TcRho1 of Trypanosoma cruzi: role in metacyclogenesis and cellular localization

Melo, Luiz Dione Barbosa de; Nepomuceno-Silva, José Luciano; Sant’Anna, Celso; Eisele, Nicole; Ferraro, Rodrigo B.; Meyer‐Fernandes, José Roberto; Souza, Wanderley de; Cunha-e-Silva, Narcisa L.; Lopes, Ulisses Gazos

doi:10.1016/j.bbrc.2004.08.197

Cited by 14 publications

(6 citation statements)

References 32 publications

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“…These data also suggest divergence in functionality between the trypanosomes and Leishmania . Further, this confirms distinct Rho configurations for T. cruzi , T. brucei and L. major , where TcRho has clear conserved Rho-like functions [17]. Significantly, restriction of a true Rho to T. cruzi suggests secondary loss from African trypanosomes and Leishmania .…”

Section: Resultssupporting

confidence: 62%

“…The first of these, TcRho1, has been partly characterized and, together with a function in life cycle progression and differentiation, evidence from heterologous expression suggests that TcRho1 can interact with the mammalian actin cytoskeleton in cell adhesion and migration assays; hence TcRho1 is likely a true Rho protein [16], [17], [18]). The role in metacyclogenesis may also reflect a function in cytoskeletal and morphological remodeling, consistent with classical Rho functionality.…”

Section: Introductionmentioning

confidence: 99%

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A Novel Rho-Like Protein TbRHP Is Involved in Spindle Formation and Mitosis in Trypanosomes

et al. 2011

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BackgroundIn animals and fungi Rho subfamily small GTPases are involved in signal transduction, cytoskeletal function and cellular proliferation. These organisms typically possess multiple Rho paralogues and numerous downstream effectors, consistent with the highly complex contributions of Rho proteins to cellular physiology. By contrast, trypanosomatids have a much simpler Rho-signaling system, and the Trypanosoma brucei genome contains only a single divergent Rho-related gene, TbRHP (Tb927.10.6240). Further, only a single RhoGAP-like protein (Tb09.160.4180) is annotated, contrasting with the >70 Rho GAP proteins from Homo sapiens. We wished to establish the function(s) of TbRHP and if Tb09.160.4180 is a potential GAP for this protein.Methods/FindingsTbRHP represents an evolutionarily restricted member of the Rho GTPase clade and is likely trypanosomatid restricted. TbRHP is expressed in both mammalian and insect dwelling stages of T. brucei and presents with a diffuse cytoplasmic location and is excluded from the nucleus. RNAi ablation of TbRHP results in major cell cycle defects and accumulation of multi-nucleated cells, coinciding with a loss of detectable mitotic spindles. Using yeast two hybrid analysis we find that TbRHP interacts with both Tb11.01.3180 (TbRACK), a homolog of Rho-kinase, and the sole trypanosome RhoGAP protein Tb09.160.4180, which is related to human OCRL.ConclusionsDespite minimization of the Rho pathway, TbRHP retains an important role in spindle formation, and hence mitosis, in trypanosomes. TbRHP is a partner for TbRACK and an OCRL-related trypanosome Rho-GAP.

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Section: Resultssupporting

confidence: 62%

Section: Introductionmentioning

confidence: 99%

A Novel Rho-Like Protein TbRHP Is Involved in Spindle Formation and Mitosis in Trypanosomes

et al. 2011

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“…Attempts to characterize and localize protein markers of intracellular compartments, e.g. Rab5, Rab7, Rab11 and Rho1, were unsuccessful and/or not fully explored [53-56]. We found that during nutritional stress GP82 and GP90 accumulate in distinct compartments in intermediate forms, despite their localization on the cell surface of metacyclic forms, indicating the existence of different control mechanisms to access the cell surface.…”

Section: Discussionmentioning

confidence: 92%

Expression and cellular trafficking of GP82 and GP90 glycoproteins during Trypanosoma cruzi metacyclogenesis

et al. 2013

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BackgroundThe transformation of noninfective epimastigotes into infective metacyclic trypomastigotes (metacyclogenesis) is a fundamental step in the life cycle of Trypanosoma cruzi, comprising several morphological and biochemical changes. GP82 and GP90 are glycoproteins expressed at the surface of metacyclic trypomastigote, with opposite roles in mammalian cell invasion. GP82 is an adhesin that promotes cell invasion, while GP90 acts as a negative regulator of parasite internalization. Our understanding of the synthesis and intracellular trafficking of GP82 and GP90 during metacyclogenesis is still limited. Therefore, we decided to determine whether GP82 and GP90 are expressed only in fully differentiated metacyclic forms or they start to be expressed in intermediate forms undergoing differentiation.MethodsParasite populations enriched in intermediate forms undergoing differentiation were analyzed by quantitative real-time PCR, Western blot, flow cytometry and immunofluorescence to assess GP82 and GP90 expression.ResultsWe found that GP82 and GP90 mRNAs and proteins are expressed in intermediate forms and reach higher levels in fully differentiated metacyclic forms. Surprisingly, GP82 and GP90 presented distinct cellular localizations in intermediate forms compared to metacyclic trypomastigotes. In intermediate forms, GP82 is localized in organelles at the posterior region and colocalizes with cruzipain, while GP90 is localized at the flagellar pocket region.ConclusionsThis study discloses new aspects of protein expression and trafficking during T. cruzi differentiation by showing that the machinery involved in GP82 and GP90 gene expression starts to operate early in the differentiation process and that different secretion pathways are responsible for delivering these glycoproteins toward the cell surface.

