CHARACTERIZATION OF A NOVEL ISOFORM OF NOS1AP: NOS1APc

Abstract

The current study characterizes a novel isoform of the Nitric Oxide Synthase 1 Adaptor Protein (NOS1AP), herein NOS1APc. NOS1APc was identified in a proteomic screen for Scribble interacting proteins. Northern blot analysis revealed a 7kb transcript that was present in a number of different tissues and cell lines. Highest levels were detected in the cerebellum. In situ hybridization studies revealed NOS1APc mRNA throughout the cortex and hippocampus. In addition, cerebellar Purkinje cells and different brainstem nuclei also contained NOS1APc mRNA. Antibodies directed against NOS1APc revealed a 100 kDa protein, while immunohistochemical staining revealed high levels of this protein within the molecular layer of the cerebellum. Finally, immunocytochemical studies using isolated primary astrocytes revealed a subset of BrdU positive nuclei that co-expressed NOS1APc, suggesting that this protein may function in some capacity in cell-cycle progression.