1
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TRPP2 ion channels: The roles in various subcellular locations. Biochimie 2022; 201:116-127. [PMID: 35760123 DOI: 10.1016/j.biochi.2022.06.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2021] [Revised: 06/14/2022] [Accepted: 06/22/2022] [Indexed: 11/21/2022]
Abstract
TRPP2 (PC2, PKD2 or Polycytin-2), encoded by PKD2 gene, belongs to the nonselective cation channel TRP family. Recently, the three-dimensional structure of TRPP2 was constructed. TRPP2 mainly functions in three subcellular compartments: endoplasmic reticulum, plasma membrane and primary cilia. TRPP2 can act as a calcium-activated intracellular calcium release channel on the endoplasmic reticulum. TRPP2 also interacts with other Ca2+ release channels to regulate calcium release, like IP3R and RyR2. TRPP2 acts as an ion channel regulated by epidermal growth factor through activation of downstream factors in the plasma membrane. TRPP2 binding to TRPC1 in the plasma membrane or endoplasmic reticulum is associated with mechanosensitivity. In cilium, TRPP2 was found to combine with PKD1 and TRPV4 to form a complex related to mechanosensitivity. Because TRPP2 is involved in regulating intracellular ion concentration, TRPP2 mutations often lead to autosomal dominant polycystic kidney disease, which may also be associated with cardiovascular disease. In this paper, we review the molecular structure of TRPP2, the subcellular localization of TRPP2, the related functions and mechanisms of TRPP2 at different sites, and the diseases related to TRPP2.
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2
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Cantero MDR, Cantiello HF. Polycystin-2 (TRPP2): Ion channel properties and regulation. Gene 2022; 827:146313. [PMID: 35314260 DOI: 10.1016/j.gene.2022.146313] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2021] [Revised: 01/19/2022] [Accepted: 02/08/2022] [Indexed: 12/01/2022]
Abstract
Polycystin-2 (TRPP2, PKD2, PC2) is the product of the PKD2 gene, whose mutations cause Autosomal Dominant Polycystic Kidney Disease (ADPKD). PC2 belongs to the superfamily of TRP (Transient Receptor Potential) proteins that generally function as Ca2+-permeable nonselective cation channels implicated in Ca2+ signaling. PC2 localizes to various cell domains with distinct functions that likely depend on interactions with specific channel partners. Functions include receptor-operated, nonselective cation channel activity in the plasma membrane, intracellular Ca2+ release channel activity in the endoplasmic reticulum (ER), and mechanosensitive channel activity in the primary cilium of renal epithelial cells. Here we summarize our current understanding of the properties of PC2 and how other transmembrane and cytosolic proteins modulate this activity, providing functional diversity and selective regulatory mechanisms to its role in the control of cellular Ca2+ homeostasis.
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Affiliation(s)
- María Del Rocío Cantero
- Laboratorio de Canales Iónicos, Instituto Multidisciplinario de Salud, Tecnología y Desarrollo (IMSaTeD, CONICET-UNSE), El Zanjón, Santiago del Estero 4206, Argentina.
| | - Horacio F Cantiello
- Laboratorio de Canales Iónicos, Instituto Multidisciplinario de Salud, Tecnología y Desarrollo (IMSaTeD, CONICET-UNSE), El Zanjón, Santiago del Estero 4206, Argentina
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3
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Priolo M, Mancini C, Pizzi S, Chiriatti L, Radio FC, Cordeddu V, Pintomalli L, Mammì C, Dallapiccola B, Tartaglia M. Complex Presentation of Hao-Fountain Syndrome Solved by Exome Sequencing Highlighting Co-Occurring Genomic Variants. Genes (Basel) 2022; 13:genes13050889. [PMID: 35627274 PMCID: PMC9141324 DOI: 10.3390/genes13050889] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2022] [Revised: 05/02/2022] [Accepted: 05/11/2022] [Indexed: 01/05/2023] Open
Abstract
Objective: The co-occurrence of pathogenic variants has emerged as a relatively common finding underlying complex phenotypes. Here, we used whole-exome sequencing (WES) to solve an unclassified multisystem clinical presentation. Patients and Methods: A 20-year-old woman affected by moderate intellectual disability (ID), dysmorphic features, hypertrichosis, scoliosis, recurrent bronchitis, and pneumonia with bronchiectasis, colelithiasis, chronic severe constipation, and a family history suggestive of autosomal dominant recurrence of polycystic kidney disease was analyzed by WES to identify the genomic events underlying the condition. Results: Four co-occurring genomic events fully explaining the proband’s clinical features were identified. A de novo truncating USP7 variant was disclosed as the cause of Hao–Fountain syndrome, a disorder characterized by syndromic ID and distinctive behavior. Compound heterozygosity for a major cystic fibrosis-causing variant and the modulator allele, IVS8-5T, in CFTR explained the recurrent upper and lower respiratory way infections, bronchiectasis, cholelithiasis, and chronic constipation. Finally, a truncating PKD2 variant co-segregating with polycystic kidney disease in the family allowed presymptomatic disease diagnosis. Conclusions: The co-occurring variants in USP7 and CFTR variants explained the multisystem disorder of the patient. The comprehensive dissection of the phenotype and early diagnosis of autosomal dominant polycystic kidney disease allowed us to manage the CFTR-related disorder symptoms and monitor renal function and other complications associated with PKD2 haploinsufficiency, addressing proper care and surveillance.
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Affiliation(s)
- Manuela Priolo
- Unità di Genetica Medica, Grande Ospedale Metropolitano “Bianchi-Melacrino-Morelli”, 89124 Reggio Calabria, Italy; (L.C.); (L.P.); (C.M.)
- Correspondence: ; Tel.: +39-09-6539-7319
| | - Cecilia Mancini
- Area di Ricerca Genetica e Malattie Rare, Ospedale Pediatrico Bambino Gesù, IRCCS, 00146 Rome, Italy; (C.M.); (S.P.); (F.C.R.); (B.D.); (M.T.)
| | - Simone Pizzi
- Area di Ricerca Genetica e Malattie Rare, Ospedale Pediatrico Bambino Gesù, IRCCS, 00146 Rome, Italy; (C.M.); (S.P.); (F.C.R.); (B.D.); (M.T.)
| | - Luigi Chiriatti
- Unità di Genetica Medica, Grande Ospedale Metropolitano “Bianchi-Melacrino-Morelli”, 89124 Reggio Calabria, Italy; (L.C.); (L.P.); (C.M.)
| | - Francesca Clementina Radio
- Area di Ricerca Genetica e Malattie Rare, Ospedale Pediatrico Bambino Gesù, IRCCS, 00146 Rome, Italy; (C.M.); (S.P.); (F.C.R.); (B.D.); (M.T.)
| | - Viviana Cordeddu
- Dipartimento di Oncologia e Medicina Molecolare, Istituto Superiore di Sanità, 00161 Rome, Italy;
| | - Letizia Pintomalli
- Unità di Genetica Medica, Grande Ospedale Metropolitano “Bianchi-Melacrino-Morelli”, 89124 Reggio Calabria, Italy; (L.C.); (L.P.); (C.M.)
| | - Corrado Mammì
- Unità di Genetica Medica, Grande Ospedale Metropolitano “Bianchi-Melacrino-Morelli”, 89124 Reggio Calabria, Italy; (L.C.); (L.P.); (C.M.)
| | - Bruno Dallapiccola
- Area di Ricerca Genetica e Malattie Rare, Ospedale Pediatrico Bambino Gesù, IRCCS, 00146 Rome, Italy; (C.M.); (S.P.); (F.C.R.); (B.D.); (M.T.)
| | - Marco Tartaglia
- Area di Ricerca Genetica e Malattie Rare, Ospedale Pediatrico Bambino Gesù, IRCCS, 00146 Rome, Italy; (C.M.); (S.P.); (F.C.R.); (B.D.); (M.T.)
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4
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Cytopenia in autosomal dominant polycystic kidney disease (ADPKD): merely an association or a disease-related feature with prognostic implications? Pediatr Nephrol 2021; 36:3505-3514. [PMID: 33502599 DOI: 10.1007/s00467-021-04937-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/26/2020] [Revised: 12/03/2020] [Accepted: 01/08/2021] [Indexed: 10/22/2022]
Abstract
Autosomal dominant polycystic kidney disease (ADPKD) is associated with distinct cytopenias in observational studies; the most consistent and strongest association is seen with alternations in the lymphocytic lineages. Although the underlying mechanism of these associations is unclear, it has been hypothesized to be secondary to sequestration of white blood cells in cystic organs, or related to the uremic environment in chronic kidney disease (CKD). However, since mutations in PKD1 or -2 affect several immunomodulating pathways, cytopenia may well be an unrecognized extrarenal manifestation of ADPKD. Furthermore, many important questions on the clinical implications of this finding and the effect on the disease course in these patients are unanswered. In this review article, we provide an overview of the current evidence on cytopenia in ADPKD and explore the underlying mechanisms of this association and its potential prognostic implications. Based on the current literature, we hypothesize that polycystin deficiency can disturb immune cell homeostasis and that cytopenia is thus an intrinsic feature of ADPKD, related to genetic factors. Taken together, these findings warrant further investigation to establish the exact etiology and role of cytopenia in patients with ADPKD.
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5
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The cellular pathways and potential therapeutics of Polycystic Kidney Disease. Biochem Soc Trans 2021; 49:1171-1188. [PMID: 34156429 DOI: 10.1042/bst20200757] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2021] [Revised: 05/28/2021] [Accepted: 06/03/2021] [Indexed: 02/07/2023]
Abstract
Polycystic Kidney Disease (PKD) refers to a group of disorders, driven by the formation of cysts in renal tubular cells and is currently one of the leading causes of end-stage renal disease. The range of symptoms observed in PKD is due to mutations in cilia-localising genes, resulting in changes in cellular signalling. As such, compounds that are currently in preclinical and clinical trials target some of these signalling pathways that are dysregulated in PKD. In this review, we highlight these pathways including cAMP, EGF and AMPK signalling and drugs that target them and may show promise in lessening the disease burden of PKD patients. At present, tolvaptan is the only approved therapy for ADPKD, however, it carries several adverse side effects whilst comparatively, no pharmacological drug is approved for ARPKD treatment. Aside from this, drugs that have been the subject of multiple clinical trials such as metformin, which targets AMPK signalling and somatostatins, which target cAMP signalling have shown great promise in reducing cyst formation and cellular proliferation. This review also discusses other potential and novel targets that can be used for future interventions, such as β-catenin and TAZ, where research has shown that a reduction in the overexpression of these signalling components results in amelioration of disease phenotype. Thus, it becomes apparent that well-designed preclinical investigations and future clinical trials into these pathways and other potential signalling targets are crucial in bettering disease prognosis for PKD patients and could lead to personalised therapy approaches.
