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Immunodetection and localization of protein(s) related to retinal S‐antigen (arrestin) in kidney
Author(s) -
Mirshahi Massoud,
Razaghi Ahmad,
Vandewalle Alain,
Cluzeaud Françoise,
Tarraf Mohammed,
Faure JeanPierre
Publication year - 1992
Publication title -
biology of the cell
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.543
H-Index - 85
eISSN - 1768-322X
pISSN - 0248-4900
DOI - 10.1016/0248-4900(92)90210-r
Subject(s) - biology , retinal , arrestin , antigen , kidney , microbiology and biotechnology , immunology , biochemistry , genetics , signal transduction , g protein coupled receptor
Summary— S‐antigen (arrestin) is a cytosolic protein which regulates phototransduction in retinal rods. A protein immunologically related to S‐antigen was identified in fractions from soluble extract of bovine kidney enriched by gel filtration or by immunoaffinity chromatography using a polyclonal antibody to retinal S‐antigen. On immunoblots, this protein was recognized by a panel of monoclonal antibodies (mAbs S2D2, S1A3 and S9E2) directed against different S‐antigen epitopes and displayed the same apparent molecular mass (48 kDa) as retinal S‐antigen. All three mAbs revealed a specific immunoreactivity by indirect immunocytochemical technique on rat kidney sections. The three mAbs recognized some but not all glomerular cells, identified as epithelial cells by immunoelectron microscopy using the mAb S9E2. Both mAbs S2D2 and S1A3 gave a diffuse cytoplasmic staining in all tubule cells. Proximal tubule cells exhibited a weak immunoreactivity, whereas distal and collecting tubule cells were strongly labeled. In contrast, the mAb S9E2 immunoreaction was restricted to a cell subpopulation from distal and collecting tubules corresponding to intercalated cells identified by immunoelectron microscopy. With the mAb S9E2, the labeling of proximal tubule cells was localized in the apical region of the cytoplasm. These results suggest that two or more 48‐kDa proteins immunologically cross‐reactive with retinal S‐antigen are present in kidney. The observed pattern of distribution is in keeping with the hypothesis that such proteins could play a role in the regulation of G‐protein‐related receptors present in renal glomerules and tubule epithelial cells.