article published Gesa Rickheit author Lena Wartosch author Sven Schaffer author Sandra Stobrawa author Gaia Novarino author 3E57A680-F248-11E8-B48F-1D18A9856A870000-0002-7673-7178 Stefanie Weinert author Thomas Jentsch author Inactivation of the mainly endosomal 2Cl-/H+- exchanger ClC-5 severely impairs endocytosis in renal proximal tubules and underlies the human kidney stone disorder Dent's disease. In heterologous expression systems, interaction of the E3 ubiquitin ligasesWWP2and Nedd4-2 with a &quot;PY-motif&quot; in the cytoplasmic C terminus of ClC-5 stimulates its internalization from the plasma membrane and may influence receptor-mediated endocytosis. We asked whether this interaction is relevant in vivo and generated mice in which the PY-motif was destroyed by a point mutation. Unlike ClC-5 knock-out mice, these knock-in mice displayed neither low molecular weight proteinuria nor hyperphosphaturia, and both receptor-mediated and fluid-phase endocytosis were normal. The abundances and localizations of the endocytic receptor megalin and of the Na+-coupled phosphate transporter NaPi-2a (Npt2) were not changed, either. To explore whether the discrepancy in results from heterologous expression studies might be due to heteromerization of ClC-5 with ClC-3 or ClC-4 in vivo, we studied knock-in mice additionally deleted for those related transporters. Disruption of neither ClC-3 nor ClC-4 led to proteinuria or impaired proximal tubular endocytosis by itself, nor in combination with the PY-mutant of ClC-5. Endocytosis of cells lacking ClC-5 was not impaired further when ClC-3 or ClC-4 was additionally deleted. We conclude that ClC-5 is unique among CLC proteins in being crucial for proximal tubular endocytosis and that PY-motif-dependent ubiquitylation of ClC-5 is dispensable for this role. American Society for Biochemistry and Molecular Biology2010 10.1074/jbc.M110.115600 2852317595 - 17603 yes G. Rickheit <i>et al.</i>, “Role of ClC-5 in renal endocytosis is unique among ClC exchangers and does not require PY-motif-dependent ubiquitylation,” <i>Journal of Biological Chemistry</i>, vol. 285, no. 23. American Society for Biochemistry and Molecular Biology, pp. 17595–17603, 2010. Rickheit, G., Wartosch, L., Schaffer, S., Stobrawa, S., Novarino, G., Weinert, S., &#38; Jentsch, T. (2010). Role of ClC-5 in renal endocytosis is unique among ClC exchangers and does not require PY-motif-dependent ubiquitylation. <i>Journal of Biological Chemistry</i>. American Society for Biochemistry and Molecular Biology. <a href="https://doi.org/10.1074/jbc.M110.115600">https://doi.org/10.1074/jbc.M110.115600</a> Rickheit, Gesa, Lena Wartosch, Sven Schaffer, Sandra Stobrawa, Gaia Novarino, Stefanie Weinert, and Thomas Jentsch. “Role of ClC-5 in Renal Endocytosis Is Unique among ClC Exchangers and Does Not Require PY-Motif-Dependent Ubiquitylation.” <i>Journal of Biological Chemistry</i>. American Society for Biochemistry and Molecular Biology, 2010. <a href="https://doi.org/10.1074/jbc.M110.115600">https://doi.org/10.1074/jbc.M110.115600</a>. Rickheit G, Wartosch L, Schaffer S, et al. Role of ClC-5 in renal endocytosis is unique among ClC exchangers and does not require PY-motif-dependent ubiquitylation. <i>Journal of Biological Chemistry</i>. 2010;285(23):17595-17603. doi:<a href="https://doi.org/10.1074/jbc.M110.115600">10.1074/jbc.M110.115600</a> Rickheit G, Wartosch L, Schaffer S, Stobrawa S, Novarino G, Weinert S, Jentsch T. 2010. Role of ClC-5 in renal endocytosis is unique among ClC exchangers and does not require PY-motif-dependent ubiquitylation. Journal of Biological Chemistry. 285(23), 17595–17603. G. Rickheit, L. Wartosch, S. Schaffer, S. Stobrawa, G. Novarino, S. Weinert, T. Jentsch, Journal of Biological Chemistry 285 (2010) 17595–17603. Rickheit, Gesa, et al. “Role of ClC-5 in Renal Endocytosis Is Unique among ClC Exchangers and Does Not Require PY-Motif-Dependent Ubiquitylation.” <i>Journal of Biological Chemistry</i>, vol. 285, no. 23, American Society for Biochemistry and Molecular Biology, 2010, pp. 17595–603, doi:<a href="https://doi.org/10.1074/jbc.M110.115600">10.1074/jbc.M110.115600</a>. 23112018-12-11T11:56:55Z2021-01-12T06:56:42Z