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6
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Brücker L, Kretschmer V, May-Simera HL. The entangled relationship between cilia and actin. Int J Biochem Cell Biol 2020; 129:105877. [PMID: 33166678 DOI: 10.1016/j.biocel.2020.105877] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2020] [Revised: 10/23/2020] [Accepted: 10/26/2020] [Indexed: 12/14/2022]
Abstract
Primary cilia are microtubule-based sensory cell organelles that are vital for tissue and organ development. They act as an antenna, receiving and transducing signals, enabling communication between cells. Defects in ciliogenesis result in severe genetic disorders collectively termed ciliopathies. In recent years, the importance of the direct and indirect involvement of actin regulators in ciliogenesis came into focus as it was shown that F-actin polymerisation impacts ciliation. The ciliary basal body was further identified as both a microtubule and actin organising centre. In the current review, we summarize recent studies on F-actin in and around primary cilia, focusing on different actin regulators and their effect on ciliogenesis, from the initial steps of basal body positioning and regulation of ciliary assembly and disassembly. Since primary cilia are also involved in several intracellular signalling pathways such as planar cell polarity (PCP), subsequently affecting actin rearrangements, the multiple effectors of this pathway are highlighted in more detail with a focus on the feedback loops connecting actin networks and cilia proteins. Finally, we elucidate the role of actin regulators in the development of ciliopathy symptoms and cancer.
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Affiliation(s)
- Lena Brücker
- Cilia Cell Biology, Institute of Molecular Physiology, Johannes-Gutenberg University, Mainz, Germany
| | - Viola Kretschmer
- Cilia Cell Biology, Institute of Molecular Physiology, Johannes-Gutenberg University, Mainz, Germany
| | - Helen Louise May-Simera
- Cilia Cell Biology, Institute of Molecular Physiology, Johannes-Gutenberg University, Mainz, Germany.
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7
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Palander O, Trimble WS. DIAPH1 regulates ciliogenesis and trafficking in primary cilia. FASEB J 2020; 34:16516-16535. [PMID: 33124112 DOI: 10.1096/fj.202001178r] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2020] [Revised: 09/08/2020] [Accepted: 10/12/2020] [Indexed: 01/29/2023]
Abstract
Primary cilia are critical hubs for several signaling pathways, and defects in ciliogenesis or cilia maintenance produce a range of diseases collectively known as ciliopathies. Ciliogenesis requires vesicle trafficking along a network of microtubules and actin filaments to the basal body. The DIAPH1 (Diaphanous-related formin) family of formins promotes both actin polymerization and EB1-dependent microtubule (MT) stability. EB1 and EB3 have previously been implicated in cilia biogenesis to carry out centrosome-related functions. However, the role of DIAPH1 proteins had not been examined. Here we show that the depletion of DIAPH1 decreased ciliogenesis, cilia length, and reduced trafficking within cilia. Additionally, both actin nucleating and microtubule-stabilizing properties of DIAPH1 are important for their cilia functions. To assess their roles in ciliogenesis in isolation, we targeted DIAPH1 specifically to the basal body, which caused an increase in cilia length and increased trafficking within cilia. Intriguingly, expression of DIAPH1 mutants associated with human deafness and microcephaly impaired ciliation and caused cilia elongation and bulb formation. These results suggest that the actin and microtubule functions of DIAPH1 proteins regulate cilia maintenance in part by regulating vesicular trafficking to the base of the primary cilia.
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Affiliation(s)
- Oliva Palander
- Cell Biology Program, Hospital for Sick Children, Toronto, ON, Canada.,Department of Biochemistry, University of Toronto, Toronto, ON, Canada
| | - William S Trimble
- Cell Biology Program, Hospital for Sick Children, Toronto, ON, Canada.,Department of Biochemistry, University of Toronto, Toronto, ON, Canada
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8
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Streets A, Ong A. Post-translational modifications of the polycystin proteins. Cell Signal 2020; 72:109644. [PMID: 32320857 DOI: 10.1016/j.cellsig.2020.109644] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2020] [Revised: 04/15/2020] [Accepted: 04/15/2020] [Indexed: 12/12/2022]
Abstract
Autosomal dominant polycystic kidney disease (ADPKD) is the most common inherited cause of kidney failure and affects up to 12 million people worldwide. Germline mutations in two genes, PKD1 or PKD2, account for almost all patients with ADPKD. The ADPKD proteins, polycystin-1 (PC1) and polycystin-2 (PC2), are regulated by post-translational modifications (PTM), with phosphorylation, glycosylation and proteolytic cleavage being the best described changes. A few PTMs have been shown to regulate polycystin trafficking, signalling, localisation or stability and thus their physiological function. A key challenge for the future will be to elucidate the functional significance of all the individual PTMs reported to date. Finally, it is possible that site-specific mutations that disrupt PTM could contribute to cystogenesis although in the majority of cases, confirmatory evidence is awaited.
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Affiliation(s)
- Andrew Streets
- Kidney Genetics Group, Academic Nephrology Unit, University of Sheffield Medical School, Sheffield, UK.
| | - Albert Ong
- Kidney Genetics Group, Academic Nephrology Unit, University of Sheffield Medical School, Sheffield, UK
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9
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Polycystins as components of large multiprotein complexes of polycystin interactors. Cell Signal 2020; 72:109640. [PMID: 32305669 DOI: 10.1016/j.cellsig.2020.109640] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2020] [Revised: 04/14/2020] [Accepted: 04/14/2020] [Indexed: 12/27/2022]
Abstract
Naturally occurring mutations in two separate genes, PKD1 and PKD2, are responsible for the vast majority of all cases of autosomal dominant polycystic kidney disease (ADPKD), one of the most common genetic diseases affecting 1 in 1000 Americans. The hallmark of ADPKD is the development of epithelial cysts in the kidney, liver, and pancreas. PKD1 encodes a large plasma membrane protein (PKD1, PC1, or Polycystin-1) with a long extracellular domain and has been speculated to function as an atypical G protein coupled receptor. PKD2 encodes an ion channel of the Transient Receptor Potential superfamily (TRPP2, PKD2, PC2, or Polycystin-2). Despite the identification of these genes more than 20 years ago, the molecular function of their encoded proteins and the mechanism(s) by which mutations in PKD1 and PKD2 cause ADPKD remain elusive. Genetic, biochemical, and functional evidence suggests they form a multiprotein complex present in multiple locations in the cell, including the plasma membrane, endoplasmic reticulum, and the primary cilium. Over the years, numerous interacting proteins have been identified using directed and unbiased approaches, and shown to modulate function, cellular localization, and protein stability and turnover of Polycystins. Delineation of the molecular composition of the Polycystin complex can have a significant impact on understanding their cellular function in health and disease states and on the identification of more specific and effective therapeutic targets.
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10
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Morris Z, Sinha D, Poddar A, Morris B, Chen Q. Fission yeast TRP channel Pkd2p localizes to the cleavage furrow and regulates cell separation during cytokinesis. Mol Biol Cell 2019; 30:1791-1804. [PMID: 31116668 PMCID: PMC6727746 DOI: 10.1091/mbc.e18-04-0270] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Force plays a central role in separating daughter cells during cytokinesis, the last stage of cell division. However, the mechanism of force sensing during cytokinesis remains unknown. Here we discovered that Pkd2p, a putative force-sensing transient receptor potential channel, localizes to the cleavage furrow during cytokinesis of the fission yeast, Schizosaccharomyces pombe. Pkd2p, whose human homologues are associated with autosomal polycystic kidney disease, is an essential protein whose localization depends on the contractile ring and the secretory pathway. We identified and characterized a novel pkd2 mutant pkd2-81KD. The pkd2 mutant cells show signs of osmotic stress, including temporary shrinking, paused turnover of the cytoskeletal structures, and hyperactivated mitogen-activated protein kinase signaling. During cytokinesis, although the contractile ring constricts more rapidly in the pkd2 mutant than the wild-type cells (50% higher), the cell separation in the mutant is slower and often incomplete. These cytokinesis defects are also consistent with misregulated turgor pressure. Finally, the pkd2 mutant exhibits strong genetic interactions with two mutants of the septation initiation network pathway, a signaling cascade essential for cytokinesis. We propose that Pkd2p modulates osmotic homeostasis and is potentially a novel regulator of cytokinesis.
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Affiliation(s)
- Zachary Morris
- Department of Biological Sciences, University of Toledo, Toledo, OH 43606
| | - Debatrayee Sinha
- Department of Biological Sciences, University of Toledo, Toledo, OH 43606
| | - Abhishek Poddar
- Department of Biological Sciences, University of Toledo, Toledo, OH 43606
| | - Brittni Morris
- Department of Biological Sciences, University of Toledo, Toledo, OH 43606
| | - Qian Chen
- Department of Biological Sciences, University of Toledo, Toledo, OH 43606
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11
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Moisan S, Levon S, Cornec-Le Gall E, Le Meur Y, Audrézet MP, Dostie J, Férec C. Novel long-range regulatory mechanisms controlling PKD2 gene expression. BMC Genomics 2018; 19:515. [PMID: 29986647 PMCID: PMC6038307 DOI: 10.1186/s12864-018-4892-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2017] [Accepted: 06/20/2018] [Indexed: 02/01/2023] Open
Abstract
Background Cis-regulatory elements control gene expression over large distances through the formation of chromatin loops, which allow contact between enhancers and gene promoters. Alterations in cis-acting regulatory systems could be linked to human genetic diseases. Here, we analyse the spatial organization of a large region spanning the polycystic kidney disease 2 (PKD2) gene, one of the genes responsible of autosomal dominant polycystic kidney disease (ADPKD). Results By using chromosome conformation capture carbon copy (5C) technology in primary human renal cyst epithelial cells, we identify novel contacts of the PKD2 promoter with chromatin regions, which display characteristics of regulatory elements. In parallel, by using functional analysis with a reporter assay, we demonstrate that three DNAse I hypersensitive sites regions are involved in the regulation of PKD2 gene expression. Conclusions Finally, through alignment of CCCTC-binding factor (CTCF) sites, we suggest that these novel enhancer elements are brought to the PKD2 promoter by chromatin looping via the recruitment of CTCF. Electronic supplementary material The online version of this article (10.1186/s12864-018-4892-6) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Stéphanie Moisan
- Institut National de la Santé et de la Recherche Médicale (INSERM), U1078, Brest, Bretagne, France. .,Faculté de Médecine et des Sciences de la Santé, Université de Bretagne Occidentale (UBO), Brest, Bretagne, France. .,Laboratoire de Génétique Moléculaire et d'Histocompatibilité, Centre Hospitalier Régional Universitaire (CHRU), Hôpital Morvan, Brest, Bretagne, France.
