The identity of organelles in the endomembrane system of any eukaryotic cell critically depends on the correctly localized Rab GTPase, which binds effectors and thus promotes membrane remodeling or fusion. However, it is still unresolved which factors are required and therefore define the localization of the correct fusion machinery. Using SNARE-decorated proteoliposomes that cannot fuse on their own, we now demonstrate that full fusion activity can be achieved by just four soluble factors: a soluble SNARE (Vam7), a guanine nucleotide exchange factor (GEF, Mon1-Ccz1), a Rab-GDP dissociation inhibitor (GDI) complex (prenylated Ypt7-GDI), and a Rab effector complex (HOPS). Our findings reveal that the GEF Mon1-Ccz1 is necessary and sufficient for stabilizing prenylated Ypt7 on membranes. HOPS binding to Ypt7-GTP then drives SNARE-mediated fusion, which is fully GTP-dependent. We conclude that an entire fusion cascade can be controlled by a GEF.
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http://dx.doi.org/10.1074/jbc.M117.812941 | DOI Listing |
Sci Rep
January 2025
Plant Biotechnology, Faculty of Biology, University of Freiburg, Schaenzlestr. 1, 79104, Freiburg, Germany.
Bacterial cell division and plant chloroplast division require selfassembling Filamentous temperature-sensitive Z (FtsZ) proteins. FtsZ proteins are GTPases sharing structural and biochemical similarities with eukaryotic tubulin. In the moss Physcomitrella, the morphology of the FtsZ polymer networks varies between the different FtsZ isoforms.
View Article and Find Full Text PDFMutat Res Genet Toxicol Environ Mutagen
January 2025
Free University of Berlin, Institute of Pharmacy, Pharmacology and Toxicology, Berlin, Germany; BASF SE, Experimental Toxicology and Ecology, Ludwigshafen am Rhein, Germany.
Mutagenicity testing is a component of the hazard assessment of industrial chemicals, biocides, and pesticides. Mutations induced by test substances can be detected by in vitro and in vivo methods that have been adopted as OECD Test Guidelines. One of these in vivo methods is the Transgenic Rodent Assay (TGRA), OECD test guideline no.
View Article and Find Full Text PDFAnn Clin Lab Sci
November 2024
Department of Laboratory Medicine, Linyi People's Hospital, Linyi, Shandong, China
Objective: C-X-C motif chemokine receptor 2 (CXCR2) plays a crucial role in inflammation and immunity, and the involvement of chemokine receptors in the tumor microenvironment is extensively documented. However, the impact of CXCR2 deficiency on the complete transcriptome, including mRNA and ncRNAs, in tumor cells remains unclear.
Methods: In this study, we aimed to identify differentially expressed (DE) messenger RNA (mRNAs), long non-coding RNAs (lncRNAs), and circular RNAs (circRNAs) in CXCR2 knockout HeLa cells through transcriptome sequencing and to construct regulatory networks.
J Fungi (Basel)
January 2025
Department of Pathogenobiology, Jilin University Mycology Research Center, Key Laboratory of Zoonosis Research, Ministry of Education, College of Basic Medical Sciences, Jilin University, Changchun 130021, China.
() is a filamentous fungus that causes invasive aspergillosis in immunocompromised individuals. Regulating fungal growth is crucial for preventing disease development. This study found that deleting the guanine nucleotide exchange factor gene led to slower growth and reduced the fungal burden and mortality of infected mice.
View Article and Find Full Text PDFBiosensors (Basel)
January 2025
Chair of Medical Biotechnology, Faculty of Chemistry, Warsaw University of Technology, Noakowskiego 3, 00-664 Warsaw, Poland.
Since lead can cause severe effects on living organisms' health and life, the regular monitoring of Pb levels in water and soil is of particular significance. Recently, it was shown that lead ions can also be detected using affinity-based biosensors, namely, using aptamers as recognition elements. In most cases, thrombin binding aptamer (TBA) was utilized; however, there are more examples of DNA aptamers which could also serve that purpose.
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