Disease relevance of Acanthamoeba

• This 'Arp2/3 complex' has been identified in Acanthamoeba and human cells and has been shown to localize to regions involved in actin-based motility, such as the leading edge of moving cells and the 'tail' of actin that forms behind the intracellular pathogen Listeria [1].
• To determine the effects, if any, of the Zn-metalloprotease on virulence of Legionella pneumophila infection, an isogenic mutant deficient in protease (encoded by the proA gene) was tested in an Acanthamoeba cell model, in guinea-pig macrophages, and in a guinea-pig pneumonia model [2].
• A 57-year-old chronically immunosuppressed woman with systemic lupus erythematosus developed fulminant meningoencephalitis due to Acanthamoeba castellanii [3].
• Corynebacterium xerosis, a constituent of the ocular flora, contains large amounts of mannose and is associated with Acanthamoeba keratitis [4].
• CONCLUSIONS: Polyhexamethylene biguanide is effective against both Acanthamoeba and Nocardia and may have a wider range of usefulness than that currently recognized [5].

Psychiatry related information on Acanthamoeba

• Defense mechanisms of IFN-gamma and LPS-primed murine microglia against Acanthamoeba castellanii infection [6].

High impact information on Acanthamoeba

• We have cloned the chickadee gene and found that cDNA clones encode a protein 40% identical to yeast and Acanthamoeba profilin [7].
• Study of mutated yeast profilins and profilins from Acanthamoeba suggests that the ability of profilin to suppress cap- cells is dependent upon a property other than, or in addition to, its ability to bind actin [8].
• Forms of RNA polymerase I prepared from growing or encysted Acanthamoeba are equal in the ability to transcribe poly(dl:dC) [9].
• We describe the mechanical properties of a model system consisting of actin filaments and Acanthamoeba alpha-actinin, one of several actin crosslinking proteins found in amoeba and other cells [10].
• Electron cryomicroscopy and three-dimensional reconstruction of Acanthamoeba castellanii and Saccharomyces cerevisiae Arp2/3 complexes bound to the WASp carboxy-terminal domain reveal asymmetric, oblate ellipsoids [11].

Chemical compound and disease context of Acanthamoeba

• The first medical cure of Acanthamoeba keratitis was obtained by use of propamidine isethionate [12].
• Therefore, the neuraminidase of Acanthamoeba species could be relevant in the colonization and damage of the sialic acid-rich corneal epithelium and in the alterations of glycolipids associated with meningoencephalitis [13].
• Treatment of acanthamoeba keratitis with chlorhexidine [14].
• Treatment of Acanthamoeba keratitis with polyhexamethylene biguanide [15].
• Our observations could result in significant improvement in the efficacy of H(2)O(2) contact lens disinfection systems against Acanthamoeba cysts and prevention of acanthamoeba keratitis [16].

Biological context of Acanthamoeba

• Mechanism of action of Acanthamoeba profilin: demonstration of actin species specificity and regulation by micromolar concentrations of MgCl2 [17].
• p21-activated kinase has substrate specificity similar to Acanthamoeba myosin I heavy chain kinase and activates Acanthamoeba myosin I [18].
• To investigate whether transcripts from foreign split genes are correctly processed in yeast cells we have constructed two hybrid genes by inserting into the split yeast actin gene an intron-containing fragment from either the Acanthamoeba actin I gene or the duck alpha D-globin gene [19].
• The actin-activated Mg2+-ATPase activity of myosin II from the soil amoeba Acanthamoeba castellanii is regulated by phosphorylation of 3 serine residues on the myosin II heavy chain [20].
• We have used the substrate [5,6-3H]UTP for direct photoaffinity labeling of the active site of the heavy chain of myosin II from Acanthamoeba castellanii [21].

