A potential role for Giardia chaperone protein GdDnaJ in regulating Giardia proliferation and Giardiavirus replication.

BACKGROUND: Giardia duodenalis (referred to as Giardia) is a flagellated binucleate protozoan parasite, which causes one of the most common diarrheal diseases, giardiasis, worldwide. Giardia can be infected by Giardiavirus (GLV), a small endosymbiotic dsRNA virus belongs to the Totiviridae family. However, the regulation of GLV and a positive correlation between GLV and Giardia virulence is yet to be elucidated. METHODS: To identify potential regulators of GLV, we performed a yeast two-hybrid (Y2H) screen to search for interacting proteins of RdRp. GST pull-down, co-immunoprecipitation and bimolecular fluorescence complementation (BiFC) assay were used to verify the direct physical interaction between GLV RdRp and its new binding partner. In addition, their in vivo interaction and colocalization in Giardia trophozoites were examined by using Duolink proximal ligation assay (Duolink PLA). RESULTS: From Y2H screen, the Giardia chaperone protein, Giardia DnaJ (GdDnaJ), was identified as a new binding partner for GLV RdRp. The direct interaction between GdDnaJ and GLV RdRp was verified via GST pull-down, co-immunoprecipitation and BiFC. In addition, colocalization and in vivo interaction between GdDnaJ and RdRp in Giardia trophozoites were confirmed by Duolink PLA. Further analysis revealed that KNK437, the inhibitor of GdDnaJ, can significantly reduce the replication of GLVs and the proliferation of Giardia. CONCLUSION: Taken together, our results suggested a potential role of GdDnaJ in regulating Giardia proliferation and GLV replication through interaction with GLV RdRp.

[Characteristics, Sources, and Risk Assessment of Perlyfluoroalkyl Substances in Surface Water and Sediment of Luoma Lake].

Through the investigation and detection of the surface water and sediments of Luoma Lake, the structure and occurrence characteristics of PFASs (perlyfluoroalkyl substances) in the two types of media were analyzed, and the principal component analysis method was used to analyze the characteristics of such substances in the surface water. The source was analyzed, and the potential health risks of such substances were evaluated using the risk quotient method. The results showed that a total of 13 PFASs were detected in the surface sediments of Luoma Lake, and one more species was detected in the surface water (PFTeA); ρ(ΣPFASs) in the surface water ranged from 46.09 to 120.34 ng·L-1, and ω(ΣPFASs) in sediments ranged from 2.22 to 9.55 ng·g-1. PFPeA was the major component in surface water, and the mass fraction of PFPeA was 38%. PFBA was the major component in sediment, and the mass fraction of PFPeA was 61%. The multi-media PFASs in Luoma Lake were mainly short-chain substances; the high concentration area of PFASs in the surface water of Luoma Lake was concentrated and distributed at the mouth of the northern rivers. Its concentration showed a decreasing trend from north to south, and the content of PFASs in the sediments showed a decreasing trend from southwest to northeast. The distribution of ΣPFASs, PFBA, and PFOS in the sediments of Luoma Lake and the TOC content in the sediment were related; the principal component analysis showed that the PFASs in the surface water of Luoma Lake were mainly from textile flame retardant, rubber product emulsification, food packaging processes and paper surface treatment industries, the metal electroplating industry, and leather and textile manufacturing industries. PFASs in the surface water of Luoma Lake were at a relatively low health risk level.