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Szakadáti G, Tóth AD, Oláh I, Erdélyi LS, Balla T, Várnai P, Hunyady L, Balla A. Investigation of the fate of type I angiotensin receptor after biased activation. Mol Pharmacol 2015; 87:972-81. [PMID: 25804845 DOI: 10.1124/mol.114.097030] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2014] [Accepted: 03/24/2015] [Indexed: 01/14/2023] Open
Abstract
Biased agonism on the type I angiotensin receptor (AT1-R) can achieve different outcomes via activation of G protein-dependent and -independent cellular responses. In this study, we investigated whether the biased activation of AT1-R can lead to different regulation and intracellular processing of the receptor. We analyzed β-arrestin binding, endocytosis, and subsequent trafficking steps, such as early and late phases of recycling of AT1-R in human embryonic kidney 293 cells expressing wild-type or biased mutant receptors in response to different ligands. We used Renilla luciferase-tagged receptors and yellow fluorescent protein-tagged β-arrestin2, Rab5, Rab7, and Rab11 proteins in bioluminescence resonance energy transfer measurements to follow the fate of the receptor after stimulation. We found that not only is the signaling of the receptor different upon using selective ligands, but the fate within the cells is also determined by the type of the stimulation. β-arrestin binding and the internalization kinetics of the angiotensin II-stimulated AT1-R differed from those stimulated by the biased agonists. Similarly, angiotensin II-stimulated wild-type AT1-R showed differences compared with a biased mutant AT1-R (DRY/AAY AT1-R) with regards to β-arrestin binding and endocytosis. We found that the differences in the internalization kinetics of the receptor in response to biased agonist stimulation are due to the differences in plasma membrane phosphatidylinositol 4,5-bisphosphate depletion. Moreover, the stability of the β-arrestin binding is a major determinant of the later fate of the internalized AT1-R receptor.
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Affiliation(s)
- Gyöngyi Szakadáti
- Department of Physiology, Semmelweis University, Faculty of Medicine, Budapest, Hungary (G.S., A.D.T., I.O., L.S.E., P.V., L.H., A.B.), Magyar Tudományos Akadémia-Semmelweis Egyetem Laboratory of Molecular Physiology, Hungarian Academy of Sciences and Semmelweis University, Budapest, Hungary (L.S.E., P.V., L.H., A.B.); and Section on Molecular Signal Transduction, Program for Developmental Neuroscience, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland (T.B.)
| | - András D Tóth
- Department of Physiology, Semmelweis University, Faculty of Medicine, Budapest, Hungary (G.S., A.D.T., I.O., L.S.E., P.V., L.H., A.B.), Magyar Tudományos Akadémia-Semmelweis Egyetem Laboratory of Molecular Physiology, Hungarian Academy of Sciences and Semmelweis University, Budapest, Hungary (L.S.E., P.V., L.H., A.B.); and Section on Molecular Signal Transduction, Program for Developmental Neuroscience, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland (T.B.)
| | - Ilona Oláh
- Department of Physiology, Semmelweis University, Faculty of Medicine, Budapest, Hungary (G.S., A.D.T., I.O., L.S.E., P.V., L.H., A.B.), Magyar Tudományos Akadémia-Semmelweis Egyetem Laboratory of Molecular Physiology, Hungarian Academy of Sciences and Semmelweis University, Budapest, Hungary (L.S.E., P.V., L.H., A.B.); and Section on Molecular Signal Transduction, Program for Developmental Neuroscience, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland (T.B.)
| | - László Sándor Erdélyi
- Department of Physiology, Semmelweis University, Faculty of Medicine, Budapest, Hungary (G.S., A.D.T., I.O., L.S.E., P.V., L.H., A.B.), Magyar Tudományos Akadémia-Semmelweis Egyetem Laboratory of Molecular Physiology, Hungarian Academy of Sciences and Semmelweis University, Budapest, Hungary (L.S.E., P.V., L.H., A.B.); and Section on Molecular Signal Transduction, Program for Developmental Neuroscience, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland (T.B.)
