A Trypanosoma cruzi phosphatidylinositol 3-kinase (TcVps34) is involved in osmoregulation and receptor-mediated endocytosis
Trypanosoma cruzi, the etiological agent of Chagas disease, has the ability to respond to a variety of environmental changes during its life cycle both in the insect vector and in the vertebrate host. Because regulation of transcription initiation seems to be nonfunctional in this parasite, it is im...
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2008
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| Acceso en línea: | https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00219258_v283_n46_p31541_Schoijet http://hdl.handle.net/20.500.12110/paper_00219258_v283_n46_p31541_Schoijet |
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paper:paper_00219258_v283_n46_p31541_Schoijet2025-07-30T17:25:50Z A Trypanosoma cruzi phosphatidylinositol 3-kinase (TcVps34) is involved in osmoregulation and receptor-mediated endocytosis Cell membranes Chemical reactions Enzyme activity Enzyme inhibition Life cycle Phospholipids Phosphoric acid Signal transduction Chagas diseases Environmental changes Etiological agents Intracellular compartments Membrane trafficking Osmoregulation Overexpressing cells Overexpression Phosphatidylinositol Phosphoinositides Pyrophosphatase Regulation of transcriptions Regulatory mechanisms Regulatory volume decreases Signal transduction pathways Trypanosoma cruzi Vesicular trafficking Wild types Wortmannin Laws and legislation adenosine triphosphatase ly 294000 phosphatidylinositol 3 kinase phosphatidylinositol 3 kinase inhibitor unclassified drug wortmannin acidification article cell migration cell vacuole cell volume cellular distribution cellular stress response endocytosis enzyme assay enzyme inhibition enzyme specificity epimastigote gene overexpression nonhuman nucleotide sequence osmoregulation priority journal protein family protein function protein phosphorylation sequence analysis structural homology survival time tonoplast Trypanosoma cruzi wild type yeast 1-Phosphatidylinositol 3-Kinase Animals Cloning, Molecular Endocytosis Gene Expression Regulation, Enzymologic Inorganic Pyrophosphatase Microscopy, Electron, Scanning Microscopy, Electron, Transmission Molecular Sequence Data Phenotype Protein Kinase Inhibitors Proton-Translocating ATPases Saccharomyces cerevisiae Trypanosoma cruzi Water-Electrolyte Balance Hexapoda Trypanosoma cruzi Vertebrata Trypanosoma cruzi, the etiological agent of Chagas disease, has the ability to respond to a variety of environmental changes during its life cycle both in the insect vector and in the vertebrate host. Because regulation of transcription initiation seems to be nonfunctional in this parasite, it is important to investigate other regulatory mechanisms of adaptation. Regulatory mechanisms at the level of signal transduction pathways involving phosphoinositides are good candidates for this purpose. Here we report the identification of the first phosphatidylinositol 3-kinase (PI3K) in T. cruzi, with similarity with its yeast counterpart, Vps34p. TcVps34 specifically phosphorylates phosphatidylinositol to produce phosphatidylinositol 3-phosphate, thus confirming that it belongs to class III PI3K family. Overexpression of TcVps34 resulted in morphological and functional alterations related to vesicular trafficking. Although inhibition of TcVps34 with specific PI3K inhibitors, such as wortmannin and LY294,000, resulted in reduced regulatory volume decrease after hyposmotic stress, cells overexpressing this enzyme were resistant to these inhibitors. Furthermore, these cells were able to recover their original volume faster than wild type cells when they were submitted to severe hyposmotic stress. In addition, in TcVps34-overexpressing cells, the activities of vacuolar-H+-ATPase and vacuolar H+- pyrophosphatase were altered, suggesting defects in the acidification of intracellular compartments. Furthermore, receptor-mediated endocytosis was partially blocked although fluid phase endocytosis was not affected, confirming a function for TcVps34 in membrane trafficking. Taken together, these results strongly support that TcVps34 plays a prominent role in vital processes for T. cruzi survival such as osmoregulation, acidification, and vesicular trafficking. © 2008 by The American Society for Biochemistry and Molecular Biology, Inc. 2008 https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00219258_v283_n46_p31541_Schoijet http://hdl.handle.net/20.500.12110/paper_00219258_v283_n46_p31541_Schoijet |
