LOCALIZATION OF SEVERAL G-PROTEIN SUBUNITS IN HUMAN KIDNEY

Localization of guanine nucleotide binding protein (G-protein) alpha chains in human kidney was examined using immunoblotting and immunocytochemical techniques. Immunoblot studies revealed G alpha s, G alpha i(1/2) and G alpha i(3) proteins in membrane fractions of glomeruli, cortical tubules and medullary tubules. Immunocytochemical studies confirmed the presence of these G-proteins in several parts of human nephron. The results demonstrate the presence of a large amount of G-protein alpha subunits in human nephron segments. We speculate that G-protein in human kidney may play an important physiological role well-defined in other mammmalia.