A developmentally regulated DNA-binding protein from mouse brain stimulates myelin basic protein gene expression

Area of Science:

• Neuroscience
• Molecular Biology
• Genetics

Background:

• Myelin basic protein (MBP) gene transcription is tightly regulated during central nervous system myelin formation.
• The 5'-flanking region of the MBP gene contains regulatory elements controlling cell-type-specific transcription.
• The MB1 element (-14 to -50) acts as a cell-type-specific enhancer for MBP transcription.

Purpose of the Study:

• To identify DNA-binding proteins interacting with the MB1 regulatory element of the MBP gene.
• To characterize the role of these proteins in regulating MBP gene transcription.

Main Methods:

• Band shift assays and UV cross-linking were employed using mouse brain nuclear extracts.
• Fractionation of nuclear extracts to isolate specific DNA-binding proteins.
• Assays to determine the effect of purified proteins on MBP promoter activity in HeLa cell extracts.

Main Results:

• A 38- to 41-kDa nuclear protein specifically binds to the MB1 DNA sequence in mouse brain extracts.
• This protein's activity is highest in brain tissue during peak myelination.
• Fractions containing the MB1-binding protein stimulated MBP promoter transcription in HeLa cell extracts.

Conclusions:

• A specific MB1-binding protein has been identified in mouse brain nuclear extracts.
• The activity of this protein is tissue-specific and developmentally regulated, mirroring MBP transcription patterns.
• This protein is a potential biologically relevant transcription factor for the MBP gene in vivo.