CORE PROMOTER OF THE MOUSE MYELIN BASIC-PROTEIN GENE GOVERNS BRAIN-SPECIFIC TRANSCRIPTION INVITRO

The core promoter of the mouse myelin basic protein (MBP) gene from -36 to +12 was preferentially transcribed in brain nuclear extracts. Both the TATA at -34 and downstream elements to +12 were required for efficient, accurate and brain-specific transcription. From brain and liver nuclear extracts, we have partially purified the general transcription factor TFIID. The partially purified fractions contained TATA element binding factors of the MBP promoter as well as adenovirus major late promoter (MLP). The tissue-derived TFIID was functionally exchangeable for the HeLa TFIID, and directed transcription from the MLP. Surprisingly, the brain TFIID activated transcription from the MBP core promoter while the liver TFIID did to a much lesser extent. Exchange of the TATA-containing short DNA stretch to the MBP core promoter for a corresponding region of the mouse albumin promoter or MLP abolished the brain specificity. We found that several tissue-specific promoters other than MBP, such as mouse neurofilament and human α-1-antitrypsin promoters were also transcribed much more efficiently by the brain and liver TFIID, respectively. We suggest that different tissues contain functionally non-equivalent TFIID or TFIID-like activities.