First Author | Pogulis RJ | Year | 1993 |
Journal | J Biol Chem | Volume | 268 |
Issue | 4 | Pages | 2493-9 |
PubMed ID | 8428926 | Mgi Jnum | J:3897 |
Mgi Id | MGI:52402 | Doi | 10.1016/s0021-9258(18)53803-5 |
Citation | Pogulis RJ, et al. (1993) Contribution of specific cis-acting elements to activity of the mouse pro-alpha 2(I) collagen enhancer. J Biol Chem 268(4):2493-9 |
abstractText | Intronic transcriptional regulatory regions are found in several collagen genes. We demonstrate here the importance of two distinct cis-acting elements for the activity of a transcriptional enhancer located in the first intron of the mouse pro-alpha 2(I) collagen gene. Enhancer subfragments were tested for their ability to stimulate a linked promoter following transient transfection into NIH/3T3 fibroblasts. A 92-base pair subfragment retained significant enhancer activity. DNase I footprinting identified a binding site for a nuclear factor (designated CIBF-I) within this subfragment. Electrophoretic mobility-shift experiments demonstrated that an oligonucleotide containing 18 base pairs from the protected region was sufficient for specific binding of CIBF-I and suggested that CIBF-I may be related to a protein(s) that binds to the rat c-mos enhancer. A second cis-acting element, identified by electrophoretic mobility-shift and methylation interference experiments, bound affinity-purified Sp1 and an Sp1-like protein present in crude nuclear extracts. Small deletion mutations in either the CIBF-I or Sp1 site abolished factor binding in vitro and reduced enhancer activity in vivo. Our results represent the first identification of specific cis-acting elements required for full activity of the pro-alpha 2(I) collagen enhancer. |