| | - Stéphanie Levon
- Institut National de la Santé et de la Recherche Médicale (INSERM), U1078, Brest, Bretagne, France.,Faculté de Médecine et des Sciences de la Santé, Université de Bretagne Occidentale (UBO), Brest, Bretagne, France
| | - Emilie Cornec-Le Gall
- Institut National de la Santé et de la Recherche Médicale (INSERM), U1078, Brest, Bretagne, France.,Laboratoire de Génétique Moléculaire et d'Histocompatibilité, Centre Hospitalier Régional Universitaire (CHRU), Hôpital Morvan, Brest, Bretagne, France
| | - Yannick Le Meur
- Service de néphrologie, Centre Hospitalier Régional Universitaire (CHRU), Brest, Bretagne, France
| | - Marie-Pierre Audrézet
- Institut National de la Santé et de la Recherche Médicale (INSERM), U1078, Brest, Bretagne, France.,Laboratoire de Génétique Moléculaire et d'Histocompatibilité, Centre Hospitalier Régional Universitaire (CHRU), Hôpital Morvan, Brest, Bretagne, France
| | - Josée Dostie
- Department of Biochemistry and Goodman Cancer Research Center, McGill University, Montréal, Québec, Canada
| | - Claude Férec
- Institut National de la Santé et de la Recherche Médicale (INSERM), U1078, Brest, Bretagne, France. .,Faculté de Médecine et des Sciences de la Santé, Université de Bretagne Occidentale (UBO), Brest, Bretagne, France. .,Laboratoire de Génétique Moléculaire et d'Histocompatibilité, Centre Hospitalier Régional Universitaire (CHRU), Hôpital Morvan, Brest, Bretagne, France. .,Etablissement Français du sang (EFS), Brest, Bretagne, France.
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12
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Hua K, Ferland RJ. Primary cilia proteins: ciliary and extraciliary sites and functions. Cell Mol Life Sci 2018; 75:1521-1540. [PMID: 29305615 PMCID: PMC5899021 DOI: 10.1007/s00018-017-2740-5] [Citation(s) in RCA: 50] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2017] [Revised: 12/21/2017] [Accepted: 12/27/2017] [Indexed: 02/07/2023]
Abstract
Primary cilia are immotile organelles known for their roles in development and cell signaling. Defects in primary cilia result in a range of disorders named ciliopathies. Because this organelle can be found singularly on almost all cell types, its importance extends to most organ systems. As such, elucidating the importance of the primary cilium has attracted researchers from all biological disciplines. As the primary cilia field expands, caution is warranted in attributing biological defects solely to the function of this organelle, since many of these "ciliary" proteins are found at other sites in cells and likely have non-ciliary functions. Indeed, many, if not all, cilia proteins have locations and functions outside the primary cilium. Extraciliary functions are known to include cell cycle regulation, cytoskeletal regulation, and trafficking. Cilia proteins have been observed in the nucleus, at the Golgi apparatus, and even in immune synapses of T cells (interestingly, a non-ciliated cell). Given the abundance of extraciliary sites and functions, it can be difficult to definitively attribute an observed phenotype solely to defective cilia rather than to some defective extraciliary function or a combination of both. Thus, extraciliary sites and functions of cilia proteins need to be considered, as well as experimentally determined. Through such consideration, we will understand the true role of the primary cilium in disease as compared to other cellular processes' influences in mediating disease (or through a combination of both). Here, we review a compilation of known extraciliary sites and functions of "cilia" proteins as a means to demonstrate the potential non-ciliary roles for these proteins.
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Affiliation(s)
- Kiet Hua
- Department of Neuroscience and Experimental Therapeutics, Albany Medical College, 47 New Scotland Avenue, MC-136, Albany, NY, 12208, USA.
| | - Russell J Ferland
- Department of Neuroscience and Experimental Therapeutics, Albany Medical College, 47 New Scotland Avenue, MC-136, Albany, NY, 12208, USA.
- Department of Neurology, Albany Medical College, Albany, NY, 12208, USA.
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13
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14
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Lemos FO, Ehrlich BE. Polycystin and calcium signaling in cell death and survival. Cell Calcium 2017; 69:37-45. [PMID: 28601384 DOI: 10.1016/j.ceca.2017.05.011] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2017] [Revised: 05/18/2017] [Accepted: 05/19/2017] [Indexed: 12/19/2022]
Abstract
Mutations in polycystin-1 (PC1) and polycystin-2 (PC2) result in a commonly occurring genetic disorder, called Autosomal Dominant Polycystic Kidney Disease (ADPKD), that is characterized by the formation and development of kidney cysts. Epithelial cells with loss-of-function of PC1 or PC2 show higher rates of proliferation and apoptosis and reduced autophagy. PC1 is a large multifunctional transmembrane protein that serves as a sensor that is usually found in complex with PC2, a calcium (Ca2+)-permeable cation channel. In addition to decreased Ca2+ signaling, several other cell fate-related pathways are de-regulated in ADPKD, including cAMP, MAPK, Wnt, JAK-STAT, Hippo, Src, and mTOR. In this review we discuss how polycystins regulate cell death and survival, highlighting the complexity of molecular cascades that are involved in ADPKD.
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Affiliation(s)
- Fernanda O Lemos
- Department of Pharmacology, Yale University, 333 Cedar St, New Haven, CT, 06520, USA
| | - Barbara E Ehrlich
- Department of Pharmacology, Yale University, 333 Cedar St, New Haven, CT, 06520, USA; Department of Cellular and Molecular Physiology, Yale University, 333 Cedar St, New Haven, CT, 06520, USA.
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15
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Polycystins and intercellular mechanotransduction: A precise dosage of polycystin 2 is necessary for alpha-actinin reinforcement of junctions upon mechanical stimulation. Exp Cell Res 2016; 348:23-35. [PMID: 27575580 DOI: 10.1016/j.yexcr.2016.08.021] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2016] [Revised: 08/06/2016] [Accepted: 08/25/2016] [Indexed: 12/19/2022]
Abstract
Polycystins 1 and 2, which are mutated in Autosomal Polycystic Kidney Disease, are involved in mechanotransduction through various mechanisms. In renal cells, polycystins not only have an important mechanotransductive role in primary cilia but are also present in intercellular contacts but their role there remains unclear. Here, we address the hypothesis that polycystins are involved in mechanotransduction via intercellular junctions, which would be expected to have consequences on tissue organization. We focused on the role of polycystin 2, which could be involved in mechanical organization at junctions either by its channel activity or by the direct recruitment of cytoskeleton components such as the F-actin cross-linker α-actinin. After mechanical stimulation of intercellular junctions in MDCK renal epithelial cells, α-actinin is rapidly recruited but this is inhibited upon overexpression of PC2 or the D509V mutant that lacks channel activity, and is also decreased upon PC2 silencing. This suggests that a precise dosage of PC2 is necessary for an adequate mechanosensitive α-actinin recruitment at junctions. At the multicellular level, a change in PC2 expression was associated with changes in velocity in confluent epithelia and during wound healing together with a loss of orientation. This study suggests that the mechanosensitive regulation of cytoskeleton by polycystins in intercellular contacts may be important in the context of ADPKD.
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16
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Zheng W, Shen F, Hu R, Roy B, Yang J, Wang Q, Zhang F, King JC, Sergi C, Liu SM, Cordat E, Tang J, Cao Y, Ali D, Chen XZ. Far Upstream Element-Binding Protein 1 Binds the 3' Untranslated Region of PKD2 and Suppresses Its Translation. J Am Soc Nephrol 2016; 27:2645-57. [PMID: 26839368 DOI: 10.1681/asn.2015070836] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2015] [Accepted: 11/24/2015] [Indexed: 01/02/2023] Open
Abstract
Autosomal dominant polycystic kidney disease pathogenesis can be recapitulated in animal models by gene mutations in or dosage alterations of polycystic kidney disease 1 (PKD1) or PKD2, demonstrating that too much and too little PKD1/PKD2 are both pathogenic. Gene dosage manipulation has become an appealing approach by which to compensate for loss or gain of gene function, but the mechanisms controlling PKD2 expression remain incompletely characterized. In this study, using cultured mammalian cells and dual-luciferase assays, we found that the 3' untranslated region (3'UTR) of PKD2 mRNA inhibits luciferase protein expression. We then identified nucleotides 691-1044, which we called 3FI, as the 3'UTR fragment necessary for repressing the expression of luciferase or PKD2 in this system. Using a pull-down assay and mass spectrometry we identified far upstream element-binding protein 1 (FUBP1) as a 3FI-binding protein. In vitro overexpression of FUBP1 inhibited the expression of PKD2 protein but not mRNA. In embryonic zebrafish, FUBP1 knockdown (KD) by morpholino injection increased PKD2 expression and alleviated fish tail curling caused by morpholino-mediated KD of PKD2. Conversely, FUBP1 overexpression by mRNA injection significantly increased pronephric cyst occurrence and tail curling in zebrafish embryos. Furthermore, FUBP1 binds directly to eukaryotic translation initiation factor 4E-binding protein 1, indicating a link to the translation initiation complex. These results show that FUBP1 binds 3FI in the PKD2 3'UTR to inhibit PKD2 translation, regulating zebrafish disease phenotypes associated with PKD2 KD.
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Affiliation(s)
- Wang Zheng
- Membrane Protein Disease and Cancer Research Centre, Provincial Innovation Center, Hubei University of Technology, Wuhan, China; Membrane Protein Disease Research Group, Department of Physiology
| | - Fan Shen
- Membrane Protein Disease Research Group, Department of Physiology, Medical Research Center, Zhongnan Hospital, Wuhan University, Wuhan, China; and
| | - Ruikun Hu
- School of Life Sciences and Technology, Tongji University, Shanghai, China
| | | | - JungWoo Yang
- Membrane Protein Disease Research Group, Department of Physiology
| | - Qian Wang
- Membrane Protein Disease Research Group, Department of Physiology
| | - Fan Zhang
- School of Life Sciences and Technology, Tongji University, Shanghai, China
| | - Jennifer C King
- Membrane Protein Disease Research Group, Department of Physiology
| | - Consolato Sergi
- Department of Laboratory Medicine and Pathology, University of Alberta, Edmonton, Alberta, Canada
| | - Song-Mei Liu
- Medical Research Center, Zhongnan Hospital, Wuhan University, Wuhan, China; and
| | | | - Jingfeng Tang
- Membrane Protein Disease and Cancer Research Centre, Provincial Innovation Center, Hubei University of Technology, Wuhan, China
| | - Ying Cao
- School of Life Sciences and Technology, Tongji University, Shanghai, China
| | | | - Xing-Zhen Chen
- Membrane Protein Disease and Cancer Research Centre, Provincial Innovation Center, Hubei University of Technology, Wuhan, China; Membrane Protein Disease Research Group, Department of Physiology,
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17
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The functions of TRPP2 in the vascular system. Acta Pharmacol Sin 2016; 37:13-8. [PMID: 26725733 DOI: 10.1038/aps.2015.126] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2015] [Accepted: 11/02/2015] [Indexed: 12/19/2022] Open
Abstract
TRPP2 (polycystin-2, PC2 or PKD2), encoded by the PKD2 gene, is a non-selective cation channel with a large single channel conductance and high Ca(2+) permeability. In cell membrane, TRPP2, along with polycystin-1, TRPV4 and TRPC1, functions as a mechanotransduction channel. In the endoplasmic reticulum, TRPP2 modulates intracellular Ca(2+) release associated with IP3 receptors and the ryanodine receptors. Noteworthily, TRPP2 is widely expressed in vascular endothelial and smooth muscle cells of all major vascular beds, and contributes to the regulation of vessel function. The mutation of the PKD2 gene is a major cause of autosomal dominant polycystic kidney disease (ADPKD), which is not only a common genetic disease of the kidney but also a systemic disorder associated with abnormalities in the vasculature; cardiovascular complications are the leading cause of mortality and morbidity in ADPKD patients. This review provides an overview of the current knowledge regarding the TRPP2 protein and its possible role in cardiovascular function and related diseases.
