Jaulin-Bastard Fanny, Nola Sébastien, Borg Jean-Paul
Laboratoire de Pharmacologie moléculaire, UMR 599 Inserm-Institut Paoli-Calmettes, 27, boulevard Leï Roure, 13009 Marseille, France.
Med Sci (Paris). 2005 Mar;21(3):267-72. doi: 10.1051/medsci/2005213267.
Cell proliferation and cell differentiation are balanced processes required for the correct development and maintenance of tissues, including epithelial tissues. Disruption of this balance by downregulation or loss of function of gatekeepers of epithelial homeostasis may unleash tumor suppressing activities leading ultimately to tumorigenesis. Among the newcoming actors involved in epithelial cell polarity, recent data shed light on the crucial role played by the LAP (LRR And PDZ) protein family. LAP proteins assemble receptors, cytoplasmic adaptors and enzymes in multimolecular networks important for the different steps of epithelial differentiation : adhesion, building of tight junctions and trafficking of proteins along the secretory pathway. Furthermore, genetic studies in invertebrates and vertebrates have installed LAP proteins not only as crucial determinants for epithelial integrity but also as key regulators of cell proliferation and embryonic development.
细胞增殖和细胞分化是组织（包括上皮组织）正确发育和维持所必需的平衡过程。上皮稳态守门人功能下调或丧失导致这种平衡被打破，可能会释放肿瘤抑制活性，最终导致肿瘤发生。在参与上皮细胞极性的新成员中，最近的数据揭示了LAP（富含亮氨酸重复序列和PDZ结构域）蛋白家族所起的关键作用。LAP蛋白在多分子网络中组装受体、细胞质衔接蛋白和酶，这些网络对上皮分化的不同步骤至关重要：黏附、紧密连接的形成以及蛋白质沿分泌途径的运输。此外，对无脊椎动物和脊椎动物的遗传学研究表明，LAP蛋白不仅是上皮完整性的关键决定因素，也是细胞增殖和胚胎发育的关键调节因子。