| institution |
Universidad de Buenos Aires |
| institution_str |
I-28 |
| repository_str |
R-134 |
| collection |
Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) |
| topic |
Cell membranes Chemical reactions Enzyme activity Enzyme inhibition Life cycle Phospholipids Phosphoric acid Signal transduction Chagas diseases Environmental changes Etiological agents Intracellular compartments Membrane trafficking Osmoregulation Overexpressing cells Overexpression Phosphatidylinositol Phosphoinositides Pyrophosphatase Regulation of transcriptions Regulatory mechanisms Regulatory volume decreases Signal transduction pathways Trypanosoma cruzi Vesicular trafficking Wild types Wortmannin Laws and legislation adenosine triphosphatase ly 294000 phosphatidylinositol 3 kinase phosphatidylinositol 3 kinase inhibitor unclassified drug wortmannin acidification article cell migration cell vacuole cell volume cellular distribution cellular stress response endocytosis enzyme assay enzyme inhibition enzyme specificity epimastigote gene overexpression nonhuman nucleotide sequence osmoregulation priority journal protein family protein function protein phosphorylation sequence analysis structural homology survival time tonoplast Trypanosoma cruzi wild type yeast 1-Phosphatidylinositol 3-Kinase Animals Cloning, Molecular Endocytosis Gene Expression Regulation, Enzymologic Inorganic Pyrophosphatase Microscopy, Electron, Scanning Microscopy, Electron, Transmission Molecular Sequence Data Phenotype Protein Kinase Inhibitors Proton-Translocating ATPases Saccharomyces cerevisiae Trypanosoma cruzi Water-Electrolyte Balance Hexapoda Trypanosoma cruzi Vertebrata |
| spellingShingle |
Cell membranes Chemical reactions Enzyme activity Enzyme inhibition Life cycle Phospholipids Phosphoric acid Signal transduction Chagas diseases Environmental changes Etiological agents Intracellular compartments Membrane trafficking Osmoregulation Overexpressing cells Overexpression Phosphatidylinositol Phosphoinositides Pyrophosphatase Regulation of transcriptions Regulatory mechanisms Regulatory volume decreases Signal transduction pathways Trypanosoma cruzi Vesicular trafficking Wild types Wortmannin Laws and legislation adenosine triphosphatase ly 294000 phosphatidylinositol 3 kinase phosphatidylinositol 3 kinase inhibitor unclassified drug wortmannin acidification article cell migration cell vacuole cell volume cellular distribution cellular stress response endocytosis enzyme assay enzyme inhibition enzyme specificity epimastigote gene overexpression nonhuman nucleotide sequence osmoregulation priority journal protein family protein function protein phosphorylation sequence analysis structural homology survival time tonoplast Trypanosoma cruzi wild type yeast 1-Phosphatidylinositol 3-Kinase Animals Cloning, Molecular Endocytosis Gene Expression Regulation, Enzymologic Inorganic Pyrophosphatase Microscopy, Electron, Scanning Microscopy, Electron, Transmission Molecular Sequence Data Phenotype Protein Kinase Inhibitors Proton-Translocating ATPases Saccharomyces cerevisiae Trypanosoma cruzi Water-Electrolyte Balance Hexapoda Trypanosoma cruzi Vertebrata A Trypanosoma cruzi phosphatidylinositol 3-kinase (TcVps34) is involved in osmoregulation and receptor-mediated endocytosis |
| topic_facet |