| | - Tamas Balla
- Department of Physiology, Semmelweis University, Faculty of Medicine, Budapest, Hungary (G.S., A.D.T., I.O., L.S.E., P.V., L.H., A.B.), Magyar Tudományos Akadémia-Semmelweis Egyetem Laboratory of Molecular Physiology, Hungarian Academy of Sciences and Semmelweis University, Budapest, Hungary (L.S.E., P.V., L.H., A.B.); and Section on Molecular Signal Transduction, Program for Developmental Neuroscience, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland (T.B.)
| | - Péter Várnai
- Department of Physiology, Semmelweis University, Faculty of Medicine, Budapest, Hungary (G.S., A.D.T., I.O., L.S.E., P.V., L.H., A.B.), Magyar Tudományos Akadémia-Semmelweis Egyetem Laboratory of Molecular Physiology, Hungarian Academy of Sciences and Semmelweis University, Budapest, Hungary (L.S.E., P.V., L.H., A.B.); and Section on Molecular Signal Transduction, Program for Developmental Neuroscience, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland (T.B.)
| | - László Hunyady
- Department of Physiology, Semmelweis University, Faculty of Medicine, Budapest, Hungary (G.S., A.D.T., I.O., L.S.E., P.V., L.H., A.B.), Magyar Tudományos Akadémia-Semmelweis Egyetem Laboratory of Molecular Physiology, Hungarian Academy of Sciences and Semmelweis University, Budapest, Hungary (L.S.E., P.V., L.H., A.B.); and Section on Molecular Signal Transduction, Program for Developmental Neuroscience, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland (T.B.)
| | - András Balla
- Department of Physiology, Semmelweis University, Faculty of Medicine, Budapest, Hungary (G.S., A.D.T., I.O., L.S.E., P.V., L.H., A.B.), Magyar Tudományos Akadémia-Semmelweis Egyetem Laboratory of Molecular Physiology, Hungarian Academy of Sciences and Semmelweis University, Budapest, Hungary (L.S.E., P.V., L.H., A.B.); and Section on Molecular Signal Transduction, Program for Developmental Neuroscience, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland (T.B.)
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Szebényi K, Füredi A, Kolacsek O, Csohány R, Prókai Á, Kis-Petik K, Szabó A, Bősze Z, Bender B, Tóvári J, Enyedi Á, Orbán TI, Apáti Á, Sarkadi B. Visualization of Calcium Dynamics in Kidney Proximal Tubules. J Am Soc Nephrol 2015; 26:2731-40. [PMID: 25788535 DOI: 10.1681/asn.2014070705] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2014] [Accepted: 01/08/2015] [Indexed: 12/28/2022] Open
Abstract
Intrarenal changes in cytoplasmic calcium levels have a key role in determining pathologic and pharmacologic responses in major kidney diseases. However, cell-specific delivery of calcium-sensitive probes in vivo remains problematic. We generated a transgenic rat stably expressing the green fluorescent protein-calmodulin-based genetically encoded calcium indicator (GCaMP2) predominantly in the kidney proximal tubules. The transposon-based method used allowed the generation of homozygous transgenic rats containing one copy of the transgene per allele with a defined insertion pattern, without genetic or phenotypic alterations. We applied in vitro confocal and in vivo two-photon microscopy to examine basal calcium levels and ligand- and drug-induced alterations in these levels in proximal tubular epithelial cells. Notably, renal ischemia induced a transient increase in cellular calcium, and reperfusion resulted in a secondary calcium load, which was significantly decreased by systemic administration of specific blockers of the angiotensin receptor and the Na-Ca exchanger. The parallel examination of in vivo cellular calcium dynamics and renal circulation by fluorescent probes opens new possibilities for physiologic and pharmacologic investigations.