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18
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Vertii A, Bright A, Delaval B, Hehnly H, Doxsey S. New frontiers: discovering cilia-independent functions of cilia proteins. EMBO Rep 2015; 16:1275-87. [PMID: 26358956 DOI: 10.15252/embr.201540632] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2015] [Accepted: 08/17/2015] [Indexed: 12/11/2022] Open
Abstract
In most vertebrates, mitotic spindles and primary cilia arise from a common origin, the centrosome. In non-cycling cells, the centrosome is the template for primary cilia assembly and, thus, is crucial for their associated sensory and signaling functions. During mitosis, the duplicated centrosomes mature into spindle poles, which orchestrate mitotic spindle assembly, chromosome segregation, and orientation of the cell division axis. Intriguingly, both cilia and spindle poles are centrosome-based, functionally distinct structures that require the action of microtubule-mediated, motor-driven transport for their assembly. Cilia proteins have been found at non-cilia sites, where they have distinct functions, illustrating a diverse and growing list of cellular processes and structures that utilize cilia proteins for crucial functions. In this review, we discuss cilia-independent functions of cilia proteins and re-evaluate their potential contributions to "cilia" disorders.
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Affiliation(s)
- Anastassiia Vertii
- Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, MA, USA
| | - Alison Bright
- Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, MA, USA
| | | | - Heidi Hehnly
- Department of Cell and Developmental Biology, SUNY Upstate Medical University, Syracuse, NY, USA
| | - Stephen Doxsey
- Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, MA, USA
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19
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Wang Q, Zheng W, Wang Z, Yang J, Hussein S, Tang J, Chen XZ. Filamin-a increases the stability and plasma membrane expression of polycystin-2. PLoS One 2015; 10:e0123018. [PMID: 25861040 PMCID: PMC4393133 DOI: 10.1371/journal.pone.0123018] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2014] [Accepted: 02/26/2015] [Indexed: 12/13/2022] Open
Abstract
Polycystin-2 (PC2), encoded by the PKD2 gene, is mutated in ~15% of autosomal dominant polycystic kidney disease. Filamins are actin-binding proteins implicated in scaffolding and membrane stabilization. Here we studied the effects of filamin on PC2 stability using filamin-deficient human melanoma M2, filamin-A (FLNA)-replete A7, HEK293 and IMCD cells together with FLNA siRNA/shRNA knockdown (KD). We found that the presence of FLNA is associated with higher total and plasma membrane PC2 protein expression. Western blotting analysis in combination with FLNA KD showed that FLNA in A7 cells represses PC2 degradation, prolonging the half-life from 2.3 to 4.4 hours. By co-immunoprecipitation and Far Western blotting we found that the FLNA C-terminus (FLNAC) reduces the FLNA-PC2 binding and PC2 expression, presumably through competing with FLNA for binding PC2. We further found that FLNA mediates PC2 binding with actin through forming complex PC2-FLNA-actin. FLNAC acted as a blocking peptide and disrupted the link of PC2 with actin through disrupting the PC2-FLNA-actin complex. Finally, we demonstrated that the physical interaction of PC2-FLNA is Ca-dependent. Taken together, our current study indicates that FLNA anchors PC2 to the actin cytoskeleton through complex PC2-FLNA-actin to reduce degradation and increase stability, and possibly regulate PC2 function in a Ca-dependent manner.
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Affiliation(s)
- Qian Wang
- Membrane Protein Disease Research Group, Department of Physiology, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Alberta, Canada
| | - Wang Zheng
- Membrane Protein Disease Research Group, Department of Physiology, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Alberta, Canada
| | - Zuocheng Wang
- Membrane Protein Disease Research Group, Department of Physiology, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Alberta, Canada
| | - JungWoo Yang
- Membrane Protein Disease Research Group, Department of Physiology, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Alberta, Canada
| | - Shaimaa Hussein
- Membrane Protein Disease Research Group, Department of Physiology, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Alberta, Canada
| | - Jingfeng Tang
- Membrane Protein Disease Research Group, Department of Physiology, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Alberta, Canada
- Membrane Protein Disease and Cancer Research Center, Hubei University of Technology, Wuhan, China
- * E-mail: (XZC); (JFT)
| | - Xing-Zhen Chen
- Membrane Protein Disease Research Group, Department of Physiology, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Alberta, Canada
- Membrane Protein Disease and Cancer Research Center, Hubei University of Technology, Wuhan, China
- * E-mail: (XZC); (JFT)
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20
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Yue Z, Xie J, Yu AS, Stock J, Du J, Yue L. Role of TRP channels in the cardiovascular system. Am J Physiol Heart Circ Physiol 2015; 308:H157-82. [PMID: 25416190 PMCID: PMC4312948 DOI: 10.1152/ajpheart.00457.2014] [Citation(s) in RCA: 126] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/30/2014] [Accepted: 11/14/2014] [Indexed: 12/12/2022]
Abstract
The transient receptor potential (TRP) superfamily consists of a large number of nonselective cation channels with variable degree of Ca(2+)-permeability. The 28 mammalian TRP channel proteins can be grouped into six subfamilies: canonical, vanilloid, melastatin, ankyrin, polycystic, and mucolipin TRPs. The majority of these TRP channels are expressed in different cell types including both excitable and nonexcitable cells of the cardiovascular system. Unlike voltage-gated ion channels, TRP channels do not have a typical voltage sensor, but instead can sense a variety of other stimuli including pressure, shear stress, mechanical stretch, oxidative stress, lipid environment alterations, hypertrophic signals, and inflammation products. By integrating multiple stimuli and transducing their activity to downstream cellular signal pathways via Ca(2+) entry and/or membrane depolarization, TRP channels play an essential role in regulating fundamental cell functions such as contraction, relaxation, proliferation, differentiation, and cell death. With the use of targeted deletion and transgenic mouse models, recent studies have revealed that TRP channels are involved in numerous cellular functions and play an important role in the pathophysiology of many diseases in the cardiovascular system. Moreover, several TRP channels are involved in inherited diseases of the cardiovascular system. This review presents an overview of current knowledge concerning the physiological functions of TRP channels in the cardiovascular system and their contributions to cardiovascular diseases. Ultimately, TRP channels may become potential therapeutic targets for cardiovascular diseases.
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Affiliation(s)
- Zhichao Yue
- Calhoun Cardiology Center, Department of Cell Biology, University of Connecticut Health Center, Farmington, Connecticut
| | - Jia Xie
- Calhoun Cardiology Center, Department of Cell Biology, University of Connecticut Health Center, Farmington, Connecticut
| | - Albert S Yu
- Calhoun Cardiology Center, Department of Cell Biology, University of Connecticut Health Center, Farmington, Connecticut
| | - Jonathan Stock
- Calhoun Cardiology Center, Department of Cell Biology, University of Connecticut Health Center, Farmington, Connecticut
| | - Jianyang Du
- Calhoun Cardiology Center, Department of Cell Biology, University of Connecticut Health Center, Farmington, Connecticut
| | - Lixia Yue
- Calhoun Cardiology Center, Department of Cell Biology, University of Connecticut Health Center, Farmington, Connecticut
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21
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Hu Q, Wu Y, Tang J, Zheng W, Wang Q, Nahirney D, Duszyk M, Wang S, Tu JC, Chen XZ. Expression of polycystins and fibrocystin on primary cilia of lung cells. Biochem Cell Biol 2014; 92:547-54. [DOI: 10.1139/bcb-2014-0062] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
Mutations in polycystin-1, polycystin-2, or fibrocystin account for autosomal dominant or recessive polycystic kidney disease. Renal cystogenesis is linked to abnormal localization and function of these cystoproteins in renal primary cilia. They are also expressed in extrarenal tissues in which their functions are unclear. Here we found that human type-II alveolar epithelial A549, airway submucosal Calu-3 cells, and rat bronchioles contain primary or multiple cilia in which we detected these cystoproteins. At sub-confluency, polycystin-1 was expressed on plasma membrane, while polycystin-2 was localized to the ER of resting cells. Both polycystins were detected on the spindle and mid-body of mitotic cells, while fibrocystin was on centrosome throughout cell cycle. Polycystins and fibrocystin may participate in regulating mucociliary sensing and transport within pulmonary airways.
