表皮形态发生素(Epimorphin)与表皮形态发生

表皮形态发生素（epimorphin 又称为syntaxin2）是哺乳动物中高度保守的一个间质细胞表面膜蛋白，胞外区包含有1个19个氨基酸残基的部位（NL肽序列）,是其与细胞的结合位点，但发挥效应必须有其它的胞外区存在.目前,已经发现它调控下游的2个分子MMP3和C/EBPβ，但对于其信号通路还知之甚少，推测其可能通过直接或者间接磷酸化表皮生长因子受体（EGFR）而激发MAPK/ERK信号通路.它在多种表皮组织（包括肺、肠、肝、乳腺、胰腺、毛囊、胆囊、血管内皮等）的表皮形态发生，尤其是腺管状结构的形态发生过程中发挥重要作用.依靠极性和非极性2种不同的表达方式，epimorphin可以选择性介导腺管形态发生的2个关键过程:分支形态发生和腔形态发生，分支状形态发生涉及到腺管的发生和延展，腔形态发生涉及到腺管直径的增大.

Epimorphin and Epithelial Morphogenesis

Epimorphin (EPM, also called syntaxin2 ), a mesenchymal cell surface associated molecule, is highly conserved in mammalian.A cellular recognition sequence in the central portion of this molecule is termed NL peptide sequence, but it can’t induce the cellular responses without other extracellular regions. It has been known that EPM mediates morphogenesis through control of MMP3 and C/EBPβ, while it is known little about its signaling pathway. And it is proposed that EPM may trigger MAPK/ERK signaling pathway by phosphorylating epidermal growth factor receptor (EGFR) directly or indirectly. It functions as a key morphoregulator for many different epithelial cells including lung, intestine, liver, mammary gland, pancreas, hair follicle, gall bladder, endothelial cells，especially during the course of tubulogenesis. Depending upon the context of polar/ apolar presentation, EPM can selectively direct two key processes of tubulogenesis: branching morphogenesis and luminal morphogenesis, which is related to development and diameter expanding of lumen.