A Rho-like small GTPase of Entamoeba histolytica contains an unusual amino acid residue in a conserved GDP-stabilization region and is not a substrate for C3 exoenzyme

Godbold, Gene D.; Corbett, K.D.; Mann, Barbara J.

doi:10.1016/s0014-4894(02)00101-7

Cited by 12 publications

(15 citation statements)

References 9 publications

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“…In fact, the corresponding mutation in Hs Cdc42, F28L, can induce cellular transformation in fibroblasts (41). This unique residue has led others to postulate that EhRho1 is constitutively active (21). Two other putative nucleotide-contacting residues in EhRho1 differ from the Rho/Ras consensus, namely, Ser-166 and Val-167.…”

Section: Comparison Of Human and E Histolytica Ras Superfamilymentioning

confidence: 99%

“…Two other putative nucleotide-contacting residues in EhRho1 differ from the Rho/Ras consensus, namely, Ser-166 and Val-167. These sequence features of EhRho1 taken together have suggested a unique mechanism of nucleotide exchange and thus activation (21). To investigate the structural determinants of EhRho1 activation, we obtained high-resolution structural models of EhRho1 in two nucleotide states by x-ray diffraction crystallography.…”

Section: Comparison Of Human and E Histolytica Ras Superfamilymentioning

confidence: 99%

“…S1), EhRho1 serves as an exemplary small G-protein signaling molecule from E. histolytica. Protein sequence and biochemical analyses have suggested divergent guanine nucleotide binding motifs and a resistance to inhibitory ADP-ribosylation by Clostridium botulinum C3 exoenzyme, a hallmark of mammalian Rho GTPases (21). Thus, Godbold et al (21) have suggested that EhRho1 may be a Ras-like GTPase rather than a true functional ortholog of mammalian Rho GTPases.…”

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confidence: 99%

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Unique Structural and Nucleotide Exchange Features of the Rho1 GTPase of Entamoeba histolytica

Bosch

Wittchen

Connie

et al. 2011

Journal of Biological Chemistry

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Background: Rho family GTPases regulate Entamoeba histolytica pathogenesis. Results: Despite Ras-like structural features and fast intrinsic nucleotide exchange, EhRho1 engages classical Rho effectors and regulates actin. Conclusion: EhRho1 is a true Rho family GTPase with a unique mode of nucleotide interaction. Significance: Possibly representing an early Rho subfamily divergence from the Ras superfamily, EhRho1 likely regulates actin polymerization in E. histolytica.

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Section: Comparison Of Human and E Histolytica Ras Superfamilymentioning

confidence: 99%

Section: Comparison Of Human and E Histolytica Ras Superfamilymentioning

confidence: 99%

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confidence: 99%

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Unique Structural and Nucleotide Exchange Features of the Rho1 GTPase of Entamoeba histolytica

Bosch

Wittchen

Connie

et al. 2011

Journal of Biological Chemistry

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“…So far, we do not know whether the toxin receptors are missing or whether the endocytic uptake machinery of Entamoeba histolytica does not allow entry of the toxin. Recently, it was reported that C3 exoenzyme from Clostridium botulinum, which ADP ribosylates mammalian Rho protein at Asn41 (3), is not able to modify EhRho1 (13). In contrast, expression of C3 in intact amoebae caused functional consequences, e.g., cell killing by Entamoeba histolytica was inhibited (14).…”

Section: Discussionmentioning

confidence: 99%

“…Previous studies demonstrate that EhRho1, the Rho-like GTPase from Entamoeba histolytica, is not a substrate of the ADP-ribosylating C3 exoenzyme of Clostridium botulinum (13). However, the expression of C3 in Entamoeba histolytica showed an inhibition of cytolytic activity and monolayer destruction (14).…”

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EhRho1, a RhoA-Like GTPase of Entamoeba histolytica , Is Modified by Clostridial Glucosylating Cytotoxins

Majumder

Schmidt

Lohia

et al. 2006

Appl Environ Microbiol

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Rho signaling in Entamoeba histolytica modulates actomyosin‐dependent activities stimulated during invasive behavior

Franco‐Barraza

Zamudio-Meza

Franco

et al. 2006

Cell Motil. Cytoskeleton

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Interaction of Entamoeba histolytica trophozoites with target cells and substrates activates signaling pathways in the parasite. Phosphorylation cascades triggered by phospho-inositide and adenyl-cyclase-dependent pathways modulate reorganization of the actin cytoskeleton to form structures that facilitate adhesion. In contrast, little is known about participation of Rho proteins and Rho signaling in actin rearrangements. We report here the in vivo expression of at least one Rho protein in trophozoites, whose activation induced actin reorganization and actin-myosin interaction. Antibodies to EhRhoA1 recombinant protein mainly localized Rho in the cytosol of nonactivated amoebae, but it was translocated to vesicular membranes and to some extent to the plasma membrane after treatment with lysophosphatidic acid (LPA), a specific agonist of Rho activation. Activated Rho was identified in LPA-treated trophozoites. LPA induced striking polymerization of actin into distinct dynamic structures. Disorganization of these structures by inhibition of Rho effector, Rho-kinase (ROCK), and by ML-7, an inhibitor of myosin light chain kinase dependent phosphorylation of myosin light chain, suggested that the actin structures also contained myosin. LPA stimulated concanavalin-A-mediated formation of caps, chemotaxis, invasion of extracellular matrix substrates, and erythrophagocytosis, but not binding to fibronectin. ROCK inhibition impaired LPA-stimulated functions and to some extent adhesion to fibronectin. Similar results were obtained with ML-7. These data suggest the presence and operation of Rho-signaling pathways in E. histolytica, that together with other, already described, signaling routes modulate actomyosin-dependent motile processes, particularly stimulated during invasive behavior.

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A Rho-like small GTPase of Entamoeba histolytica contains an unusual amino acid residue in a conserved GDP-stabilization region and is not a substrate for C3 exoenzyme

Cited by 12 publications

References 9 publications

Unique Structural and Nucleotide Exchange Features of the Rho1 GTPase of Entamoeba histolytica

Unique Structural and Nucleotide Exchange Features of the Rho1 GTPase of Entamoeba histolytica

EhRho1, a RhoA-Like GTPase of Entamoeba histolytica , Is Modified by Clostridial Glucosylating Cytotoxins

Rho signaling in Entamoeba histolytica modulates actomyosin‐dependent activities stimulated during invasive behavior

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