Monoclonal antibody P-31 recognizes a novel intermediate filament-associated protein (p250) in rat podocytes.
The visceral glomerular epithelial cells (GECs) or podocytes of the renal glomerulus constitute a highly specialized epithelium. To study the nature of podocytes, we established mouse monoclonal antibodies against GEC. Clone P-31 reacted exclusively with the cytoplasm of GEC by immunofluorescence. Immunoblot analysis with P-31 showed that a single band of 250 kDa was detectable in a glomerular lysate. The 250-kDa polypeptide (p250) was recovered from Triton X-100-insoluble fractions of isolated glomeruli, suggesting that this molecule is associated with the cytoskeleton. Immunogold staining with P-31 demonstrated that the gold particles were located at the intersections of vimentin-type intermediate filaments of podocytes. In developing kidney, this protein first appeared in immature GECs during the S-shaped body stage. In puromycin aminonucleoside nephrosis, p250 was dramatically increased in glomeruli where enhanced desmin expression was observed in GECs. These results indicate that p250 is a novel intermediate filament-associated protein and plays a role in the organization of the intermediate filament network in both normal and diseased conditions.
Kurihara
H
H
Shionogi Research Laboratories, Osaka, Japan.
Sunagawa
N
N
Kobayashi
T
T
Kimura
K
K
Takasu
N
N
Shike
T
T
D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology*; D000918:Antibody Specificity; D000941:Antigens / Q000276:immunology; D004847:Epithelial Cells / Q000276:immunology*; D005260:Female; D007150:Immunohistochemistry; D007382:Intermediate Filaments / Q000276:immunology*; D007678:Kidney Glomerulus / Q000276:immunology*; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D008856:Microscopy, Fluorescence; D011506:Proteins / Q000276:immunology*; D051381:Rats; D017207:Rats, Sprague-Dawley
D000911:Antibodies, Monoclonal; D000941:Antigens; D011506:Proteins