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Affiliation(s)
- Qiaolin Hu
- Membrane Protein Disease Research Group, Department of Physiology, University of Alberta, 7-29 Medical Sciences Building, Edmonton, AB T6G 2H7, Canada
| | - Yuliang Wu
- Membrane Protein Disease Research Group, Department of Physiology, University of Alberta, 7-29 Medical Sciences Building, Edmonton, AB T6G 2H7, Canada
| | - Jingfeng Tang
- Membrane Protein Disease Research Group, Department of Physiology, University of Alberta, 7-29 Medical Sciences Building, Edmonton, AB T6G 2H7, Canada
| | - Wang Zheng
- Membrane Protein Disease Research Group, Department of Physiology, University of Alberta, 7-29 Medical Sciences Building, Edmonton, AB T6G 2H7, Canada
| | - Qian Wang
- Membrane Protein Disease Research Group, Department of Physiology, University of Alberta, 7-29 Medical Sciences Building, Edmonton, AB T6G 2H7, Canada
| | - Drew Nahirney
- Membrane Protein Disease Research Group, Department of Physiology, University of Alberta, 7-29 Medical Sciences Building, Edmonton, AB T6G 2H7, Canada
| | - Marek Duszyk
- Membrane Protein Disease Research Group, Department of Physiology, University of Alberta, 7-29 Medical Sciences Building, Edmonton, AB T6G 2H7, Canada
| | - Shaohua Wang
- Department of Surgery, University of Alberta, Edmonton, AB T6G 2B7, Canada
| | - Jian-Cheng Tu
- Zhongnan Hospital, Wuhan University, Wuhan, Hubei, China
| | - Xing-Zhen Chen
- Membrane Protein Disease Research Group, Department of Physiology, University of Alberta, 7-29 Medical Sciences Building, Edmonton, AB T6G 2H7, Canada
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22
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Retailleau K, Duprat F. Polycystins and partners: proposed role in mechanosensitivity. J Physiol 2014; 592:2453-71. [PMID: 24687583 DOI: 10.1113/jphysiol.2014.271346] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Mutations of the two polycystins, PC1 and PC2, lead to polycystic kidney disease. Polycystins are able to form complexes with numerous families of proteins that have been suggested to participate in mechanical sensing. The proposed role of polycystins and their partners in the kidney primary cilium is to sense urine flow. A role for polycystins in mechanosensing has also been shown in other cell types such as vascular smooth muscle cells and cardiac myocytes. At the plasma membrane, polycystins interact with diverse ion channels of the TRP family and with stretch-activated channels (Piezos, TREKs). The actin cytoskeleton and its interacting proteins, such as filamin A, have been shown to be essential for these interactions. Numerous proteins involved in cell-cell and cell-extracellular matrix junctions interact with PC1 and/or PC2. These multimeric protein complexes are important for cell structure integrity, the transmission of force, as well as for mechanosensing and mechanotransduction. A group of polycystin partners are also involved in subcellular trafficking mechanisms. Finally, PC1 and especially PC2 interact with elements of the endoplasmic reticulum and are essential components of calcium homeostasis. In conclusion, we propose that both PC1 and PC2 act as conductors to tune the overall cellular mechanosensitivity.
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Affiliation(s)
- Kevin Retailleau
- CNRS Institute of Molecular and Cellular Pharmacology (IPMC), Valbonne, France
| | - Fabrice Duprat
- CNRS Institute of Molecular and Cellular Pharmacology (IPMC), Valbonne, France
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23
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Bogdan S, Schultz J, Grosshans J. Formin' cellular structures: Physiological roles of Diaphanous (Dia) in actin dynamics. Commun Integr Biol 2014; 6:e27634. [PMID: 24719676 PMCID: PMC3977921 DOI: 10.4161/cib.27634] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2013] [Revised: 12/21/2013] [Accepted: 12/23/2013] [Indexed: 01/06/2023] Open
Abstract
Members of the Diaphanous (Dia) protein family are key regulators of fundamental actin driven cellular processes, which are conserved from yeast to humans. Researchers have uncovered diverse physiological roles in cell morphology, cell motility, cell polarity, and cell division, which are involved in shaping cells into tissues and organs. The identification of numerous binding partners led to substantial progress in our understanding of the differential functions of Dia proteins. Genetic approaches and new microscopy techniques allow important new insights into their localization, activity, and molecular principles of regulation.
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Affiliation(s)
- Sven Bogdan
- Institut für Neurobiologie; Universität Münster; Münster, Germany
| | - Jörg Schultz
- Bioinformatik, Biozentrum; Universität Würzburg; Würzburg, Germany
| | - Jörg Grosshans
- Institut für Biochemie; Universitätsmedizin; Universität Göttingen; Göttingen, Germany
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24
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Abstract
It has been exciting times since the identification of polycystic kidney disease 1 (PKD1) and PKD2 as the genes mutated in autosomal dominant polycystic kidney disease (ADPKD). Biological roles of the encoded proteins polycystin-1 and TRPP2 have been deduced from phenotypes in ADPKD patients, but recent insights from vertebrate and invertebrate model organisms have significantly expanded our understanding of the physiological functions of these proteins. The identification of additional TRPP (TRPP3 and TRPP5) and polycystin-1-like proteins (PKD1L1, PKD1L2, PKD1L3, and PKDREJ) has added yet another layer of complexity to these fascinating cellular signalling units. TRPP proteins assemble with polycystin-1 family members to form receptor-channel complexes. These protein modules have important biological roles ranging from tubular morphogenesis to determination of left-right asymmetry. The founding members of the polycystin family, TRPP2 and polycystin-1, are a prime example of how studying human disease genes can provide insights into fundamental biological mechanisms using a so-called "reverse translational" approach (from bedside to bench). Here, we discuss the current literature on TRPP ion channels and polycystin-1 family proteins including expression, structure, physical interactions, physiology, and lessons from animal model systems and human disease.
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Affiliation(s)
- Mariam Semmo
- Renal Division, Department of Medicine, University Medical Centre Freiburg, Hugstetter Straße 55, 79106, Freiburg, Germany,
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25
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Cvrčková F. Formins and membranes: anchoring cortical actin to the cell wall and beyond. FRONTIERS IN PLANT SCIENCE 2013; 4:436. [PMID: 24204371 PMCID: PMC3817587 DOI: 10.3389/fpls.2013.00436] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/18/2013] [Accepted: 10/13/2013] [Indexed: 05/03/2023]
Abstract
Formins are evolutionarily conserved eukaryotic proteins participating in actin and microtubule organization. Land plants have three formin clades, with only two - Class I and II - present in angiosperms. Class I formins are often transmembrane proteins, residing at the plasmalemma and anchoring the cortical cytoskeleton across the membrane to the cell wall, while Class II formins possess a PTEN-related membrane-binding domain. Lower plant Class III and non-plant formins usually contain domains predicted to bind RHO GTPases that are membrane-associated. Thus, some kind of membrane anchorage appears to be a common formin feature. Direct interactions between various non-plant formins and integral or peripheral membrane proteins have indeed been reported, with varying mechanisms and biological implications. Besides of summarizing new data on Class I and Class II formin-membrane relationships, this review surveys such "non-classical" formin-membrane interactions and examines which, if any, of them may be evolutionarily conserved and operating also in plants. FYVE, SH3 and BAR domain-containing proteins emerge as possible candidates for such conserved membrane-associated formin partners.
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Affiliation(s)
- Fatima Cvrčková
- *Correspondence: Fatima Cvrčková, Department of Experimental Plant Biology, Faculty of Science, Charles University, Viničná 5, CZ 128 43, Prague, Czech Republic e-mail:
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26
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Streets AJ, Wessely O, Peters DJM, Ong ACM. Hyperphosphorylation of polycystin-2 at a critical residue in disease reveals an essential role for polycystin-1-regulated dephosphorylation. Hum Mol Genet 2013; 22:1924-39. [PMID: 23390129 DOI: 10.1093/hmg/ddt031] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
Mutations in PKD1 (85%) or PKD2 (15%) account for almost all cases of autosomal dominant polycystic kidney disease (ADPKD). The ADPKD proteins, termed as polycystin-1 (PC1) and polycystin-2 (PC2), interact via their C-termini to form a receptor-ion channel complex whose function and regulation are not fully understood. Here, we report the first phosphorylated residue (Ser(829)) in PC2, whose dephosphorylation is mediated by PC1 binding through the recruitment of protein phosphatase-1 alpha (PP1α). Using a new phosphospecific antibody (pPC2) to this site, we demonstrate that Ser(829) is phosphorylated by Protein kinase A (PKA) but remains constitutively phosphorylated in cells and tissues lacking PC1. cAMP increased pSer(829) basolateral localization in MDCK cells in a time dependent manner and was essential for pronephric development in Xenopus embryos. When constitutively expressed, a complex phenotype associated with enhanced ATP-dependent ER Ca(2+) release and loss of growth suppression was observed in cycling cells. These results reveal a reciprocal functional link between PC1 and PC2 which is critically dependent on their interaction. Unopposed cAMP stimulated hyperphosphorylation of PC2 in the absence of functional PC1 could contribute to cyst initiation in PKD1 patients and represents a new molecular paradigm in understanding ADPKD pathogenesis.
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Affiliation(s)
- Andrew J Streets
- Kidney Genetics Group, Academic Nephrology Unit, Henry Wellcome Laboratories for Medical Research,University of Sheffield Medical School, Sheffield, UK
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27
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Abstract
mDia proteins are members of the formin family of actin nucleating proteins that polymerize linear actin filaments. Such filaments form the core of thin, tubular, membrane-bound cell surface protrusions known as filopodia, which are a major feature of mammalian cell morphology. Filopodia are dynamic structures that help cells sense environmental cues, and play a role in cell migration, axon guidance, angiogenesis and other processes. RhoGTPases bind to and control the activity of mDia proteins, and several other binding partners of the three mDia1 isoforms-mDia1, mDia2 and mDia3-have been documented. Two independent pathways controlling mammalian filopodium formation have emerged, with one driven by the RhoGTPase Cdc42, and the other by Rif. While mDia2 has been the main formin implicated in forming filopodia, mDia1 has recently surfaced as the key formin utilized by both the Cdc42 and Rif pathways to drive filopodial protrusion.
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Affiliation(s)
- Wah Ing Goh
- Institute of Medical Biology; Singapore; Immunos, Singapore
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28
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Bartolini F, Ramalingam N, Gundersen GG. Actin-capping protein promotes microtubule stability by antagonizing the actin activity of mDia1. Mol Biol Cell 2012; 23:4032-40. [PMID: 22918941 PMCID: PMC3469518 DOI: 10.1091/mbc.e12-05-0338] [Citation(s) in RCA: 55] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Actin-capping protein induced stable microtubules in an mDia1-dependent manner and inhibited the translocation of mDia on the ends of growing actin filaments. Knockdown of capping protein by small interfering RNA reduced stable microtubule levels in proliferating cells and in starved cells stimulated with lysophosphatidic acid. In migrating fibroblasts, RhoA and its effector mDia1 regulate the selective stabilization of microtubules (MTs) polarized in the direction of migration. The conserved formin homology 2 domain of mDia1 is involved both in actin polymerization and MT stabilization, and the relationship between these two activities is unknown. We found that latrunculin A (LatA) and jasplakinolide, actin drugs that release mDia1 from actin filament barbed ends, stimulated stable MT formation in serum-starved fibroblasts and caused a redistribution of mDia1 onto MTs. Knockdown of mDia1 by small interfering RNA (siRNA) prevented stable MT induction by LatA, whereas blocking upstream Rho or integrin signaling had no effect. In search of physiological regulators of mDia1, we found that actin-capping protein induced stable MTs in an mDia1-dependent manner and inhibited the translocation of mDia on the ends of growing actin filaments. Knockdown of capping protein by siRNA reduced stable MT levels in proliferating cells and in starved cells stimulated with lysophosphatidic acid. These results show that actin-capping protein is a novel regulator of MT stability that functions by antagonizing mDia1 activity toward actin filaments and suggest a novel form of actin–MT cross-talk in which a single factor acts sequentially on actin and MTs.
