Muñoz-Cánoves P, Vik D P, Tack B F
Department of Immunology, Scripps Clinic and Research Foundation, La Jolla, California 92037.
J Biol Chem. 1990 Nov 25;265(33):20065-8.
Retinoic acid receptors are members of the steroid/thyroid hormone receptor superfamily. Pursuant to the discovery that dexamethasone increases complement factor H expression, we examined the effects of retinoic acid on this gene. Both H mRNA and protein levels are increased by retinoic acid in L cells. Using the luciferase reporter gene system we have identified a region of the H promoter required for the retinoic acid response. This region contains an imperfect palindrome of the TGACC motif, present in thyroid hormone and estrogen-responsive elements. We demonstrate specific binding of the retinoic acid receptor beta to this sequence of the H gene by DNA-protein gel retardation assay. Therefore, these studies extend the sphere of influence of the retinoids to complement, an intrinsic component of the humoral immune system.
维甲酸受体是类固醇/甲状腺激素受体超家族的成员。鉴于地塞米松可增加补体因子H表达这一发现，我们研究了维甲酸对该基因的影响。在L细胞中，维甲酸可使H mRNA和蛋白质水平均升高。利用荧光素酶报告基因系统，我们确定了维甲酸反应所需的H启动子区域。该区域包含TGACC基序的不完全回文结构，存在于甲状腺激素和雌激素反应元件中。我们通过DNA-蛋白质凝胶阻滞试验证明了维甲酸受体β与H基因的这一序列存在特异性结合。因此，这些研究将类维生素A的影响范围扩展到补体，补体是体液免疫系统的一个固有成分。
