title: Characterization of a Fasciola gigantica protein carrying two DM9 domains reveals cellular relocalization property.
abstract: Even at the present age of whole-organism analysis, e.g., genomics, transcriptomics, and proteomics, the biological roles of many proteins remain unresolved. Classified among the proteins of unknown function is a family of proteins harboring repeats of the DM9 domain, a 60-75 amino acids motif first described in a small number of Drosophila melanogaster proteins. Proteins may carry two or more DM9 domains either in combination with other domains or as their sole constituent. Here we have characterized a 16.8 kDa Fasciola gigantica protein comprising two tandem repeated DM9 domains (FgDM9-1). The protein was located in the parenchyma of the immature and mature parasite and consequently it was not detected in the ES product of the parasite but only in the whole worm extract. Interestingly, extraction with SDS yielded a substantially higher amount of the protein suggesting association with insoluble cell components. In Sf9 insect cells a heterologously expressed EGFP-FgDM9-1 chimera showed cell-wide distribution but relocated to vesicle-like structures in the cytoplasm after stimulating cellular stress by bacteria, heat shock or chloroquine. These structures did not colocalize with the markers of endocytosis/phagocytosis ubiquitin, RAB7, GABARAP. The same behavior was noted for Aedes aegypti PRS1, a homologous mosquito DM9 protein as a positive control while EGFP did not exhibit such relocation in the insect cells. Cross-linking experiments on soluble recombinant FgDM9-1 indicated that the protein can undergo specific oligomerization. It is speculated that proteins carrying the DM9 domain have a role in vesicular transport in flatworms and insects.
authors.affiliation: Graduate Program in Biomedical Sciences, Faculty of Allied Health Sciences, Thammasat University, Pathumthani 12121, Thailand.
authors.forename: Wansika
authors.initials: W
authors.lastname: Phadungsil
authors.affiliation: School of Applied Sciences, RMIT University, Bundoora, Victoria 3083, Australia.
authors.forename: Peter M
authors.initials: PM
authors.lastname: Smooker
authors.affiliation: Department of Biology, Faculty of Science, Mahidol University, Bangkok 10400, Thailand.
authors.forename: Suksiri
authors.initials: S
authors.lastname: Vichasri-Grams
authors.affiliation: Graduate Program in Biomedical Sciences, Faculty of Allied Health Sciences, Thammasat University, Pathumthani 12121, Thailand. Electronic address: rgrams@tu.ac.th.
authors.forename: Rudi
authors.initials: R
authors.lastname: Grams
mesh_terms: D000818:Animals; D002460:Cell Line; D003001:Cloning, Molecular; D004926:Escherichia coli; D005209:Fasciola / Q000254:growth & development / Q000378:metabolism*; D015801:Helminth Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D051379:Mice; D000072417:Protein Domains
chemical_list: D015801:Helminth Proteins
keywords: Cellular stress; DM9 domain; Fasciola gigantica; Parenchyma; Platyhelminthes