Biomaterial Database

An Acanthamoeba castellanii metacaspase associates with the contractile vacuole and functions in osmoregulation. 2013

Entsar Saheb, and Wendy Trzyna, and John Bush

Biology Department, University of Arkansas at Little Rock, 2801 South University Dr., Little Rock, AR 72204-1099, USA. ejsaheb@ualr.edu

Acanthamoeba castellanii is a free-living protozoan. Some strains are opportunistic pathogens. A type-I metacaspase was identified in A. castellanii (Acmcp) and was shown to be expressed through the encystation process. The model organism, Dictyostelium discoideum, has been used here as a model for studying these caspase-like proteins. Separate cell lines expressing a GFP-tagged version of the full length Acmcp protein, as well as a deletion proline region mutant of Acmcp protein (GFP-Acmcp-dpr), have been introduced into D. discoideum. Both mutants affect the cellular metabolism, characterized by an increase in the growth rate. Microscopic imaging revealed an association between Acmcp and the contractile vacuole system in D. discoideum. The treatment of cells with selected inhibitors in different environments added additional support to these findings. This evidence shows that Acmcp plays an important role in contractile vacuole regulation and mediated membrane trafficking in D. discoideum. Additionally, the severe defect in contractile vacuole function in GFP-Acmcp-dpr mutant cells suggests that the proline-rich region in Acmcp has an essential role in binding this protein with other partners to maintain this process. Furthermore, Yeast two-hybrid system identified there are weak interactions of the Dictyostelium contractile vacuolar proteins, including Calmodulin, RabD, Rab11 and vacuolar proton ATPase, with Acmcp protein. Taken together, our findings suggest that A. castellanii metacaspase associate with the contractile vacuole and have an essential role in cell osmoregulation, which contributes to its attractiveness as a possible target for treatment therapies against A. castellanii infection.

UI	MeSH Term	Description	Entries
D007038	Hypotonic Solutions	Solutions that have a lesser osmotic pressure than a reference solution such as blood, plasma, or interstitial fluid.	Solutions, Hypotonic
D008856	Microscopy, Fluorescence	Microscopy of specimens stained with fluorescent dye (usually fluorescein isothiocyanate) or of naturally fluorescent materials, which emit light when exposed to ultraviolet or blue light. Immunofluorescence microscopy utilizes antibodies that are labeled with fluorescent dye.	Fluorescence Microscopy,Immunofluorescence Microscopy,Microscopy, Immunofluorescence,Fluorescence Microscopies,Immunofluorescence Microscopies,Microscopies, Fluorescence,Microscopies, Immunofluorescence
D011500	Protein Synthesis Inhibitors	Compounds which inhibit the synthesis of proteins. They are usually ANTI-BACTERIAL AGENTS or toxins. Mechanism of the action of inhibition includes the interruption of peptide-chain elongation, the blocking the A site of ribosomes, the misreading of the genetic code or the prevention of the attachment of oligosaccharide side chains to glycoproteins.	Protein Synthesis Antagonist,Protein Synthesis Antagonists,Protein Synthesis Inhibitor,Antagonist, Protein Synthesis,Antagonists, Protein Synthesis,Inhibitor, Protein Synthesis,Inhibitors, Protein Synthesis,Synthesis Antagonist, Protein,Synthesis Inhibitor, Protein
D004791	Enzyme Inhibitors	Compounds or agents that combine with an enzyme in such a manner as to prevent the normal substrate-enzyme combination and the catalytic reaction.	Enzyme Inhibitor,Inhibitor, Enzyme,Inhibitors, Enzyme
D014617	Vacuoles	Any spaces or cavities within a cell. They may function in digestion, storage, secretion, or excretion.	Vacuole
D014882	Water-Electrolyte Balance	The balance of fluid in the BODY FLUID COMPARTMENTS; total BODY WATER; BLOOD VOLUME; EXTRACELLULAR SPACE; INTRACELLULAR SPACE, maintained by processes in the body that regulate the intake and excretion of WATER and ELECTROLYTES, particularly SODIUM and POTASSIUM.	Fluid Balance,Electrolyte Balance,Balance, Electrolyte,Balance, Fluid,Balance, Water-Electrolyte,Water Electrolyte Balance
D015971	Gene Expression Regulation, Enzymologic	Any of the processes by which nuclear, cytoplasmic, or intercellular factors influence the differential control of gene action in enzyme synthesis.	Enzymologic Gene Expression Regulation,Regulation of Gene Expression, Enzymologic,Regulation, Gene Expression, Enzymologic
D048248	Acanthamoeba castellanii	A species of free-living soil amoebae in the family Acanthamoebidae. It can cause ENCEPHALITIS and KERATITIS in humans.	Acanthamoeba castellanius,castellanius, Acanthamoeba
D049408	Luminescent Agents	Compound such as LUMINESCENT PROTEINS that cause or emit light (PHYSICAL LUMINESCENCE).	Phosphorescent Agents,Agents, Luminescent,Agents, Phosphorescent
D049452	Green Fluorescent Proteins	Protein analogs and derivatives of the Aequorea victoria green fluorescent protein that emit light (FLUORESCENCE) when excited with ULTRAVIOLET RAYS. They are used in REPORTER GENES in doing GENETIC TECHNIQUES. Numerous mutants have been made to emit other colors or be sensitive to pH.	Green Fluorescent Protein,Green-Fluorescent Protein,Green-Fluorescent Proteins,Fluorescent Protein, Green,Fluorescent Proteins, Green,Protein, Green Fluorescent,Protein, Green-Fluorescent,Proteins, Green Fluorescent,Proteins, Green-Fluorescent