Functional analysis of the C-treminal frangment of membrane-anchored growth factors

我们分析了典型的膜锚定生长因子proHB-EGF脱落引起的c端片段（CTF）信号的功能。我们发现：(1)proHB-EGF的CTF通过内吞作用内化到细胞质中，并通过逆行囊泡运输在核膜上定位；(2)CTF通过与基因抑制因子相互作用并调节促进细胞生长所必需的几种基因表达；(3)CTF信号在一些肿瘤细胞系中具有组成性活性。

We analyzed the function of C-terminal fragment (CTF) signals which are evoked by the shedding of a representative membrane-anchored growth factor proHB-EGF. We found that (1) the CTF of proHB-EGF was internalized into cytosol by endocytosis and localized at the innernuclear membrane by retrograde vesicle transport, (2) the CTF regulated several gene expression essential for cell growth promotion by interacting with and regulating gene repressors, and (3) the CTF signal was constitutively active in some tumor cell lines.