Deed R W, Jasiok M, Norton J D
CRC Department of Gene Regulation, Paterson Institute for Cancer Research, Christie Hospital NHS Trust, UK.
FEBS Lett. 1996 Sep 9;393(1):113-6. doi: 10.1016/0014-5793(96)00868-x.
The Id family of helix-loop-helix proteins function as negative regulators of DNA binding, basic helix-loop-helix proteins in the regulation of cell growth and differentiation. We report here on the identification of a 17 kDa variant of the 14 kDa Id-3 protein termed Id-3L (long version) which possesses a unique 60 amino acid carboxy-terminus generated by read through of a 'coding intron' and alternative splicing. Northern analysis revealed expression of a minor 1.1 kb Id-3L transcript together with the predominant 0.95 kb Id-3 transcript in the majority of adult human tissues analysed. The variant Id-3L protein is functionally distinguishable from conventional Id-3 since in in vitro DNA mobility shift assays, it was greatly impaired in its ability to abrogate binding of the basic helix-loop-helix protein, E47, to an E box recognition sequence.
螺旋-环-螺旋蛋白的Id家族作为DNA结合的负调控因子，在细胞生长和分化的调控中对碱性螺旋-环-螺旋蛋白起作用。我们在此报告了一种14 kDa的Id-3蛋白的17 kDa变体，称为Id-3L（长版本）的鉴定结果，它具有一个独特的60个氨基酸的羧基末端，该末端是通过一个“编码内含子”的通读和可变剪接产生的。Northern分析显示，在大多数被分析的成人组织中，除了主要的0.95 kb Id-3转录本外，还存在少量的1.1 kb Id-3L转录本的表达。变异的Id-3L蛋白在功能上与传统的Id-3不同，因为在体外DNA迁移率变动分析中，它在消除碱性螺旋-环-螺旋蛋白E47与E盒识别序列结合的能力方面受到极大损害。