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“…2B), was inhibited by CAAX mimetics and FPP analogs, with 50% inhibitory concentrations ranging from 10 to 50 M. In contrast, T. cruzi epimastigotes were resistant to 50 to 100 M PFT inhibitors (37). In addition to TcPRL-1, the only other protein that has been shown to be farnesylated in T. cruzi is TcRho 1, which is a small GTPase possibly involved in signal transduction and metacyclogenesis (8,23). The identification of farnesylated proteins in T. cruzi will help to identify the mechanism of toxicity of isoprenoid synthesis and protein farnesylation inhibitors.…”

Section: Vol 4 2005mentioning

confidence: 99%

Characterization of Farnesylated Protein Tyrosine Phosphatase TcPRL-1 from Trypanosoma cruzi

et al. 2005

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Protein tyrosine kinases and phosphatases play important roles in the regulation of cell growth, development, and differentiation. We report here the identification in Trypanosoma cruzi of a gene (TcPRL-1) encoding a protein tyrosine phosphatase. The predicted protein (TcPRL-1) shares ca. 35% identity with the mammalian protein tyrosine phosphatase known as phosphatase of regenerating liver 1 (PRL-1). Four copies of this protein tyrosine phosphatase are present in the T. cruzi genome, and Northern blot assays showed a transcript of ϳ750 bases. TcPRL-1 was detected by Western blot analysis only in amastigote extracts as a 21-kDa protein.TcPRL-1 was expressed in Escherichia coli, and its phosphatase activity was determined by using p-nitrophenylphosphate and a phosphorylated protein as substrates. In contrast to other PRLs, TcPRL-1 activity was not affected by pentamidine, and it was inhibited by very low concentrations of o-vanadate. TcPRL-1 has a C-terminal CAAX motif (CAVM) and is farnesylated in vitro by T. cruzi epimastigote extracts and in vivo according to the transfection results. After transfection of T. cruzi with a vector that expresses TcPRL-1 as a C-terminal fusion to green fluorescent protein, GFP-TcPRL-1 was detected in the endocytic pathway of epimastigotes, amastigotes, and trypomastigotes by colocalization with cruzipain and concanavalin A. Interestingly, a mutant form without the CAAX motif localized to the cytoplasm, in contrast to its mammalian counterparts that localize to the nucleus. The results of these studies on TcPRL-1 reveal that, even though the animal and parasite PRLs share similar kinetic properties, their susceptibilities to inhibitors, as well as their localization, are distinct, implying that they may be involved in different cellular processes.Phosphorylation of proteins in specific tyrosyl residues is a major control mechanism for several processes such as normal cell growth, differentiation, metabolism, cell cycle, cell migration, and gene expression, among others (16). The levels of cellular protein phosphorylation in tyrosine residues are controlled by the activities of both protein tyrosine kinases and phosphatases. Although protein tyrosine phosphatases (PTPs) were initially believed to have housekeeping roles, it is now obvious that they are highly regulated and specific enzymes (33).PTPs form a large superfamily of enzymes with more than 100 members. The hallmark that defines the PTP superfamily is the presence of the signature motif (or active site), HCX 2 GX 2 R in the catalytic domain. PTPs can be divided according to their sequence homology and substrate specificity in tyrosine-specific phosphatases and dual-specific phosphatases. The latter class of phosphatases are the only that cleave phosphoester bonds in proteins that contain phosphotyrosine (pTyr), as well as phosphoserine and phosphothreonine.The phosphatase of regenerating liver (PRL) phosphatases represents a new class of PTP. These phosphatases, in mammals, belong to a family composed by at least three mem...

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TcRho1 of Trypanosoma cruzi: role in metacyclogenesis and cellular localization

Cited by 14 publications

References 32 publications

A Novel Rho-Like Protein TbRHP Is Involved in Spindle Formation and Mitosis in Trypanosomes

A Novel Rho-Like Protein TbRHP Is Involved in Spindle Formation and Mitosis in Trypanosomes

Expression and cellular trafficking of GP82 and GP90 glycoproteins during Trypanosoma cruzi metacyclogenesis

Characterization of Farnesylated Protein Tyrosine Phosphatase TcPRL-1 from Trypanosoma cruzi

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