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Affiliation(s)
- Francesca Bartolini
- Department of Pathology and Cell Biology, Columbia University, New York, NY 10032, USA
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29
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Lee K, Battini L, Gusella GL. Cilium, centrosome and cell cycle regulation in polycystic kidney disease. Biochim Biophys Acta Mol Basis Dis 2011; 1812:1263-71. [PMID: 21376807 DOI: 10.1016/j.bbadis.2011.02.008] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2010] [Revised: 01/10/2011] [Accepted: 02/16/2011] [Indexed: 12/19/2022]
Abstract
Polycystic kidney disease is the defining condition of a group of common life-threatening genetic disorders characterized by the bilateral formation and progressive expansion of renal cysts that lead to end stage kidney disease. Although a large body of information has been acquired in the past years about the cellular functions that characterize the cystic cells, the mechanisms triggering the cystogenic conversion are just starting to emerge. Recent findings link defects in ciliary functions, planar cell polarity pathway, and centrosome integrity in early cystic development. Many of the signals dysregulated during cystogenesis may converge on the centrosome for its central function as a structural support for cilia formation and a coordinator of protein trafficking, polarity, and cell division. Here, we will discuss the contribution of proliferation, cilium and planar cell polarity to the cystic signal and will analyze in particular the possible role that the basal bodies/centrosome may play in the cystogenetic mechanisms. This article is part of a Special Issue entitled: Polycystic Kidney Disease.
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Affiliation(s)
- Kyung Lee
- Department of Medicine, The Mount Sinai School of Medicine, New York, NY, USA
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30
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Gene expression profiling of oral squamous cell carcinoma by differential display rt-PCR and identification of tumor biomarkers. Indian J Surg Oncol 2011; 1:284-93. [PMID: 22693380 DOI: 10.1007/s13193-011-0054-x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2010] [Accepted: 01/31/2011] [Indexed: 01/05/2023] Open
Abstract
Oral squamous cell carcinoma (OSCC) is the sixth most common cancer worldwide. Despite progress in therapeutic and surgical treatments, its survival period at 5 years is the lowest among major cancers, and remains unchanged in the last two decades. The growing epidemiological relevance of oral cancer emphasizes the need to better understand the molecular mechanisms underlying this disease and identify predictive tumor markers and therapeutic targets. To this end, we have used the DDRT-PCR analysis to profile the oral tumor transcriptome and identify differentially regulated genes that may be used as potential biomarkers and therapeutic targets. Our DDRT-PCR analysis identified 51 differentially expressed fragments, of which 25 were revalidated by reverse Northern analysis. Northern blot analysis further corroborated these findings for a few genes. In order to ascertain the utility of some of the identified genes as molecular markers and therapeutic targets, semi-quantitative RT-PCR analysis was carried out in a panel of matched oral normal and tumor samples, that confirmed GLTP, PCNA, RBM28, C17orf75 and DIAPH1 as significantly upregulated, whereas TNKS2, PAM and TUBB2C showed significant downregulation in tumor samples. Taken together, our DDRT-PCR analysis has revealed several genes, belonging to diverse cellular pathways, that have been associated with OSCC for the first time. Thus, these genes could be investigated as biomarkers and therapeutic targets for OSCC.
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Wang Q, Yin H, He J, Ye J, Ding F, Wang S, Hu X, Meng Q, Li N. cDNA cloning of porcine PKD2 gene and RNA interference in LLC-PK1 cells. Gene 2011; 476:38-45. [PMID: 21277361 DOI: 10.1016/j.gene.2011.01.017] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2010] [Revised: 01/11/2011] [Accepted: 01/24/2011] [Indexed: 11/16/2022]
Abstract
Mutations in the PKD2 gene cause autosomal dominant polycystic kidney disease (ADPKD), a common, inherited disease that frequently leads to end-stage renal disease (ESRD). Swine show substantial similarity to humans physiologically and anatomically, and are therefore a good model system in which to decipher the structure and function of the PKD2 gene and to identify potential therapeutic targets. Here we report the cloning and characterization of the porcine PKD2 cDNA showing that the full-length gene (3370 bases) is highly expressed in kidney, with minimal expression in the liver. RNA interference (RNAi) is a promising tool to enable identification of the essential components necessary for exploitation of the pathway involved in cellular processes. We therefore designed four shRNAs and nine siRNAs targeting the region of the porcine PKD2 gene from exons 3 to 9, which is supposed to be a critical region contributing to the severity of ADPKD. The results from HeLa cells with the dual-luciferase reporter system and porcine kidney cells (LLC-PK1) showed that sh12 could efficiently knock down the PKD2 gene with an efficiency of 51% and P1 and P2 were the most effective siRNAs inhibiting 85% and 77% respectively of PKD2 expression compared with untreated controls. A subsequent functional study of the transient receptor potential polycystic (TRPP) 2 channel protein indicated that the decreased expression of TRPP2 induced by siRNA P1 and P2 could release the arrest of the cell cycle from G0/G1 promoting progression to S and G2 phases. Our data, therefore, provides evidence of potential knock-down target sites in the PKD2 gene and paves the way for the future generation of transgenic ADPKD knock-down animal models.
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Affiliation(s)
- Qingsong Wang
- Tianjin Research Centre of Basic Medical Science, Tianjin Medical University, Qixiangtai Road, Heping District, Tianjin, 300070, China
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Sharma N, Kosan ZA, Stallworth JE, Berbari NF, Yoder BK. Soluble levels of cytosolic tubulin regulate ciliary length control. Mol Biol Cell 2011; 22:806-16. [PMID: 21270438 PMCID: PMC3057705 DOI: 10.1091/mbc.e10-03-0269] [Citation(s) in RCA: 130] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
We show that manipulation of either the microtubule or the actin cytoskeleton has unexpected influences on cilia length control. The primary cilium is an evolutionarily conserved dynamic organelle important for regulating numerous signaling pathways, and, as such, mutations disrupting ciliogenesis result in a variety of developmental abnormalities and postnatal disorders. The length of the cilium is regulated by the cell through largely unknown mechanisms. Normal cilia length is important, as either shortened or elongated cilia have been associated with disease and developmental defects. Here we explore the importance of cytoskeletal dynamics in regulating cilia length. Using pharmacological approaches in different cell types, we demonstrate that actin depolymerization or stabilization and protein kinase A activation result in a rapid elongation of the primary cilium. The effects of pharmacological agents on cilia length are associated with a subsequent increase in soluble tubulin levels and can be impaired by depletion of soluble tubulin with taxol. In addition, subtle nocodazole treatment was able to induce ciliogenesis under conditions in which cilia are not normally formed and also increases cilia length on cells that have already established cilia. Together these data indicate that cilia length can be regulated through changes in either the actin or microtubule network and implicate a possible role for soluble tubulin levels in cilia length control.
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Affiliation(s)
- Neeraj Sharma
- Department of Cell Biology, School of Medicine, University of Alabama at Birmingham, Birmingham, AL 35294, USA
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33
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Abstract
Polycystic kidney disease is a common genetic disorder in which fluid-filled cysts displace normal renal tubules. Here we focus on autosomal dominant polycystic kidney disease, which is attributable to mutations in the PKD1 and PKD2 genes and which is characterized by perturbations of renal epithelial cell growth control, fluid transport, and morphogenesis. The mechanisms that connect the underlying genetic defects to disease pathogenesis are poorly understood, but their exploration is shedding new light on interesting cell biological processes and suggesting novel therapeutic targets.
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Affiliation(s)
- Hannah C Chapin
- Department of Cellular and Molecular Physiology, Yale University School of Medicine, New Haven, CT 06520, USA
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Abstract
The founding member of the TRPP family, TRPP2, was identified as one of the disease genes causing autosomal dominant polycystic kidney disease (ADPKD). ADPKD is the most prevalent, potentially lethal, monogenic disorder in humans, with an average incidence of one in 400 to one in 1,000 individuals worldwide. Here we give an overview of TRPP ion channels and Polycystin-1 receptor proteins focusing on more recent studies. We include the Polycystin-1 family since these proteins are functionally linked to TRPP channels.
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Kwon S, Shin H, Lim HJ. Dynamic interaction of formin proteins and cytoskeleton in mouse oocytes during meiotic maturation. Mol Hum Reprod 2010; 17:317-27. [DOI: 10.1093/molehr/gaq088] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Epidermal growth factor-mediated proliferation and sodium transport in normal and PKD epithelial cells. Biochim Biophys Acta Mol Basis Dis 2010; 1812:1301-13. [PMID: 20959142 DOI: 10.1016/j.bbadis.2010.10.004] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2010] [Revised: 09/30/2010] [Accepted: 10/11/2010] [Indexed: 02/07/2023]
Abstract
Members of the epidermal growth factor (EGF) family bind to ErbB (EGFR) family receptors which play an important role in the regulation of various fundamental cell processes including cell proliferation and differentiation. The normal rodent kidney has been shown to express at least three members of the ErbB receptor family and is a major site of EGF ligand synthesis. Polycystic kidney disease (PKD) is a group of diseases caused by mutations in single genes and is characterized by enlarged kidneys due to the formation of multiple cysts in both kidneys. Tubule cells proliferate, causing segmental dilation, in association with the abnormal deposition of several proteins. One of the first abnormalities described in cell biological studies of PKD pathogenesis was the abnormal mislocalization of the EGFR in cyst lining epithelial cells. The kidney collecting duct (CD) is predominantly an absorptive epithelium where electrogenic Na(+) entry is mediated by the epithelial Na(+) channel (ENaC). ENaC-mediated sodium absorption represents an important ion transport pathway in the CD that might be involved in the development of PKD. A role for EGF in the regulation of ENaC-mediated sodium absorption has been proposed. However, several investigations have reported contradictory results indicating opposite effects of EGF and its related factors on ENaC activity and sodium transport. Recent advances in understanding how proteins in the EGF family regulate the proliferation and sodium transport in normal and PKD epithelial cells are discussed here. This article is part of a Special Issue entitled: Polycystic Kidney Disease.
