IMMUNOHISTOCHEMICAL LOCALIZATION OF RECOVERIN-LIKE CA2+-BINDING PROTEIN (P23K) IN MOUSE-BRAIN

An immunohistochemical study was carried out to determine the localization of recoverin-like Ca2+-binding protein (P23k) in mouse brain. P23k was found in pyramidal neurons in the cerebral cortex and hippocampus, granule cells in the cerebellum, periglomerular cells in the olfactory bulb, and neuronal cells in the paraventricular nucleus of the hypothalamus and the posterior mamillary nucleus. In most cell types, P23k was localized mainly on the plasma membrane, and partly in the cytosol. Since P23k has a Ca2+-dependent membrane-binding property, the difference in the subcellular localization of P23k seems to be caused by the variety of intracellular Ca2+-levels in the positive cells. The wide range of positive cell types implies that P23k may have a wide range of physiological functions.