Regional expression and subcellular localization of the tyrosine-specific phosphatase SH-PTP2 in the adult human nervous system.

The protein tyrosine phosphatase SH-PTP2 has been implicated in a variety of cell signaling cascades, including those mediating neuronal survival. We therefore investigated the expression of SH-PTP2 in the adult human nervous system using Western blotting, immunohistochemistry and immunoelectron microscopy. SH-PTP2 immunoreactivity was noted only in neurons, but was not restricted to a specific neuronal type or location. Immunohistochemistry showed perikaryal staining, whereas Western blotting and ultrastructural analysis suggested that SH-PTP2 is present in axons as well. While immunohistochemistry showed a Nissl-like pattern in large motor neurons, immunoelectron microscopy demonstrated a diffuse pattern of cytoplasmic staining, without apparent preferential localization. The presence of the SH2 domain-containing tyrosine-specific phosphatase SH-PTP2 in diverse neurons in the adult nervous system suggests that SH-PTP2 may play a role in a broad spectrum of neuronal responses.