteases in planaria can provide insight to functions of conserved proteases in parasitic flatworms, potentially uncovering drug targets in parasites. Article in Journal/Newspaper Arctic Directory of Open Access Journals: DOAJ Articles Arctic PLOS Neglected Tropical Diseases 10 8 e0004893 |
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Open Polar |
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Directory of Open Access Journals: DOAJ Articles |
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ftdoajarticles |
language |
English |
topic |
Arctic medicine. Tropical medicine RC955-962 Public aspects of medicine RA1-1270 |
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Arctic medicine. Tropical medicine RC955-962 Public aspects of medicine RA1-1270 Louise S Goupil Sam L Ivry Ivy Hsieh Brian M Suzuki Charles S Craik Anthony J O'Donoghue James H McKerrow Cysteine and Aspartyl Proteases Contribute to Protein Digestion in the Gut of Freshwater Planaria. |
topic_facet |
Arctic medicine. Tropical medicine RC955-962 Public aspects of medicine RA1-1270 |
description |
Proteases perform numerous vital functions in flatworms, many of which are likely to be conserved throughout the phylum Platyhelminthes. Within this phylum are several parasitic worms that are often poorly characterized due to their complex life-cycles and lack of responsiveness to genetic manipulation. The flatworm Schmidtea mediterranea, or planaria, is an ideal model organism to study the complex role of protein digestion due to its simple life cycle and amenability to techniques like RNA interference (RNAi). In this study, we were interested in deconvoluting the digestive protease system that exists in the planarian gut. To do this, we developed an alcohol-induced regurgitation technique to enrich for the gut enzymes in S. mediterranea. Using a panel of fluorescent substrates, we show that this treatment produces a sharp increase in proteolytic activity. These enzymes have broad yet diverse substrate specificity profiles. Proteomic analysis of the gut contents revealed the presence of cysteine and metallo-proteases. However, treatment with class-specific inhibitors showed that aspartyl and cysteine proteases are responsible for the majority of protein digestion. Specific RNAi knockdown of the cathepsin B-like cysteine protease (SmedCB) reduced protein degradation in vivo. Immunohistochemistry and whole-mount in situ hybridization (WISH) confirmed that the full-length and active forms of SmedCB are found in secretory cells surrounding the planaria intestinal lumen. Finally, we show that the knockdown of SmedCB reduces the speed of tissue regeneration. Defining the roles of proteases in planaria can provide insight to functions of conserved proteases in parasitic flatworms, potentially uncovering drug targets in parasites. |
format |
Article in Journal/Newspaper |
author |
Louise S Goupil Sam L Ivry Ivy Hsieh Brian M Suzuki Charles S Craik Anthony J O'Donoghue James H McKerrow |
author_facet |
Louise S Goupil Sam L Ivry Ivy Hsieh Brian M Suzuki Charles S Craik Anthony J O'Donoghue James H McKerrow |
author_sort |
Louise S Goupil |
title |
Cysteine and Aspartyl Proteases Contribute to Protein Digestion in the Gut of Freshwater Planaria. |
title_short |
Cysteine and Aspartyl Proteases Contribute to Protein Digestion in the Gut of Freshwater Planaria. |
title_full |
Cysteine and Aspartyl Proteases Contribute to Protein Digestion in the Gut of Freshwater Planaria. |
title_fullStr |
Cysteine and Aspartyl Proteases Contribute to Protein Digestion in the Gut of Freshwater Planaria. |
title_full_unstemmed |
Cysteine and Aspartyl Proteases Contribute to Protein Digestion in the Gut of Freshwater Planaria. |
title_sort |
cysteine and aspartyl proteases contribute to protein digestion in the gut of freshwater planaria. |
publisher |
Public Library of Science (PLoS) |
publishDate |
2016 |
url |
https://doi.org/10.1371/journal.pntd.0004893 https://doaj.org/article/40ef71f4033643a6bc3c7941a770802a |
geographic |
Arctic |
geographic_facet |
Arctic |
genre |
Arctic |
genre_facet |
Arctic |
op_source |
PLoS Neglected Tropical Diseases, Vol 10, Iss 8, p e0004893 (2016) |
op_relation |
http://europepmc.org/articles/PMC4976874?pdf=render https://doaj.org/toc/1935-2727 https://doaj.org/toc/1935-2735 1935-2727 1935-2735 doi:10.1371/journal.pntd.0004893 https://doaj.org/article/40ef71f4033643a6bc3c7941a770802a |
op_doi |
https://doi.org/10.1371/journal.pntd.0004893 |
container_title |
PLOS Neglected Tropical Diseases |
container_volume |
10 |
container_issue |
8 |
container_start_page |
e0004893 |
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