Regulation of neurotrophin-3 gene transcription by Sp3 and Sp4 in neurons

• Published in: Journal of neurochemistry Vol. 100; no. 2; pp. 520 - 531
• Main Authors: Ishimaru, Naoki, Tabuchi, Akiko, Hara, Daichi, Hayashi, Hiroyuki, Sugimoto, Takayuki, Yasuhara, Masahiro, Shiota, Jun, Tsuda, Masaaki
• Format: Journal Article
• Language: English
• Published: Oxford, UK Oxford, UK : Blackwell Publishing Ltd 01.01.2007; Blackwell Publishing Ltd; Blackwell
• Subjects: Animals; Biological and medical sciences; Blotting, Western - methods; Cerebral Cortex - cytology; chromatin immunoprecipitation assay; cortical neurons; Deoxyribonucleic acid; DNA; Embryo, Mammalian; Fundamental and applied biological sciences. Psychology; Gene expression; Gene Expression Regulation - physiology; Genetics; Immunohistochemistry - methods; Molecular and cellular biology; Molecular genetics; Neurons; Neurons - drug effects; Neurons - metabolism; Neurotrophin 3 - genetics; Neurotrophin 3 - metabolism; neurotrophin‐3; Promoter Regions, Genetic; Rats; Reverse Transcriptase Polymerase Chain Reaction - methods; RNA interference; RNA Interference - physiology; RNA, Messenger - metabolism; Sp3 Transcription Factor - metabolism; Sp4 Transcription Factor - metabolism; specificity protein 1 family transcription factor; Transcription, Genetic - drug effects; Transcription, Genetic - physiology; Transcription. Transcription factor. Splicing. Rna processing; Neurotrophin; RNA interference; Transcription; chromatin immunoprecipitation assay; Transcription promoter; Central nervous system; Interference; specificity protein 1 family transcription factor; Protein; Encephalon; cortical neurons; Specificity; Neuron; Gene; Plasticity; Development; Transcription factor; neurotrophin-3
• ISSN: 0022-3042; 1471-4159
• DOI: 10.1111/j.1471-4159.2006.04216.x

Neurotrophin-3 (NT-3), a neurotrophin member, plays crucial roles in neuronal development, function and plasticity. Previous studies have demonstrated that NT-3 gene transcription is driven by alternative promoters A and B, located upstream of exons 1A (EIA) and 1B (EIB), respectively. However, the transcription factors and DNA elements that drive NT-3 gene transcription remain to be identified. Here, we analysed the promoter region of the NT-3 gene and found that an NT-3 transcript containing EIB is predominantly expressed in cortical neurons which preferentially utilize promoter B, and two tandemly repeated GC-boxes, located between -100 and -60 base pairs within promoter B, are required for the transcription. Electrophoretic mobility shift and chromatin immunoprecipitation assays revealed that both specificity protein (Sp)3 and Sp4 were able to bind to the Sp1 binding sequences within the GC boxes. Expression of dominant-negative Sp3 and Sp4 small interfering RNA in cortical neurons reduced the activity of the NT-3 gene promoter. Over-expression of Sp1 family members, especially Sp4, resulted in an increase of the NT-3 gene promoter. These findings indicate that the NT-3 gene is a target gene for Sp4 that is abundantly expressed in the brain.