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Gees M, Colsoul B, Nilius B. The role of transient receptor potential cation channels in Ca2+ signaling. Cold Spring Harb Perspect Biol 2010; 2:a003962. [PMID: 20861159 DOI: 10.1101/cshperspect.a003962] [Citation(s) in RCA: 308] [Impact Index Per Article: 22.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
The 28 mammalian members of the super-family of transient receptor potential (TRP) channels are cation channels, mostly permeable to both monovalent and divalent cations, and can be subdivided into six main subfamilies: the TRPC (canonical), TRPV (vanilloid), TRPM (melastatin), TRPP (polycystin), TRPML (mucolipin), and the TRPA (ankyrin) groups. TRP channels are widely expressed in a large number of different tissues and cell types, and their biological roles appear to be equally diverse. In general, considered as polymodal cell sensors, they play a much more diverse role than anticipated. Functionally, TRP channels, when activated, cause cell depolarization, which may trigger a plethora of voltage-dependent ion channels. Upon stimulation, Ca2+ permeable TRP channels generate changes in the intracellular Ca2+ concentration, [Ca2+]i, by Ca2+ entry via the plasma membrane. However, more and more evidence is arising that TRP channels are also located in intracellular organelles and serve as intracellular Ca2+ release channels. This review focuses on three major tasks of TRP channels: (1) the function of TRP channels as Ca2+ entry channels; (2) the electrogenic actions of TRPs; and (3) TRPs as Ca2+ release channels in intracellular organelles.
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Affiliation(s)
- Maarten Gees
- KU Leuven, Department of Molecular Cell Biology, Laboratory Ion Channel Research, Campus Gasthuisberg, Herestraat 49, bus 802, Leuven, Belgium
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Hurd T, Zhou W, Jenkins P, Liu CJ, Swaroop A, Khanna H, Martens J, Hildebrandt F, Margolis B. The retinitis pigmentosa protein RP2 interacts with polycystin 2 and regulates cilia-mediated vertebrate development. Hum Mol Genet 2010; 19:4330-44. [PMID: 20729296 DOI: 10.1093/hmg/ddq355] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
Ciliopathies represent a growing group of human genetic diseases whose etiology lies in defects in ciliogenesis or ciliary function. Given the established entity of renal-retinal ciliopathies, we have been examining the role of cilia-localized proteins mutated in retinitis pigmentosa (RP) in regulating renal ciliogenesis or cilia-dependent signaling cascades. Specifically, this study examines the role of the RP2 gene product with an emphasis on renal and vertebrate development. We demonstrate that in renal epithelia, RP2 localizes to the primary cilium through dual acylation of the amino-terminus. We also show that RP2 forms a calcium-sensitive complex with the autosomal dominant polycystic kidney disease protein polycystin 2. Ablation of RP2 by shRNA promotes swelling of the cilia tip that may be a result of aberrant trafficking of polycystin 2 and other ciliary proteins. Morpholino-mediated repression of RP2 expression in zebrafish results in multiple developmental defects that have been previously associated with ciliary dysfunction, such as hydrocephalus, kidney cysts and situs inversus. Finally, we demonstrate that, in addition to our observed physical interaction between RP2 and polycystin 2, dual morpholino-mediated knockdown of polycystin 2 and RP2 results in enhanced situs inversus, indicating that these two genes also regulate a common developmental process. This work suggests that RP2 may be an important regulator of ciliary function through its association with polycystin 2 and provides evidence of a further link between retinal and renal cilia function.
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Affiliation(s)
- Toby Hurd
- Department of Pediatrics and Communicable Diseases, University of Michigan, 1150 West Medical Center Drive, Ann Arbor, MI 48109, USA.
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Zhang J, Wu M, Wang S, Shah JV, Wilson PD, Zhou J. Polycystic kidney disease protein fibrocystin localizes to the mitotic spindle and regulates spindle bipolarity. Hum Mol Genet 2010; 19:3306-19. [PMID: 20554582 DOI: 10.1093/hmg/ddq233] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Autosomal recessive polycystic kidney disease (ARPKD) is a significant hereditary renal disease occurring in infancy and childhood, which presents with greatly enlarged echogenic kidneys, ultimately leading to renal insufficiency and end-stage renal disease. ARPKD is caused by mutations in a single gene PKHD1, which encodes fibrocystin/polyductin (FPC), a large single transmembrane protein generally known to be on the primary cilium, basal body and plasma membrane. Here, using our newly generated antibody raised against the entire C-terminal intracellular cytoplasmic domain (ICD) of FPC, as well as our previously well-characterized antibody against a peptide of ICD, we report for the first time that at least one isoform of FPC is localized to the centrosome and mitotic spindle of dividing cells in multiple cell lines, including MDCK, mIMCD3, LLC-PK1, HEK293, RCTEC and HFCT cells. Using short-hairpin-mediated RNA interference, we show that the inhibition of FPC function in MDCK and mIMCD3 cells leads to centrosome amplification, chromosome lagging and multipolar spindle formation. Consistent with our in vitro findings, we also observed centrosome amplification in the kidneys from human ARPKD patients. These findings demonstrate a novel function of FPC in centrosome duplication and mitotic spindle assembly during cell division. We propose that mitotic defects due to FPC dysfunction contribute to cystogenesis in ARPKD.
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Affiliation(s)
- Jingjing Zhang
- Renal Division, Department of Medicine, Room 522, Harvard Institute of Medicine, 4 Blackfan Circle, Boston, MA 02115, USA
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40
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Basora N, Tétreault MP, Boucher MP, Herring E, Beaulieu JF. Polycystin-1 is a microtubule-driven desmosome-associated component in polarized epithelial cells. Exp Cell Res 2010; 316:1454-64. [PMID: 20211617 DOI: 10.1016/j.yexcr.2010.02.033] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2006] [Revised: 02/25/2010] [Accepted: 02/26/2010] [Indexed: 11/16/2022]
Abstract
In this study, we have analyzed the expression and localization of polycystin-1 in intestinal epithelial cells, a system lacking primary cilia. Polycystin-1 was found to be expressed in the epithelium of the small intestine during development and levels remained elevated in the adult. Dual-labelling indirect immunofluorescence revealed polycystin-1 at sites of cell-cell contact co-localizing with the desmosomes both in situ as well as in polarized Caco-2/15 cells. In unpolarized cultures of Caco-2/15 cells, polycystin-1 was recruited to the cell surface early during initiation of cell junction assembly. In isolated Caco-2/15 cells and HIEC-6 cell cultures, where junctional complexes are absent, polycystin-1 was found predominantly associated with the cytoskeletal elements of the intermediate filaments and microtubule networks. More precisely, polycystin-1 was seen as brightly labelled puncta decorating the keratin-18 positive filaments as well as the beta-tubulin positive microtubules, which was particularly obvious in the lamellipodia. Treatment with the microtubule-disrupting agent, nocodazole, eliminated the microtubule association of polycystin-1 but did not seem to affect its association with keratin or the desmosomes. Taken together these data suggest that polycystin-1 is involved with the establishment of cell-cell junctions in absorptive intestinal epithelial cells and exploits the microtubule-based machinery in order to be transported to the plasma membrane.
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Affiliation(s)
- Nuria Basora
- Department of Anatomy and Cell Biology, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Sherbrooke, Québec, Canada.
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Xia S, Li X, Johnson T, Seidel C, Wallace DP, Li R. Polycystin-dependent fluid flow sensing targets histone deacetylase 5 to prevent the development of renal cysts. Development 2010; 137:1075-84. [PMID: 20181743 DOI: 10.1242/dev.049437] [Citation(s) in RCA: 75] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Polycystin 1 and polycystin 2 are large transmembrane proteins, which, when mutated, cause autosomal dominant polycystic kidney disease (ADPKD), a highly prevalent human genetic disease. The polycystins are thought to form a receptor-calcium channel complex in the plasma membrane of renal epithelial cells and elicit a calcium influx in response to mechanical stimulation, such as fluid flow across the apical surface of renal epithelial cells. The functional role of the polycystins in mechanosensation remains largely unknown. Here, we found that myocyte enhancer factor 2C (MEF2C) and histone deacetylase 5 (HDAC5), two key regulators of cardiac hypertrophy, are targets of polycystin-dependent fluid stress sensing in renal epithelial cells in mice. We show that fluid flow stimulation of polarized epithelial monolayers induced phosphorylation and nuclear export of HDAC5, which are crucial events in the activation of MEF2C-based transcription. Kidney-specific knockout of Mef2c, or genetrap-inactivation of a MEF2C transcriptional target, MIM, resulted in extensive renal tubule dilation and cysts, whereas Hdac5 heterozygosity or treatment with TSA, an HDAC inhibitor, reduced cyst formation in Pkd2(-/-) mouse embryos. These findings suggest a common signaling motif between myocardial hypertrophy and maintenance of renal epithelial architecture, and a potential therapeutic approach to treat ADPKD.
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Affiliation(s)
- Sheng Xia
- The Stowers Institute for Medical Research, 1000 East 50th Street, Kansas City, MO 64110, USA
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42
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Requirement for formin-induced actin polymerization during spread of Shigella flexneri. Infect Immun 2009; 78:193-203. [PMID: 19841078 DOI: 10.1128/iai.00252-09] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
Actin polymerization in the cytosol and at the plasma membrane is locally regulated by actin nucleators. Several microbial pathogens exploit cellular actin polymerization to spread through tissue. The movement of the enteric pathogen Shigella flexneri, both within the cell body and from cell to cell, depends on actin polymerization. During intercellular spread, actin polymerization at the bacterial surface generates protrusions of the plasma membrane, which are engulfed by adjacent cells. In the cell body, polymerization of actin by Shigella spp. is dependent on N-WASP activation of the Arp2/Arp3 complex. Here we demonstrate that, in contrast, efficient protrusion formation and intercellular spread depend on actin polymerization that involves activation of the Diaphanous formin Dia. While the Shigella virulence protein IpgB2 can bind and activate Dia1 (N. M. Alto et al., Cell 124:133-145, 2006), its absence does not result in a detectable defect in Dia-dependent protrusion formation or spread. The dependence on the activation of Dia during S. flexneri infection contrasts with the inhibition of this pathway observed during vaccinia virus infection.
