In vitro transcription of immunoglobulin genes in a B-cell extract: effects of enhancer and promoter sequences.

Transfection experiments have led to the identification of three DNA sequences that are responsible for the tissue-specific expression of immunoglobulin genes. As a first step toward characterizing these regulatory phenomena at the biochemical level, we report the development of an in vitro transcription system from cells of the B lymphoid lineage. In these extracts, transcription of the MOPC41 kappa promoter is correctly initiated and dependent on the presence of an upstream sequence element located between -44 and -79 base pairs from the cap site. Second, although standard in vitro transcriptions are not affected by the presence or absence of enhancer sequences, we observed that the addition of polyethylene glycol led to a B-cell extract-specific suppression of transcription from a template that carries an immunoglobulin enhancer.