Kerim Mutig, Thomas Kahl, Turgay Saritas, Michael Godes, Pontus Persson, James Bates, Hajamohideen Raffi, Luca Rampoldi, Shinichi Uchida, Carsten Hille, Carsten Dosche, Satish Kumar, Maria Castaneda-Bueno, Gerardo Gamba, Sebastian Bachmann
- Active transport of NaCl across thick ascending limb (TAL) epithelium is accomplished by Na+, K+,2Cl(-) cotransporter (NKCC2). The activity of NKCC2 is determined by vasopressin (AVP) or intracellular chloride concentration and includes its amino-terminal phosphorylation. Co-expressed Tamm-Horsfall protein (THP) has been proposed to interact with NKCC2. We hypothesized that THP modulates NKCC2 activity in TAL. THP-deficient mice (THP-/-) showed an increased abundance of intracellular NKCC2 located in subapical vesicles (+47% compared with wild type (WT) mice), whereas base-line phosphorylation of NKCC2 was significantly decreased (-49% compared with WT mice), suggesting reduced activity of the transporter in the absence of THP. Cultured TAL cells with low endogenous THP levels and low base-line phosphorylation of NKCC2 displayed sharp increases in NKCC2 phosphorylation (+38%) along with a significant change of intracellular chloride concentration upon transfection with THP. In NKCC2-expressing frog oocytes, co-injection with THP cRNAActive transport of NaCl across thick ascending limb (TAL) epithelium is accomplished by Na+, K+,2Cl(-) cotransporter (NKCC2). The activity of NKCC2 is determined by vasopressin (AVP) or intracellular chloride concentration and includes its amino-terminal phosphorylation. Co-expressed Tamm-Horsfall protein (THP) has been proposed to interact with NKCC2. We hypothesized that THP modulates NKCC2 activity in TAL. THP-deficient mice (THP-/-) showed an increased abundance of intracellular NKCC2 located in subapical vesicles (+47% compared with wild type (WT) mice), whereas base-line phosphorylation of NKCC2 was significantly decreased (-49% compared with WT mice), suggesting reduced activity of the transporter in the absence of THP. Cultured TAL cells with low endogenous THP levels and low base-line phosphorylation of NKCC2 displayed sharp increases in NKCC2 phosphorylation (+38%) along with a significant change of intracellular chloride concentration upon transfection with THP. In NKCC2-expressing frog oocytes, co-injection with THP cRNA significantly enhanced the activation of NKCC2 under low chloride hypotonic stress (+112% versus +235%). Short term (30 min) stimulation of the vasopressin V2 receptor pathway by V2 receptor agonist (deamino-cis-D-Arg vasopressin) resulted in enhanced NKCC2 phosphorylation in WT mice and cultured TAL cells transfected with THP, whereas in the absence of THP, NKCC2 phosphorylation upon deamino-cis-D-Arg vasopressin was blunted in both systems. Attenuated effects of furosemide along with functional and structural adaptation of the distal convoluted tubule in THP-/- mice supported the notion that NaCl reabsorption was impaired in TAL lacking THP. In summary, these results are compatible with a permissive role for THP in the modulation of NKCC2-dependent TAL salt reabsorptive function.…
MetadatenVerfasserangaben: | Kerim Mutig, Thomas Kahl, Turgay Saritas, Michael Godes, Pontus Persson, James Bates, Hajamohideen Raffi, Luca Rampoldi, Shinichi Uchida, Carsten HilleORCiDGND, Carsten DoscheGND, Satish Kumar, Maria Castaneda-Bueno, Gerardo Gamba, Sebastian Bachmann |
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DOI: | https://doi.org/10.1074/jbc.M111.222968 |
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ISSN: | 0021-9258 |
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Titel des übergeordneten Werks (Englisch): | The journal of biological chemistry |
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Verlag: | American Society for Biochemistry and Molecular Biology |
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Verlagsort: | Bethesda |
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Publikationstyp: | Wissenschaftlicher Artikel |
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Sprache: | Englisch |
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Jahr der Erstveröffentlichung: | 2011 |
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Erscheinungsjahr: | 2011 |
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Datum der Freischaltung: | 26.03.2017 |
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Band: | 286 |
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Ausgabe: | 34 |
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Seitenanzahl: | 11 |
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Erste Seite: | 30200 |
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Letzte Seite: | 30210 |
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Fördernde Institution: | Deutsche Forschungsgemeinschaft [FOR 667]; Leducq Foundation; Consejo
Nacional de Ciencia y Tecnologia [59992] |
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Organisationseinheiten: | Mathematisch-Naturwissenschaftliche Fakultät / Institut für Biochemie und Biologie |
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Peer Review: | Referiert |
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