Shane Denecke, Madeline F Malfara, Kelly R Hodges, Nikki A Holmes, Andre R Williams, Julia H Gallagher-Teske, Julia M Pascarella, Abigail M Daniels, Geert Jan Sterk, Rob Leurs, Gordon Ruthel, Rachel Hoang, Megan L Povelones, Michael Povelones
{"title":"束带栉水母的粘附促进了由 cAMP 信号驱动的发育命运的快速改变。","authors":"Shane Denecke, Madeline F Malfara, Kelly R Hodges, Nikki A Holmes, Andre R Williams, Julia H Gallagher-Teske, Julia M Pascarella, Abigail M Daniels, Geert Jan Sterk, Rob Leurs, Gordon Ruthel, Rachel Hoang, Megan L Povelones, Michael Povelones","doi":"10.1128/msphere.00617-24","DOIUrl":null,"url":null,"abstract":"<p><p>Trypanosomatids are single-celled parasites responsible for human and animal disease. Typically, colonization of an insect host is required for transmission. Stable attachment of parasites to insect tissues <i>via</i> their single flagellum coincides with differentiation and morphological changes. Although attachment is a conserved stage in trypanosomatid life cycles, the molecular mechanisms are not well understood. To study this process, we elaborate upon an <i>in vitro</i> model in which the swimming form of the trypanosomatid <i>Crithidia fasciculata</i> rapidly differentiates following adhesion to artificial substrates. Live imaging of cells transitioning from swimming to attached shows parasites undergoing a defined sequence of events, including an initial adhesion near the base of the flagellum immediately followed by flagellar shortening, cell rounding, and the formation of a hemidesmosome-like attachment plaque between the tip of the shortened flagellum and the substrate. Quantitative proteomics of swimming versus attached parasites suggests differential regulation of cyclic adenosine monophosphate (cAMP)-based signaling proteins. We have localized two of these proteins to the flagellum of swimming <i>C. fasciculata</i>; however, both are absent from the shortened flagellum of attached cells. Pharmacological inhibition of cAMP phosphodiesterases increased cAMP levels in the cell and prevented attachment. Further, treatment with inhibitor did not affect the growth rate of either swimming or established attached cells, indicating that its effect is limited to a critical window during the early stages of adhesion. These data suggest that cAMP signaling is required for attachment of <i>C. fasciculata</i> and that flagellar signaling domains may be reorganized during differentiation and attachment.IMPORTANCETrypanosomatid parasites cause significant disease burden worldwide and require insect vectors for transmission. In the insect, parasites attach to tissues, sometimes dividing as attached cells or producing motile, infectious forms. The significance and cellular mechanisms of attachment are relatively unexplored. Here, we exploit a model trypanosomatid that attaches robustly to artificial surfaces to better understand this process. This attachment recapitulates that observed <i>in vivo</i> and can be used to define the stages and morphological features of attachment as well as conditions that impact attachment efficiency. We have identified proteins that are enriched in either swimming or attached parasites, supporting a role for the cyclic AMP signaling pathway in the transition from swimming to attached. As this pathway has already been implicated in environmental sensing and developmental transitions in trypanosomatids, our data provide new insights into activities required for parasite survival in their insect hosts.</p>","PeriodicalId":19052,"journal":{"name":"mSphere","volume":null,"pages":null},"PeriodicalIF":3.7000,"publicationDate":"2024-10-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11520290/pdf/","citationCount":"0","resultStr":"{\"title\":\"Adhesion of <i>Crithidia fasciculata</i> promotes a rapid change in developmental fate driven by cAMP signaling.\",\"authors\":\"Shane Denecke, Madeline F Malfara, Kelly R Hodges, Nikki A Holmes, Andre R Williams, Julia H Gallagher-Teske, Julia M Pascarella, Abigail M Daniels, Geert Jan Sterk, Rob Leurs, Gordon Ruthel, Rachel Hoang, Megan L Povelones, Michael Povelones\",\"doi\":\"10.1128/msphere.00617-24\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<p><p>Trypanosomatids are single-celled parasites responsible for human and animal disease. Typically, colonization of an insect host is required for transmission. Stable attachment of parasites to insect tissues <i>via</i> their single flagellum coincides with differentiation and morphological changes. Although attachment is a conserved stage in trypanosomatid life cycles, the molecular mechanisms are not well understood. To study this process, we elaborate upon an <i>in vitro</i> model in which the swimming form of the trypanosomatid <i>Crithidia fasciculata</i> rapidly differentiates following adhesion to artificial substrates. Live imaging of cells transitioning from swimming to attached shows parasites undergoing a defined sequence of events, including an initial adhesion near the base of the flagellum immediately followed by flagellar shortening, cell rounding, and the formation of a hemidesmosome-like attachment plaque between the tip of the shortened flagellum and the substrate. Quantitative proteomics of swimming versus attached parasites suggests differential regulation of cyclic