Developmental expression and intracellular location of P 400 protein characteristic of Purkinje cells in the mouse cerebellum

Abstract

The developmental expression and intracellular localization of a cerebellum-characteristic 250-kDa glycoprotein, P 400 protein, were studied by immunohistochemical and immunoblot methods using a monoclonal antibody against P 400 protein. In the cerebellum of normal mouse, the expression of P 400 protein increased from Postnatal Day 3 to Day 21. This enhancement of P 400 protein expression occurred only in the Purkinje cells and proceeded with the growth of their dendritic arborization. Electron microscopic analysis indicated that P 400 protein is present at the plasma membrane, the endoplasmic reticulum, and the postsynaptic densities of Purkinje cells. Immunohistochemistry of the cerebella of neurological mutant mice indicated that the Purkinje cells of reeler, weaver, and pcd mutant mice retain the ability to produce a large amount of P 400 protein. However, the Purkinje cells of staggerer mutant mouse proved to be incapable of enhanced P 400 protein expression. These results indicate that P 400 protein is a Purkinje cell-characteristic plasma membrane-associated glycoprotein, which is also present at the postsynaptic density and endoplasmic reticulum and that the expression of P 400 protein in Purkinje cells is closely associated with the growth of their dendritic arborization.