Wang D S, Shaw R, Hattori M, Arai H, Inoue K, Shaw G
University of Florida College of Medicine, Department of Neuroscience, Gainesville, Florida 32610, USA.
Biochem Biophys Res Commun. 1995 Apr 17;209(2):622-9. doi: 10.1006/bbrc.1995.1545.
In previous experiments we demonstrated an interaction between certain pleckstrin homology (PH) domains and regions containing the so-called WD40 (or beta-transducin) repeats of the beta subunit of trimeric G-proteins (G beta), a finding we here extend to the PH domains of the src-related tyrosine kinase TecIIa and the GTPase dynamin. To examine the possibility that WD40 repeats in molecules other than G beta might also bind PH domains we examined PAFAH-45, the protein product of the Lis-1 gene, which contains 7 WD40 repeats. We found that 1) Purified PAFAH-45 binds PH domain constructs in vitro. 2) Protein constructs expressing all 7 WD40 repeats of PAFAH-45 but lacking the N-terminal non WD40 region also bind PH domains of beta-adrenergic receptor kinase, beta-spectrin, TecIIa and dynamin but with a differing hierarchy of affinities than that seen with G beta. 3). PAFAH-45 WD40 repeats will reduce the binding of PH domains to brain G beta and brain G beta gamma will reduce the binding of PH domains to PAFAH-45. These data support the hypothesis that PH domain/WD40 interactions are involved in a wide variety of important protein/protein interactions.
在先前的实验中，我们证明了某些普列克底物蛋白同源性（PH）结构域与三聚体G蛋白（Gβ）β亚基中含有所谓WD40（或β-转导蛋白）重复序列的区域之间存在相互作用，我们在此将这一发现扩展至与src相关的酪氨酸激酶TecIIa和GTP酶发动蛋白的PH结构域。为了研究除Gβ之外的其他分子中的WD40重复序列是否也可能结合PH结构域，我们检测了Lis-1基因的蛋白产物PAFAH-45，它含有7个WD40重复序列。我们发现：1）纯化的PAFAH-45在体外能结合PH结构域构建体。2）表达PAFAH-45所有7个WD40重复序列但缺少N端非WD40区域的蛋白构建体也能结合β-肾上腺素能受体激酶、β-血影蛋白、TecIIa和发动蛋白的PH结构域，但亲和力的层次结构与Gβ不同。3）PAFAH-45的WD40重复序列会减少PH结构域与脑Gβ的结合，而脑Gβγ会减少PH结构域与PAFAH-45的结合。这些数据支持了以下假说，即PH结构域/WD40相互作用参与了多种重要的蛋白质/蛋白质相互作用。
