Expression of Pituitary Tumor Transforming Gene-1 Proto-Oncogene is Upregulated in the Brain of Neuronal-Specific Neural Salient Serine/Arginine Rich Protein-1 Gene Knockout Mice

Background: NSSR1 (neural salient serine/arginine rich protein-1) is a neuron-specific expressed SR proteins which is involved in promoting neuronal differentiation. The purpose of this study is to start to explore the role of NSSR1 in mouse brain development through searching for the downstream genes that might be regulated by it. Methods and Materials: Neuron-specific NSSR1 gene knockout mice (NSSR1 cKO mice) were firstly constructed and then the differential expressed genes between brain tissues of NSSR1 cKO and its control mice were analyzed by microarray. Differential expression of several neural function-related genes was further validated by RT-qPCR and Western blot analysis. Results: The expression of pituitary tumor transforming gene-1 (PTTG1), a proto-oncogene, was significantly up-regulated in NSSR1 cKO mice brain. PTTG1 mRNA and protein were up-regulated mainly in cerebral cortex and hippocampal DG region of NSSR1 cKO mice, and the upregulated PTTG1 protein was located in the NeuN positive neurons. Coincidentally, overexpression of NSSR1 in N2a neural cells downregulated the PPTG1 expression in the in vitro analysis. Conclusion: We successfully constructed the neuron-specific NSSR1 gene knockout mice, and screened out the proto-oncogene PTTG1, whose expression can be downregulated by NSSR1 in neurons.