How the endoplasmic reticulum (ER) and Golgi apparatus maintain their morphological functional identity while working in concert to ensure production of biomolecules necessary for cell's survival is a fundamental question plant biology. Here, we isolated characterized an Arabidopsis thaliana mutant that partially accumulates membrane markers soluble secretory marker globular structures composed mass convoluted ER tubules connection with bulk ER. We established aberrant phenotype was due...

Giardia lamblia is a parasitic protozoan that infects wide range of vertebrate hosts including humans. Trophozoites are non-invasive but associate tightly with the enterocyte surface small intestine. This narrow ecological specialization entailed extensive morphological and functional adaptations during host-parasite co-evolution, distinctly polarized array endocytic organelles termed peripheral vacuoles (PVs), which confined to dorsal cortical region exposed gut lumen in close proximity...

Giardia lamblia is an intestinal protozoan parasite required to survive in the environment order be transmitted a new host. To ensure survival, flagellated trophozoites colonizing small intestine differentiate into non-motile environmentally-resistant cysts which are then shed environment. This cell differentiation process called encystation characterized by significant morphological remodeling includes secretion of large amounts cyst wall material. Although much known about transcriptional...

Eukaryotic cells use COPII-coated carriers for endoplasmic reticulum (ER)-to-Golgi protein transport. Selective cargo capture into ER-derived is largely driven by the SEC24 component of COPII coat. The Arabidopsis genome encodes three AtSEC24 genes with overlapping expression profiles but it yet to be established whether proteins have roles in plant growth and development. Taking advantage thaliana as a model system studying gene function vivo, through reciprocal crosses, pollen...

Abstract The genome of the protozoan parasite Giardia lamblia is organized in two diploid nuclei, which has so far precluded complete analysis gene function. Here we use a previously developed Cre/ loxP -based knock-out and selection marker salvage strategy human-derived isolate WB-C6 to eliminate all four copies Cyst-Wall-Protein-1 locus ( CWP1 ). Because these loci are silenced proliferating trophozoites highly expressed only encysting cells, ablation allows functional characterization...

Maize polyamine oxidase (MPAO) is a flavin adenine dinucleotide (FAD)-dependent enzyme that catalyses the oxidation of spermine and spermidine at secondary amino groups. The structure MPAO indicates 30-A long U-shaped tunnel forms catalytic site, with residues Glu62 Glu170 located close to enzyme-bound FAD residue Tyr298 in proximity Lys300, which turn hydrogen-bonded N(5) atom via water molecule (HOH309). To provide insight into role these mechanism reduction, we have performed steady-state...

Giardia lamblia parasitism accounts for the majority of cases parasitic diarrheal disease, making this flagellated eukaryote most successful intestinal parasite worldwide. This organism has undergone secondary reduction/elimination entire organelle systems such as mitochondria and Golgi. However, trophozoite to cyst differentiation (encystation) requires neogenesis Golgi-like secretory organelles named encystation-specific vesicles (ESVs), which traffic, modify partition wall proteins...

Protozoan parasites of the genus Giardia are highly prevalent globally, and infect a wide range vertebrate hosts including humans, with proliferation pathology restricted to small intestine. This narrow ecological specialization entailed extensive structural functional adaptations during host-parasite co-evolution. An example is streamlined mitosomal proteome iron-sulphur protein maturation as only biochemical pathway clearly associated this organelle. Here, we applied techniques in...

Abstract Background Giardia lamblia , a parasitic protist of the Metamonada supergroup, has evolved one most diverged endocytic compartment systems investigated so far. Peripheral compartments, currently known as peripheral vesicles or vacuoles (PVs), perform bulk uptake fluid phase material which is then digested and sorted either to cell cytosol back extracellular space. Results Here, we present quantitative morphological characterization these organelles using volumetric electron...

Abstract Determining signalling pathways that regulate pancreatic regeneration following pancreatitis is critical for implementing therapeutic interventions. In this study we elucidated the molecular mechanisms underlying effects of transforming growth factor‐β ( TGFβ ) in epithelial cells during tissue regeneration. To end, conditionally inactivated receptor II TGFβ‐RII using a Cre– LoxP system under control pancreas transcription factor 1a PTF1a promoter, specific epithelium, and evaluated...

Phosphorylated derivatives of phosphatidylinositol (PIPs) are key membrane lipid residues involved in clathrin-mediated endocytosis (CME). CME relies on PIP species PI(4,5)P2 to mark endocytic sites at the plasma (PM) associated clathrin-coated vesicle (CCV) formation. The highly diverged parasitic protist Giardia lamblia presents disordered and static clathrin assemblies PM invaginations, contacting specialized organelles called peripheral vacuoles (PVs). role for fluid phase uptake their...

The Golgi apparatus is a vital organelle in eukaryotic cells. It grabs and processes secretory materials synthesized by the endoplasmic reticulum (ER) before sorting them to their destination. also receives from vacuoles/lysosomes plasma membrane for further recycling other compartments within cell (1) (Figure 1). Given role of cell, it important understand how this attains maintains its structural functional integrity during intense traffic. Despite an equally central traffic eukaryotes,...

Comparing a parasitic lineage to its free-living relatives is powerful way understand how that evolutionary transition parasitism occurred. Giardia intestinalis (Fornicata) leading cause of gastrointestinal disease world-wide and famous for unusual complement cellular compartments, such as having peripheral vacuoles instead typical endosomal compartments. Endocytosis plays an important role in Giardia's pathogenesis. Endosomal sorting complexes required transport (ESCRT) are...

Functional gene and protein characterizations in parasitic protists are often limited by their genetic tractability. Despite the development of CRISPR-Cas9-derived or inspired approaches for a handful protist parasites, overall tractability these organisms remains limited. The intestinal parasite Giardia lamblia is one such species, with added challenge paucity reliable selection markers. To address this limitation, we tested feasibility using Nourseothricin as an effective agent Giardia....

Abstract Understanding cellular ultrastructure is tightly bound to microscopic resolution and the ability identify individual components at that resolution. Expansion microscopy has revolutionised this topic. Here we present compare two protocols of expansion allow for 4.5-fold mostly isotropic use antibodies, metabolic labelling, DNA stains demarcate regions such as endoplasmic reticulum, nuclei, peripheral endocytic compartments well ventral disc cytoskeleton in Giardia lamblia . We an...