Cell membranes Chemical reactions Enzyme activity Enzyme inhibition Life cycle Phospholipids Phosphoric acid Signal transduction Chagas diseases Environmental changes Etiological agents Intracellular compartments Membrane trafficking Osmoregulation Overexpressing cells Overexpression Phosphatidylinositol Phosphoinositides Pyrophosphatase Regulation of transcriptions Regulatory mechanisms Regulatory volume decreases Signal transduction pathways Trypanosoma cruzi Vesicular trafficking Wild types Wortmannin Laws and legislation adenosine triphosphatase ly 294000 phosphatidylinositol 3 kinase phosphatidylinositol 3 kinase inhibitor unclassified drug wortmannin acidification article cell migration cell vacuole cell volume cellular distribution cellular stress response endocytosis enzyme assay enzyme inhibition enzyme specificity epimastigote gene overexpression nonhuman nucleotide sequence osmoregulation priority journal protein family protein function protein phosphorylation sequence analysis structural homology survival time tonoplast Trypanosoma cruzi wild type yeast 1-Phosphatidylinositol 3-Kinase Animals Cloning, Molecular Endocytosis Gene Expression Regulation, Enzymologic Inorganic Pyrophosphatase Microscopy, Electron, Scanning Microscopy, Electron, Transmission Molecular Sequence Data Phenotype Protein Kinase Inhibitors Proton-Translocating ATPases Saccharomyces cerevisiae Trypanosoma cruzi Water-Electrolyte Balance Hexapoda Trypanosoma cruzi Vertebrata |
| description |
Trypanosoma cruzi, the etiological agent of Chagas disease, has the ability to respond to a variety of environmental changes during its life cycle both in the insect vector and in the vertebrate host. Because regulation of transcription initiation seems to be nonfunctional in this parasite, it is important to investigate other regulatory mechanisms of adaptation. Regulatory mechanisms at the level of signal transduction pathways involving phosphoinositides are good candidates for this purpose. Here we report the identification of the first phosphatidylinositol 3-kinase (PI3K) in T. cruzi, with similarity with its yeast counterpart, Vps34p. TcVps34 specifically phosphorylates phosphatidylinositol to produce phosphatidylinositol 3-phosphate, thus confirming that it belongs to class III PI3K family. Overexpression of TcVps34 resulted in morphological and functional alterations related to vesicular trafficking. Although inhibition of TcVps34 with specific PI3K inhibitors, such as wortmannin and LY294,000, resulted in reduced regulatory volume decrease after hyposmotic stress, cells overexpressing this enzyme were resistant to these inhibitors. Furthermore, these cells were able to recover their original volume faster than wild type cells when they were submitted to severe hyposmotic stress. In addition, in TcVps34-overexpressing cells, the activities of vacuolar-H+-ATPase and vacuolar H+- pyrophosphatase were altered, suggesting defects in the acidification of intracellular compartments. Furthermore, receptor-mediated endocytosis was partially blocked although fluid phase endocytosis was not affected, confirming a function for TcVps34 in membrane trafficking. Taken together, these results strongly support that TcVps34 plays a prominent role in vital processes for T. cruzi survival such as osmoregulation, acidification, and vesicular trafficking. © 2008 by The American Society for Biochemistry and Molecular Biology, Inc. |
| title |
A Trypanosoma cruzi phosphatidylinositol 3-kinase (TcVps34) is involved in osmoregulation and receptor-mediated endocytosis |
| title_short |
A Trypanosoma cruzi phosphatidylinositol 3-kinase (TcVps34) is involved in osmoregulation and receptor-mediated endocytosis |
| title_full |
A Trypanosoma cruzi phosphatidylinositol 3-kinase (TcVps34) is involved in osmoregulation and receptor-mediated endocytosis |
| title_fullStr |
A Trypanosoma cruzi phosphatidylinositol 3-kinase (TcVps34) is involved in osmoregulation and receptor-mediated endocytosis |
| title_full_unstemmed |
A Trypanosoma cruzi phosphatidylinositol 3-kinase (TcVps34) is involved in osmoregulation and receptor-mediated endocytosis |
| title_sort |
trypanosoma cruzi phosphatidylinositol 3-kinase (tcvps34) is involved in osmoregulation and receptor-mediated endocytosis |
| publishDate |
2008 |
| url |
https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00219258_v283_n46_p31541_Schoijet http://hdl.handle.net/20.500.12110/paper_00219258_v283_n46_p31541_Schoijet |
| _version_ |
1840321663555600384 |