Sidis Y, Horseman N D
Department of Physiology and Biophysics, University of Cincinnati College of Medicine, Ohio 45267.
Endocrinology. 1994 Apr;134(4):1979-85. doi: 10.1210/endo.134.4.8137767.
Several growth factors and cytokines have been proposed to act through signaling pathways related by their dependence on tyrosine phosphorylation of latent transcription factors, and their use of similar transcription factor binding sites. Related mechanisms have previously not been reported for prolactin, growth hormone, or any other glandular hormone. We have identified sequences in the annexin Icp35 gene that are related to regulatory sequences in mammary gland milk protein genes, and then used DNA binding assays to show that PRL induces transient expression of factors specific for these sequences. The sequences in question are partially related to the core homology of the interferon (IFN)gamma-activated sequence (GAS). Considering that the prolactin-regulated factors might be related to the p91 component of IFN gamma-activated factor, we used immunoassays to show that prolactin induced tyrosine phosphorylation of a protein that comigrated with immunoreactive relatives of p91, and that antibody to p91 specifically interfered with the prolactin-induced binding activity on the annexin Icp35 gene.
几种生长因子和细胞因子被认为是通过与潜在转录因子酪氨酸磷酸化相关的信号通路发挥作用的，并且它们使用相似的转录因子结合位点。此前尚未有关于催乳素、生长激素或任何其他腺激素的相关机制的报道。我们在膜联蛋白Icp35基因中鉴定出了与乳腺乳蛋白基因调控序列相关的序列，然后通过DNA结合试验表明催乳素可诱导针对这些序列的特异性因子的瞬时表达。所讨论的序列与干扰素（IFN）γ激活序列（GAS）的核心同源性部分相关。考虑到催乳素调节的因子可能与IFNγ激活因子的p91成分相关，我们使用免疫测定法表明催乳素可诱导一种与p91免疫反应性相关蛋白共迁移的蛋白发生酪氨酸磷酸化，并且针对p91的抗体可特异性干扰催乳素诱导的膜联蛋白Icp35基因的结合活性。
