Expression analyses of PLEKHG2, a Rho family-specific guanine nucleotide exchange factor, during mouse brain development.

Abnormalities of PLEKHG2 gene, encoding a Rho family-specific guanine nucleotide exchange factor, are involved in microcephaly with intellectual disability. However, not only the role of PLEKHG2 in the developmental process but also its expression profile is unknown. In this study, we prepared a specific antibody against PLEKHG2 and carried out expression analyses with mouse tissues. In western blotting, PLEKHG2 exhibited a tissue-dependent expression profile in adult mouse and was expressed in a developmental stage-dependent manner in brain. Then, in immunohistochemical analyses, while PLEKHG2 was observed in the cortical plate and ventricular zone surface of the cerebral cortex at embryonic day 14, it came to be distributed throughout the cerebral cortex in layer II/III and V during corticogenesis. PLEKHG2 was also detected mainly in the nucleus of neurons in the hippocampal CA regions and dentate gyrus at P7. Notably, the nuclear accumulation disappeared at P30 and PLEKHG2 came to be located at the axons and/or dendrites at this time point. Moreover, in vitro immunofluorescence revealed that PLEKHG2 was at least partially localized at both excitatory and inhibitory synapses in primary cultured hippocampal neurons. These results suggest roles of PLEKHG2 in the development of the central nervous tissue and synaptic function.