Contribution of Promoter to Tissue-Specific Expression of the Mouse Immunoglobulin Kappa Gene

Abstract
The immunoglobulin kappa (κ) gene promoter was activated by a "neutral" enhancer derived from Harvey murine sarcoma virus (HaMuSV) in immunoglobulin-producing myeloma cells, regardless of the enhancer's orientation or position in the vector. In one fibroblast line (3T3) the immunoglobulin κ gene promoter was completely inactive when linked to the HaMuSV enhancer, whereas in mouse L cells, promoter activity was observed only with the HaMuSV enhancer in tandem with the immunoglobulin κ gene promoter. The differential behavior of the gene promoter, when activated by a neutral enhancer in these three murine cell lines, suggests that promoter sequences contribute to the tissue-specific expression of this gene.