Lysine 246 of the vitamin D receptor is crucial for ligand-dependent interaction with coactivators and transcriptional activity
Lysine 246 of the vitamin D receptor is crucial for ligand-dependent interaction with coactivators and transcriptional activity
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DOI：
10.1074/jbc.274.19.13503
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发表时间：
1999-05-07
影响因子：
4.8
通讯作者：
Aranda, A
中科院分区：
文献类型：
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作者：
Jiménez-Lara, AM;Aranda, A
在预测的配体结合结构域的螺旋3中产生突变体R246 A，以及在螺旋12中产生突变体L417 S和E420 Q，其包含核心配体依赖性转录激活结构域（AF-2），以检测维生素D受体（VDR）的AF-2活性。此外，VDR介导视黄酸受体β 2启动子对视黄酸的反应的配体依赖性抑制，螺旋3和螺旋12突变体不能介导反式抑制。此外，VDR突变体，而不是天然受体，增强佛波酯诱导的激活蛋白-1-含有胶原酶启动子。螺旋3和螺旋12突变显著降低了VDR与类固醇受体共激活因子-1，ACTR和CREB结合蛋白相互作用的能力。因此，类固醇受体辅激活因子-1的过度表达增加维生素D依赖性VDR的反式激活，但不是由K246 A突变体。这些结果表明，赖氨酸246参与，与螺旋12中的残基一起，在募集的辅激活剂和AF-2的活性都涉及配体依赖性的反式激活和VDR的反式阻遏。
Mutant R246A in the predicted helix 3 of the ligand-binding domain, as well as mutants L417S and E420Q in helix 12, which contains the core ligand-dependent transcriptional activation domain (AF-2), were generated to examine AF-2 activity of the vitamin D receptor (VDR), These mutations abolished vitamin D-dependent transactivation. In addition, VDR mediates a ligand-dependent repression of the response of the retinoic acid receptor beta 2 promoter to retinoic acid, and the helix 3 and helix 12 mutants were unable to mediate transrepression. Furthermore, the VDR mutants, but not the native receptor, enhanced phorbol ester induction of the activator protein-1-containing collagenase promoter. The helix 3 and helix 12 mutations strikingly reduced the ability of VDR to interact with the coactivators steroid receptor coactivator-1, ACTR, and the CREB-binding protein. As a consequence, overexpression of steroid receptor coactivator-1 increased vitamin D-dependent transactivation by VDR but not by the K246A mutant. These results indicate that the lysine 246 participates, together with residues in helix 12, in the recruitment of coactivators and that AF-2 activity is involved both in ligand dependent transactivation and in transrepression by VDR.