Developmental analysis of factors binding to the mouse 68-kDa neurofilament promoter.

Whole tissue extracts prepared from mouse brain regions at various postnatal ages were characterized for binding of factors to the DNase I hypersensitive site (HSSI) which is located closest to the transcription start site of the 68-kDa mouse neurofilament gene (NF-L). Gel mobility shift assays detected changes in factor binding during postnatal development of the neocortex. Competition experiments suggested that one of the complexes resulted from factor binding to a 9 bp sequence found in both the light and medium neurofilament promoter regions (NF-L/M). Gel mobility shifts performed with an oligonucleotide probe containing the NF-L/M sequence detected two brain-specific DNA-protein complexes, and a third complex in both brain and liver. During cerebellar and neocortical development, one of the NF-L/M complexes was most intense at postnatal day 10 when transcription of the NF-L gene is upregulated.