Distribution and expression of protein kinase c interactive protein (PKCI/HINT1) in mouse central nervous system (CNS)

Protein kinase C interactive protein (PKCI; also known as histidine triad protein, HINT1) is a small intracellular protein widely expressed in tissues from both the peripheral and CNS. Although the structure of this protein is well characterized, the functional aspect and cellular distribution of the protein remain unknown, especially in CNS. To analyze the expression pattern of PKCI/HINT1 we used antibodies against either the whole recombinant protein or a peptide epitope of PKCI/HINT1. We find widespread of PKCI/HINT1 expression in the mouse CNS by Western blot and immunostaining. Our data indicates that PKCI/HINT1 is present broadly throughout the regions of CNS with relatively high abundance in olfactory system, cerebral cortex, hippocampus and part of thalamus, hypothalamus, midbrain, pons and medulla. On the cellular level, PKCI/HINT1 immunoreactivity is primarily located in neurons and neuronal processes. This study provides the anatomical evidence for the potential roles of PKCI/HINT1 in neuronal function.