Anatomical context of Acanthamoeba

• If other actin-filament crosslinking proteins behave like Acanthamoeba alpha-actinin, this mechanism may explain how the cortex recoils elastically from small rapid insults but deforms extensively when minute forces are applied over long periods of time [10].
• In addition, F-actin bundles were obtained with chicken gizzard and Acanthamoeba alpha-actinin, but not Dictyostelium alpha-actinin under conditions where actin by itself polymerized into disperse filaments [22].
• Electron partitioning between the two branching quinol-oxidizing pathways in Acanthamoeba castellanii mitochondria during steady-state state 3 respiration [23].
• The Acanthamoeba chimera forms short bipolar filaments similar to, but shorter than, filaments of Dictyostelium myosin and the smooth muscle chimera forms much larger side-polar filaments [24].
• TPBF does not have a counterpart in HeLa cells, but nonetheless strongly stimulates transcription of the Acanthamoeba TBP gene in mammalian extracts [25].

Associations of Acanthamoeba with chemical compounds

• The actin-activated Mg(2+)-ATPase activities of Acanthamoeba myosins I are known to be maximally expressed only when a single threonine (myosin IA) or serine (myosins IB and IC) is phosphorylated by myosin I heavy chain kinase [26].
• Identification of functional regions on the tail of Acanthamoeba myosin-II using recombinant fusion proteins. II. Assembly properties of tails with NH2- and COOH-terminal deletions [27].
• Two Triton-insoluble fractions were isolated from Acanthamoeba castellanii [28].
• Isolation and electrophoretic analysis of nucleoli, phenol-soluble nuclear proteins, and outer cyst walls from Acanthamoeba castellanii during encystation initiation [29].
• Profilins bind to monomeric actin and also interact with ligands such as phosphoinositide 4,5-bisphosphate, the proline-rich protein VASP and a complex of four to six polypeptides identified in Acanthamoeba that includes two actin-related proteins [30].

Gene context of Acanthamoeba

• A synthetic peptide was made homologous to amino acid residues 984-996 (HL-33) of the EGFR which shows high homology with the actin-binding domain of Acanthamoeba profilin [31].
• We have investigated the expression of a continuous open reading frame (ORF) present in the mitochondrial genome of Acanthamoeba castellanii and specifying the two largest subunits (COX1 and COX2) of the cytochrome c oxidase complex [32].
• The yield of Acanthamoeba profilin is twice that obtained by conventional methods [33].
• We have identified an unconventional myosin gene (MYO3) in the yeast Saccharomyces cerevisiae and show that it is member of a subclass of unconventional myosin proteins originally found only in the amoeboid organisms Dictyostelium and Acanthamoeba [34].
• Purified recombinant cytokines including tumor necrosis factor alpha, interleukin 1 alpha, and interleukin 1 beta, alone or in combination, were not cytolytic for Acanthamoeba trophozoites [35].

Analytical, diagnostic and therapeutic context of Acanthamoeba

• The Arp2/3 complex, first isolated from Acanthamoeba castellani by affinity chromatography on profilin, consists of seven polypeptides; two actin-related proteins, Arp2 and Arp3; and five apparently novel proteins, p40, p35, p19, p18, and p14 (Machesky et al., 1994) [36].
• We determined the structures of Acanthamoeba profilin I and profilin II by x-ray crystallography at resolutions of 2.0 and 2.8 A, respectively [37].
• Enhanced attachment of acanthamoeba to extended-wear silicone hydrogel contact lenses: a new risk factor for infection [38]?
• Antibodies AMEC1, MTAC3, MTAC4 and MTAC5 reacted with buffered formalin-fixed AC112 by immunohistochemistry, and also stained Acanthamoeba in sections of infected rat cornea and buffered formalin-fixed, paraffin-embedded infected human cornea [39].
• Reverse transcription PCR experiments showed clear lepB expression when L. pneumophila was grown both in culture medium, and also intracellularly in Acanthamoeba castellanii, a natural eukaryotic host of L. pneumophila [40].

References