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Salin-Cantegrel A, Shekarabi M, Rasheed S, Charron FM, Laganière J, Gaudet R, Dion PA, Lapointe JY, Rouleau GA. Potassium-chloride cotransporter 3 interacts with Vav2 to synchronize the cell volume decrease response with cell protrusion dynamics. PLoS One 2013; 8:e65294. [PMID: 23724134 PMCID: PMC3665532 DOI: 10.1371/journal.pone.0065294] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2011] [Accepted: 04/29/2013] [Indexed: 12/01/2022] Open
Abstract
Loss-of-function of the potassium-chloride cotransporter 3 (KCC3) causes hereditary motor and sensory neuropathy with agenesis of the corpus callosum (HMSN/ACC), a severe neurodegenerative disease associated with defective midline crossing of commissural axons in the brain. Conversely, KCC3 over-expression in breast, ovarian and cervical cancer is associated with enhanced tumor cell malignancy and invasiveness. We identified a highly conserved proline-rich sequence within the C-terminus of the cotransporter which when mutated leads to loss of the KCC3-dependent regulatory volume decrease (RVD) response in Xenopus Laevis oocytes. Using SH3 domain arrays, we found that this poly-proline motif is a binding site for SH3-domain containing proteins in vitro. This approach identified the guanine nucleotide exchange factor (GEF) Vav2 as a candidate partner for KCC3. KCC3/Vav2 physical interaction was confirmed using GST-pull down assays and immuno-based experiments. In cultured cervical cancer cells, KCC3 co-localized with the active form of Vav2 in swelling-induced actin-rich protruding sites and within lamellipodia of spreading and migrating cells. These data provide evidence of a molecular and functional link between the potassium-chloride co-transporters and the Rho GTPase-dependent actin remodeling machinery in RVD, cell spreading and cell protrusion dynamics, thus providing new insights into KCC3's involvement in cancer cell malignancy and in corpus callosum agenesis in HMSN/ACC.
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Affiliation(s)
- Adèle Salin-Cantegrel
- Centre of Excellence in Neuroscience of University of Montreal, Montréal, Québec, Canada
- Centre Hospitalier de l′Université de Montréal Research Centre, Montréal, Québec, Canada
| | - Masoud Shekarabi
- Centre of Excellence in Neuroscience of University of Montreal, Montréal, Québec, Canada
- Centre Hospitalier de l′Université de Montréal Research Centre, Montréal, Québec, Canada
| | - Sarah Rasheed
- Centre of Excellence in Neuroscience of University of Montreal, Montréal, Québec, Canada
- Centre Hospitalier de l′Université de Montréal Research Centre, Montréal, Québec, Canada
| | | | - Janet Laganière
- Centre of Excellence in Neuroscience of University of Montreal, Montréal, Québec, Canada
- Centre Hospitalier de l′Université de Montréal Research Centre, Montréal, Québec, Canada
| | - Rebecca Gaudet
- Centre of Excellence in Neuroscience of University of Montreal, Montréal, Québec, Canada
- Centre Hospitalier de l′Université de Montréal Research Centre, Montréal, Québec, Canada
| | - Patrick A. Dion
- Centre of Excellence in Neuroscience of University of Montreal, Montréal, Québec, Canada
- Centre Hospitalier de l′Université de Montréal Research Centre, Montréal, Québec, Canada
- Department of Pathology and Cell Biology, Université de Montréal, Montréal, Québec, Canada
| | | | - Guy A. Rouleau
- Centre of Excellence in Neuroscience of University of Montreal, Montréal, Québec, Canada
- Centre Hospitalier de l′Université de Montréal Research Centre, Montréal, Québec, Canada
- Montreal Neurological Institute, McGill University, Montréal, Québec, Canada
- * E-mail:
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Functional analysis of a potassium-chloride co-transporter 3 (SLC12A6) promoter polymorphism leading to an additional DNA methylation site. Neuropsychopharmacology 2009; 34:458-67. [PMID: 18536702 DOI: 10.1038/npp.2008.77] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
The human potassium-chloride co-transporter 3 (KCC3, SLC12A6) is involved in cell proliferation and in electro-neutral movement of ions across the cell membrane. The gene (SLC12A6) is located on chromosome 15q14, a region that has previously shown linkage with bipolar disorder, schizophrenia, rolandic epilepsy, idiopathic generalized epilepsy, autism and attention deficit/hyperactivity disorder. Furthermore, recessively inherited mutations of SLC12A6 cause Andermann syndrome, characterized by agenesis of the corpus callosum, which is associated with peripheral neuropathy and psychoses. Recently, we have demonstrated the association of two G/A promoter polymorphisms of SLC12A6 with bipolar disorder in a case-control study, and familial segregation of the rare variants as well as a trend toward association with schizophrenia. To investigate functional consequences of these polymorphisms, lymphocyte DNA was extracted, bisulfite modified, and subsequently sequenced. To investigate SLC12A6 promoter activity, various promoter constructs were generated and analyzed by luciferase reporter gene assays. We provide evidence that the G- allele showed a significant reduction of reporter gene expression. In human lymphocytes, the allele harboring the rare upstream G nucleotide was found to be methylated at the adjacent C position, possibly accountable for tissue-specific reduction in gene expression in vivo. Here we demonstrate functionality of an SNP associated with psychiatric disease and our results may represent a functional link between genetic variation and an epigenetic modification.
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