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Affiliation(s)
- Kornélia Szebényi
- Institute of Enzymology, Research Centre for Natural Sciences, Hungarian Academy of Sciences, Budapest, Hungary
| | - András Füredi
- Institute of Enzymology, Research Centre for Natural Sciences, Hungarian Academy of Sciences, Budapest, Hungary
| | - Orsolya Kolacsek
- Institute of Enzymology, Research Centre for Natural Sciences, Hungarian Academy of Sciences, Budapest, Hungary
| | | | | | - Katalin Kis-Petik
- Department of Biophysics and Radiation Biology, MTA-SE Molecular Biophysics Research Group, and
| | - Attila Szabó
- MTA-SE, Pediatrics and Nephrology Research Group, Budapest, Hungary
| | | | | | - József Tóvári
- Department of Experimental Pharmacology, National Institute of Oncology, Budapest, Hungary
| | - Ágnes Enyedi
- Second Department of Pathology, Semmelweis University, Budapest, Hungary
| | - Tamás I Orbán
- Institute of Enzymology, Research Centre for Natural Sciences, Hungarian Academy of Sciences, Budapest, Hungary
| | - Ágota Apáti
- Institute of Enzymology, Research Centre for Natural Sciences, Hungarian Academy of Sciences, Budapest, Hungary;
| | - Balázs Sarkadi
- Institute of Enzymology, Research Centre for Natural Sciences, Hungarian Academy of Sciences, Budapest, Hungary; Department of Biophysics and Radiation Biology, MTA-SE Molecular Biophysics Research Group, and
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Tóth DJ, Tóth JT, Gulyás G, Balla A, Balla T, Hunyady L, Várnai P. Acute depletion of plasma membrane phosphatidylinositol 4,5-bisphosphate impairs specific steps in endocytosis of the G-protein-coupled receptor. J Cell Sci 2012; 125:2185-97. [PMID: 22357943 DOI: 10.1242/jcs.097279] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Receptor endocytosis plays an important role in regulating the responsiveness of cells to specific ligands. Phosphatidylinositol 4,5-bisphosphate [PtdIns(4,5)P(2)] has been shown to be crucial for endocytosis of some cell surface receptors, such as EGF and transferrin receptors, but its role in G-protein-coupled receptor internalization has not been investigated. By using luciferase-labeled type 1 angiotensin II (AT1R), type 2C serotonin (5HT2CR) or β(2) adrenergic (β2AR) receptors and fluorescently tagged proteins (β-arrestin-2, plasma-membrane-targeted Venus, Rab5) we were able to follow the sequence of molecular interactions along the endocytic route of the receptors in HEK293 cells using the highly sensitive method of bioluminescence resonance energy transfer and confocal microscopy. To study the role of plasma membrane PtdIns(4,5)P(2) in receptor endocytosis, we used our previously developed rapamycin-inducible heterodimerization system, in which the recruitment of a 5-phosphatase domain to the plasma membrane degrades PtdIns(4,5)P(2). Here we show that ligand-induced interaction of AT1, 5HT2C and β(2)A receptors with β-arrestin-2 was unaffected by PtdIns(4,5)P(2) depletion. However, trafficking of the receptors to Rab5-positive early endosomes was completely abolished in the absence of PtdIns(4,5)P(2). Remarkably, removal of the receptors from the plasma membrane was reduced but not eliminated after PtdIns(4,5)P(2) depletion. Under these conditions, stimulated AT1 receptors clustered along the plasma membrane, but did not enter the cells. Our data suggest that in the absence of PtdIns(4,5)P(2), these receptors move into clathrin-coated membrane structures, but these are not cleaved efficiently and hence cannot reach the early endosomal compartment.
