上皮细胞极性的建立和维持

The Epithelial Cell Polarity

细胞极性是生物中广泛存在的一个特征。上皮细胞是构成表皮、腺体、气管和消化道等组织的一类特化细胞。上皮细胞通常沿顶端-基底端轴向发生极化,形成紧密连接、粘附连接等胞间结构,同时细胞膜、细胞骨架和中心体、内膜系统、细胞核等也发生不对称分布,使细胞能行使分泌、吸收和屏障等多种重要的生理功能。有许多分子参与上皮细胞极性的建立和维持,其中最主要的是3个极性复合物,即Par-aPKC复合物,Scribble(Lg1-Dlg-Scrib)复合物和Crb(Crb-Pals-PATJ)复合物,三者共同配合发挥功能。

Cell polarity is a widely existing property in life. Epithelial cells are specialized cells commonly found in epidermis, secretory gland, airway, and digestive tract. They usually polarize along the apical-basal axis, with asymmetrically distributed plasma membrane structure, cytoskeletons, centrosome, endomembrane system, and nucleus. They also form intercellular junctions, such as tight junctions and adherens junctions. These properties render epithelial cells important physiological roles in secretion, absorption, and tissue barrier formation. Many proteins are involved in the establishment and maintenance of the epithelial cell polarity. Among them are three protein complexes termed the Par-aPKC complex, the Scribble （Lgl-Dlg-Scirb） complex, and the Crb （Crb-Pals- PATJ）