Soulez M, Tuil D, Kahn A, Phan-Dinh-Tuy F
ICGM, U129, INSERM, Paris, France.
Biochem Biophys Res Commun. 1993 Aug 31;195(1):400-8. doi: 10.1006/bbrc.1993.2057.
CArG boxes (CC(A/T)6GG sequences) are present in various promoters and are able to confer two different types of transcriptional responsiveness: serum inducibility and muscle-specific activation. Inserted upstream from the ubiquitous HSV thymidine kinase promoter, multimerized HCA1 boxes (human cardiac alpha-actin proximal CArG box) behave as strong muscle-specific activating elements. Transient expression assay was used to determine whether the muscle-specific transcriptional activation by the CArG boxes depends on the presence in the vicinity of other specific cis-acting DNA elements. Our results show that no specific association between different regulatory binding sites is required for the myogenic activity of a CArG box and that CArG elements are able to stimulate transcription in myogenic cells through either homophilic or heterophilic interactions of the CArG box binding factors.
CArG 框（CC(A/T)6GG 序列）存在于多种启动子中，能够赋予两种不同类型的转录反应性：血清诱导性和肌肉特异性激活。多聚化的 HCA1 框（人心脏α-肌动蛋白近端 CArG 框）插入到普遍存在的单纯疱疹病毒胸苷激酶启动子上游后，可作为强大的肌肉特异性激活元件。采用瞬时表达分析来确定 CArG 框的肌肉特异性转录激活是否依赖于其他特定顺式作用 DNA 元件的存在。我们的结果表明，CArG 框的成肌活性不需要不同调控结合位点之间的特异性关联，并且 CArG 元件能够通过 CArG 框结合因子的同源或异源相互作用刺激成肌细胞中的转录。