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Affiliation(s)
- Dániel J Tóth
- Department of Physiology, Semmelweis University, Faculty of Medicine, Budapest, Hungary
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Lyngsø C, Erikstrup N, Hansen JL. Functional interactions between 7TM receptors in the renin-angiotensin system--dimerization or crosstalk? Mol Cell Endocrinol 2009; 302:203-12. [PMID: 18930783 DOI: 10.1016/j.mce.2008.09.018] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/19/2008] [Revised: 09/09/2008] [Accepted: 09/10/2008] [Indexed: 12/15/2022]
Abstract
The Renin-Angiotensin System (RAS) is important for the regulation of cardiovascular physiology, where it controls blood pressure, and salt- and water homeostasis. Dysregulation of RAS can lead to severe diseases including hypertension, diabetic nephropathy, and cardiac arrhythmia, and -failure. The importance of the RAS is clearly emphasised by the widespread use of drugs targeting this system in clinical practice. These include, renin inhibitors, angiotensin II receptor type I blockers, and inhibitors of the angiotensin converting enzyme. Some of the important effectors within the system are 7 transmembrane (7TM) receptors (or G-protein-coupled receptors) such as the angiotensin II Receptors type I and II (AT1R and AT2R) and the MAS-oncogene receptor. Several findings indicate that the 7TM receptors can form both homo- and heterodimers, or higher orders of oligomers. Furthermore, dimerization may be important for receptor function, and in the development of cardiovascular diseases. This is very significant, since "dimers" may provide pharmacologists with novel targets for improved drug therapy. However, we know that 7TM receptors can mediate signals as monomeric units, and so far it has been very difficult to establish if our observations reflect actual well-defined dimerization or merely reflect close proximity between the receptors and/or various types of functional interaction. In this review, we will present and critically discuss the current data on 7TM receptor dimerization with a clear focus on the RAS, and delineate future challenges within the field.
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Affiliation(s)
- Christina Lyngsø
- Danish National Research Foundation Centre for Cardiac Arrhythmia, Department of Neuroscience and Pharmacology, University of Copenhagen, Copenhagen, Denmark
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Szekeres M, Turu G, Orient A, Szalai B, Süpeki K, Cserzo M, Várnai P, Hunyady L. Mechanisms of angiotensin II-mediated regulation of aldosterone synthase expression in H295R human adrenocortical and rat adrenal glomerulosa cells. Mol Cell Endocrinol 2009; 302:244-53. [PMID: 19418629 DOI: 10.1016/j.mce.2008.12.015] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
In adrenal zona glomerulosa cells angiotensin II (Ang II) is a key regulator of steroidogenesis. Our purpose was to compare the mechanisms of Ang II-induced changes in the expression level of early transcription factors NR4A1 (NGFIB) and NR4A2 (Nurr1) genes, and the CYP11B2 gene encoding aldosterone synthase in H295R human adrenocortical tumor cells and in primary rat adrenal glomerulosa cells. Real-time PCR studies have demonstrated that Ang II increased the expression levels of NR4A1 and NR4A2 in H295R cells within 1 h after stimulation, which persisted up to 6 h; whereas in rat adrenal glomerulosa cells the kinetics of the expression of these genes were more rapid and transient. Ang II also induced prolonged nuclear translocation of Nurr1 and NGFIB proteins in both cell types. Studies using MEK inhibitor (PD98059, 20 microM), protein kinase C inhibitor (BIM1, 3 microM) and calmodulin kinase (CAMK) inhibitor (KN93, 10 microM) revealed that in rat adrenal glomerulosa cells CAMK-mediated mechanisms play a predominant role in the regulation of CYP11B2. In accordance with earlier findings, in H295R cells MEK inhibition increased the expression of NR4A1, NR4A2 and CYP11B2 genes, however, it decreased the Ang II-induced gene expression levels, suggesting that ERK activation has a role in control of expression of these genes. No such mechanism was detected in rat glomerulosa cells. Sar1-Ile4-Ile8-AngII, which can cause G protein-independent ERK activation, also stimulated the expression of CYP11B2 in H295R cells. These data suggest that the previously reported CAMK-mediated stimulation of early transcription factors NGFIB and Nurr1 has a predominant role in Ang II-induced CYP11B2 activation in rat adrenal glomerulosa cells, whereas in H295R cells ERK activation and G protein-independent mechanisms also contribute to this process.
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Affiliation(s)
- Mária Szekeres
- Department of Physiology, Semmelweis University, Faculty of Medicine, Budapest, Hungary.
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