adenosine monophosphate (cAMP)-based signaling proteins. We have localized two of these proteins to the flagellum of swimming <i>C. fasciculata</i>; however, both are absent from the shortened flagellum of attached cells. Pharmacological inhibition of cAMP phosphodiesterases increased cAMP levels in the cell and prevented attachment. Further, treatment with inhibitor did not affect the growth rate of either swimming or established attached cells, indicating that its effect is limited to a critical window during the early stages of adhesion. These data suggest that cAMP signaling is required for attachment of <i>C. fasciculata</i> and that flagellar signaling domains may be reorganized during differentiation and attachment.IMPORTANCETrypanosomatid parasites cause significant disease burden worldwide and require insect vectors for transmission. In the insect, parasites attach to tissues, sometimes dividing as attached cells or producing motile, infectious forms. The significance and cellular mechanisms of attachment are relatively unexplored. Here, we exploit a model trypanosomatid that attaches robustly to artificial surfaces to better understand this process. This attachment recapitulates that observed <i>in vivo</i> and can be used to define the stages and morphological features of attachment as well as conditions that impact attachment efficiency. We have identified proteins that are enriched in either swimming or attached parasites, supporting a role for the cyclic AMP signaling pathway in the transition from swimming to attached. 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Adhesion of Crithidia fasciculata promotes a rapid change in developmental fate driven by cAMP signaling.
Trypanosomatids are single-celled parasites responsible for human and animal disease. Typically, colonization of an insect host is required for transmission. Stable attachment of parasites to insect tissues via their single flagellum coincides with differentiation and morphological changes. Although attachment is a conserved stage in trypanosomatid life cycles, the molecular mechanisms are not well understood. To study this process, we elaborate upon an in vitro model in which the swimming form of the trypanosomatid Crithidia fasciculata rapidly differentiates following adhesion to artificial substrates. Live imaging of cells transitioning from swimming to attached shows parasites undergoing a defined sequence of events, including an initial adhesion near the base of the flagellum immediately followed by flagellar shortening, cell rounding, and the formation of a hemidesmosome-like attachment plaque between the tip of the shortened flagellum and the substrate. Quantitative proteomics of swimming versus attached parasites suggests differential regulation of cyclic adenosine monophosphate (cAMP)-based signaling proteins. We have localized two of these proteins to the flagellum of swimming C. fasciculata; however, both are absent from the shortened flagellum of attached cells. Pharmacological inhibition of cAMP phosphodiesterases increased cAMP levels in the cell and prevented attachment. Further, treatment with inhibitor did not affect the growth rate of either swimming or established attached cells, indicating that its effect is limited to a critical window during the early stages of adhesion. These data suggest that cAMP signaling is required for attachment of C. fasciculata and that flagellar signaling domains may be reorganized during differentiation and attachment.IMPORTANCETrypanosomatid parasites cause significant disease burden worldwide and require insect vectors for transmission. In the insect, parasites attach to tissues, sometimes dividing as attached cells or producing motile, infectious forms. The significance and cellular mechanisms of attachment are relatively unexplored. Here, we exploit a model trypanosomatid that attaches robustly to artificial surfaces to better understand this process. This attachment recapitulates that observed in vivo and can be used to define the stages and morphological features of attachment as well as conditions that impact attachment efficiency. We have identified proteins that are enriched in either swimming or attached parasites, supporting a role for the cyclic AMP signaling pathway in the transition from swimming to attached. As this pathway has already been implicated in environmental sensing and developmental transitions in trypanosomatids, our data provide new insights into activities required for parasite survival in their insect hosts.
期刊介绍:
mSphere™ is a multi-disciplinary open-access journal that will focus on rapid publication of fundamental contributions to our understanding of microbiology. Its scope will reflect the immense range of fields within the microbial sciences, creating new opportunities for researchers to share findings that are transforming our understanding of human health and disease, ecosystems, neuroscience, agriculture, energy production, climate change, evolution, biogeochemical cycling, and food and drug production. Submissions will be encouraged of all high-quality work that makes fundamental contributions to our understanding of microbiology. mSphere™ will provide streamlined decisions, while carrying on ASM''s tradition for rigorous peer review.