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Acta Physiologica 2006; Volume 186, Supplement 650
Joint Meeting of The German Society of Physiology and The Federation of European Physiological Societies 2006
3/26/2006-3/29/2006
Ludwig-Maximilians-University, Munich
REGULATED INTERNALIZATION OF THE RENAL NA+/PHOSPHATE COTRANSPORTER NAPI-IIA
Abstract number: ST5-4
Wagner1 CA, Capuano1 P, Bacic1,2 D, Gisler1 SM, Bielesz1 B, Kocher3 O, Weinman4 EJ, Kumar5 R, Kaissling2 B, Biber1 J, Murer1 H
1Institute of Physiology and Center for, Integrative Human Physiology, University of Zurich
2Institute of Anatomy, University of Zurich
3Depart. of Pathology Harvard Medical School
4Depart. of Medicine, Univ. of Maryland
5Mayo Clinic Rochester
Systemic phosphate homeostasis is regulated by dietary intake, distribution into different body compartments and renal loss of phosphate. Rapid internalization of the renal Na+/phosphate cotransporter NaPi-IIa from the brush border membrane is one means to increase renal phosphate excretion and is highly regulated, i.e. by parathyroid hormone (PTH). Initiation of normal internalization by PTH requires an apical signaling complex consisting of scaffold proteins like NHERF1 and PDZK1. NaPi-IIa is then directed to lysosomes for degradation sharing the route of receptor-mediated endoyctosis. Examples of factors down-regulating NaPi-IIa include also so-called phosphatonins (FGF-23, sFRP4, FGF7) that induce NaPi-IIa internalization and underlie several renal phosphate wasting disorders.
To cite this abstract, please use the following information:
Acta Physiologica 2006; Volume 186, Supplement 650 :ST5-4