TY - JOUR
T1 - Involvement of lipid rafts in nephrin phosphorylation and organization of the glomerular slit diaphragm
AU - Simons, Matias
AU - Schwarz, Karin
AU - Kriz, Wilhelm
AU - Miettinen, Aaro
AU - Reiser, Jochen
AU - Mundel, Peter
AU - Holthöfer, Harry
N1 - Funding Information:
Supported by the European Union grant “Quality of Life and Management of Living Resources,” a grant from the University of Helsinki, and a grant from the Deutsche Forschungsgemeinschaft ( SFB352 ). M. S. was a recipient of an EMBO short-term fellowship.
PY - 2001
Y1 - 2001
N2 - NPHS1 has recently been identified as the gene whose mutations cause congenital nephrotic syndrome of the Finnish type. The respective gene product nephrin is a transmembrane protein expressed in glomerular podocytes and primarily localized to the glomerular slit diaphragm. This interpodocyte junction functions in the glomerular filtration by restricting the passage of plasma proteins into the urinary space in a size-selective manner. The functional role of nephrin in this filtration process is so far not very well understood. In this study, we show that nephrin associates in an oligomerized form with signaling microdomains, also known as lipid rafts, and that these localize to the slit diaphragm. We also show that the nephrin-containing rafts can be immunoisolated with the 27A antibody recognizing a podocyte-specific 9-O-acetylated GD3 ganglioside. In a previous study it has been shown that the in vivo injection of this antibody leads to morphological changes of the filtration slits resembling foot process effacement. Here, we report that, in this model of foot process effacement, nephrin dislocates to the apical pole of the narrowed filtration slits and also that it is tyrosine phosphorylated. We suggest that lipid rafts are important in the spatial organization of the glomerular slit diaphragm under physiological and pathological conditions.
AB - NPHS1 has recently been identified as the gene whose mutations cause congenital nephrotic syndrome of the Finnish type. The respective gene product nephrin is a transmembrane protein expressed in glomerular podocytes and primarily localized to the glomerular slit diaphragm. This interpodocyte junction functions in the glomerular filtration by restricting the passage of plasma proteins into the urinary space in a size-selective manner. The functional role of nephrin in this filtration process is so far not very well understood. In this study, we show that nephrin associates in an oligomerized form with signaling microdomains, also known as lipid rafts, and that these localize to the slit diaphragm. We also show that the nephrin-containing rafts can be immunoisolated with the 27A antibody recognizing a podocyte-specific 9-O-acetylated GD3 ganglioside. In a previous study it has been shown that the in vivo injection of this antibody leads to morphological changes of the filtration slits resembling foot process effacement. Here, we report that, in this model of foot process effacement, nephrin dislocates to the apical pole of the narrowed filtration slits and also that it is tyrosine phosphorylated. We suggest that lipid rafts are important in the spatial organization of the glomerular slit diaphragm under physiological and pathological conditions.
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U2 - 10.1016/S0002-9440(10)61782-8
DO - 10.1016/S0002-9440(10)61782-8
M3 - Article
C2 - 11549599
AN - SCOPUS:0034858027
SN - 0002-9440
VL - 159
SP - 1069
EP - 1077
JO - American Journal of Pathology
JF - American Journal of Pathology
IS - 3
ER -