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Miyagi K, Kiyonaka S, Yamada K, Miki T, Mori E, Kato K, Numata T, Sawaguchi Y, Numaga T, Kimura T, Kanai Y, Kawano M, Wakamori M, Nomura H, Koni I, Yamagishi M, Mori Y. A pathogenic C terminus-truncated polycystin-2 mutant enhances receptor-activated Ca2+ entry via association with TRPC3 and TRPC7. J Biol Chem 2009; 284:34400-12. [PMID: 19812035 DOI: 10.1074/jbc.m109.015149] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Mutations in PKD2 gene result in autosomal dominant polycystic kidney disease (ADPKD). PKD2 encodes polycystin-2 (TRPP2), which is a homologue of transient receptor potential (TRP) cation channel proteins. Here we identify a novel PKD2 mutation that generates a C-terminal tail-truncated TRPP2 mutant 697fsX with a frameshift resulting in an aberrant 17-amino acid addition after glutamic acid residue 697 from a family showing mild ADPKD symptoms. When recombinantly expressed in HEK293 cells, wild-type (WT) TRPP2 localized at the endoplasmic reticulum (ER) membrane significantly enhanced Ca(2+) release from the ER upon muscarinic acetylcholine receptor (mAChR) stimulation. In contrast, 697fsX, which showed a predominant plasma membrane localization characteristic of TRPP2 mutants with C terminus deletion, prominently increased mAChR-activated Ca(2+) influx in cells expressing TRPC3 or TRPC7. Coimmunoprecipitation, pulldown assay, and cross-linking experiments revealed a physical association between 697fsX and TRPC3 or TRPC7. 697fsX but not WT TRPP2 elicited a depolarizing shift of reversal potentials and an enhancement of single-channel conductance indicative of altered ion-permeating pore properties of mAChR-activated currents. Importantly, in kidney epithelial LLC-PK1 cells the recombinant 679fsX construct was codistributed with native TRPC3 proteins at the apical membrane area, but the WT construct was distributed in the basolateral membrane and adjacent intracellular areas. Our results suggest that heteromeric cation channels comprised of the TRPP2 mutant and the TRPC3 or TRPC7 protein induce enhanced receptor-activated Ca(2+) influx that may lead to dysregulated cell growth in ADPKD.
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Affiliation(s)
- Kyoko Miyagi
- Department of Synthetic Chemistry and Biological Chemistry, Graduate School of Engineering, Kyoto University, Japan
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Bartolini F, Gundersen GG. Formins and microtubules. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2009; 1803:164-73. [PMID: 19631698 DOI: 10.1016/j.bbamcr.2009.07.006] [Citation(s) in RCA: 135] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/02/2009] [Revised: 05/29/2009] [Accepted: 07/04/2009] [Indexed: 02/06/2023]
Abstract
Formins have recently been recognized as prominent regulators of the microtubule (MT) cytoskeleton where they modulate the dynamics of selected MTs in interphase and mitosis. The association of formins with the MT cytoskeleton and their action on MT dynamics are relatively unexplored areas, yet growing evidence supports a direct role in their regulation of MT stability independent of their activity on actin. Formins regulate MT stability alone or in combination with accessory MT binding proteins that have previously been implicated in the stabilization of MTs downstream of polarity cues. As actin and MT arrays are typically remodeled downstream of signaling pathways that orchestrate cell shape and division, formins are emerging as excellent candidates for coordinating the responses of the cytoskeletal in diverse regulated and homeostatic processes.
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Affiliation(s)
- F Bartolini
- Department of Pathology and Cell Biology, Columbia University, New York, NY, USA
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45
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Aspenström P. Formin-binding proteins: modulators of formin-dependent actin polymerization. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2009; 1803:174-82. [PMID: 19589360 DOI: 10.1016/j.bbamcr.2009.06.002] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/01/2008] [Revised: 06/22/2009] [Accepted: 06/26/2009] [Indexed: 12/27/2022]
Abstract
Formins represent a major branch of actin nucleators along with the Arp2/3 complex, Spire and Cordon-bleu. Formin-mediated actin nucleation requires the formin homology 2 domain and, although the nucleation per se does not require additional factors, formin-binding proteins have been shown to be essential for the regulation of formin-dependent actin assembly in vivo. This regulation could be accomplished by formin-binding proteins being directly involved in formin-driven actin nucleation, by formin-binding proteins influencing the activated state of the formins, by linking formin-driven actin polymerization to Arp2/3 driven actin polymerization, or by influencing the subcellular localization of the formins. This review article will focus on mammalian formin-binding proteins and their roles during vital cellular processes, such as cell migration, cell division and intracellular trafficking.
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Affiliation(s)
- Pontus Aspenström
- Department of Microbiology, Tumor and Cell Biology, Karolinska Institute, Box 280, Nobels väg 16, SE-171 77 Stockholm, Sweden.
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46
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Di Vizio D, Kim J, Hager MH, Morello M, Yang W, Lafargue CJ, True LD, Rubin MA, Adam RM, Beroukhim R, Demichelis F, Freeman MR. Oncosome formation in prostate cancer: association with a region of frequent chromosomal deletion in metastatic disease. Cancer Res 2009; 69:5601-9. [PMID: 19549916 DOI: 10.1158/0008-5472.can-08-3860] [Citation(s) in RCA: 296] [Impact Index Per Article: 19.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Oncosomes have recently been described as membrane-derived microvesicles secreted by cancer cells, which transfer oncogenic signals and protein complexes across cell boundaries. Here, we show the rapid formation and secretion of oncosomes from DU145 and LNCaP human prostate cancer cells. Oncosome formation was stimulated by epidermal growth factor receptor activation and also by overexpression of membrane-targeted Akt1. Microvesicles shed from prostate cancer cells contained numerous signal transduction proteins and were capable of activating rapid phospho-tyrosine and Akt pathway signaling, and stimulating proliferation and migration, in recipient tumor cells. They also induced a stromal reaction in recipient normal cells. Knockdown of the actin nucleating protein Diaphanous Related Formin 3 (DRF3/Dia2) by RNA interference enhanced rates of oncosome formation, indicating that these structures resemble, and may be identical to, nonapoptotic membrane blebs, a feature of the amoeboid form of cell motility. Analysis of primary and metastatic human prostate tumors using 100K single nucleotide polymorphism arrays revealed a significantly higher frequency of deletion of the locus encoding DRF3 (DIAPH3) in metastatic tumors (P = 0.001) in comparison with organ-confined tumors. Fluorescence in situ hybridization confirmed increased chromosomal loss of DIAPH3 in metastatic tumors in a different cohort of patients (P = 0.006). These data suggest that microvesicles shed from prostate cancer cells can alter the tumor microenvironment in a manner that may promote disease progression. They also show that DRF3 is a physiologically relevant protein that seems to regulate this process.
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Affiliation(s)
- Dolores Di Vizio
- The Urological Diseases Research Center, Children's Hospital Boston, Boston, MA 02115, USA
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47
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Affiliation(s)
- Jing Zhou
- Renal Division, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts 02115;
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48
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Tsiokas L. Function and regulation of TRPP2 at the plasma membrane. Am J Physiol Renal Physiol 2009; 297:F1-9. [PMID: 19244406 DOI: 10.1152/ajprenal.90277.2008] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
The vast majority (approximately 99%) of all known cases of autosomal dominant polycystic kidney disease (ADPKD) are caused by naturally occurring mutations in two separate, but genetically interacting, loci, pkd1 and pkd2. pkd1 encodes a large multispanning membrane protein (PKD1) of unknown function, while pkd2 encodes a protein (TRPP2, polycystin-2, or PKD2) of the transient receptor potential (TRP) superfamily of ion channels. Biochemical, functional, and genetic studies support a model in which PKD1 physically interacts with TRPP2 to form an ion channel complex that conveys extracellular stimuli to ionic currents. However, the molecular identity of these extracellular stimuli remains elusive. Functional studies in cell culture show that TRPP2 can be activated in response to mechanical cues (fluid shear stress) and/or receptor tyrosine kinase (RTK) and G protein-coupled receptor (GPCR) activation at the cell surface. Recent genetic studies in Chlamydomonas reinhardtii show that CrPKD2 functions in a pathway linking cell-cell adhesion and Ca(2+) signaling. The mode of activation depends on protein-protein interactions with other channel subunits and auxiliary proteins. Therefore, understanding the mechanisms underlying the molecular makeup of TRPP2-containing complexes is critical in delineating the mechanisms of TRPP2 activation and, most importantly, the mechanisms by which naturally occurring mutations in pkd1 or pkd2 lead not only to ADPKD, but also to other defects reported in model organisms lacking functional TRPP2. This review focuses on the molecular assembly, function, and regulation of TRPP2 as a cell surface cation channel and discusses its potential role in Ca(2+) signaling and ADPKD pathophysiology.
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Affiliation(s)
- Leonidas Tsiokas
- Department of Cell Biology, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA.
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A short carboxy-terminal domain of polycystin-1 reorganizes the microtubular network and the endoplasmic reticulum. Exp Cell Res 2009; 315:1157-70. [PMID: 19331813 DOI: 10.1016/j.yexcr.2009.01.027] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2008] [Revised: 01/23/2009] [Accepted: 01/28/2009] [Indexed: 11/21/2022]
Abstract
Mutations of PKD1 cause autosomal dominant polycystic kidney disease (ADPKD), a syndrome characterized by kidney cysts and progressive renal failure. Polycystin-1, the protein encoded by PKD1, is a large integral membrane protein with a short carboxy-terminal cytoplasmic domain that appears to initiate multiple cellular programs. We report now that this polycystin-1 domain contains a novel motif responsible for rearrangements of intermediate filaments, microtubules and the endoplasmic reticulum (ER). This motif reveals homology to CLIMP-63, a microtubule-binding protein that rearranges the ER. Our findings suggest that polycystin-1 influences the shape and localization of both the microtubular network and the ER.
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Park EY, Sung YH, Yang MH, Noh JY, Park SY, Lee TY, Yook YJ, Yoo KH, Roh KJ, Kim I, Hwang YH, Oh GT, Seong JK, Ahn C, Lee HW, Park JH. Cyst formation in kidney via B-Raf signaling in the PKD2 transgenic mice. J Biol Chem 2008; 284:7214-22. [PMID: 19098310 DOI: 10.1074/jbc.m805890200] [Citation(s) in RCA: 67] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
The pathogenic mechanisms of human autosomal dominant polycystic kidney disease (ADPKD) have been well known to include the mutational inactivation of PKD2. Although haploinsufficiency and loss of heterozygosity at the Pkd2 locus can cause cyst formation in mice, polycystin-2 is frequently expressed in the renal cyst of human ADPKD, raising the possibility that deregulated activation of PKD2 may be associated with the cystogenesis of human ADPKD. To determine whether increased PKD2 expression is physiologically pathogenic, we generated PKD2-overexpressing transgenic mice. These mice developed typical renal cysts and an increase of proliferation and apoptosis, which are reflective of the human ADPKD phenotype. These manifestations were first observed at six months, and progressed with age. In addition, we found that ERK activation was induced by PKD2 overexpression via B-Raf signaling, providing a possible molecular mechanism of cystogenesis. In PKD2 transgenic mice, B-Raf/MEK/ERK sequential signaling was up-regulated. Additionally, the transgenic human polycystin-2 partially rescues the lethality of Pkd2 knock-out mice and therefore demonstrates that the transgene generated a functional product. Functional strengthening or deregulated activation of PKD2 may be a direct cause of ADPKD. The present study provides evidence for an in vivo role of overexpressed PKD2 in cyst formation. This transgenic mouse model should provide new insights into the pathogenic mechanism of human ADPKD.
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Affiliation(s)
- Eun Young Park
- Department of Biological Science, Sookmyung Women's University, Seoul 140-742, Republic of Korea
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