FUNCTIONAL ANALYSIS OF PLAKIN FAMILY PROTEINS

Plakin家族蛋白包括促丝Plakin、plectin、bulous pemphigoid antigen 1（BPAG1）、envoplakin、periplakin和depiplakin，它们具有氨基端球形结构域、无中心结构域和羧基端球形结构域，其中氨基端球形结构域介导与质膜的相互作用，羧基端球形结构域介导与中间丝的相互作用。我们发现，稳定转染包膜蛋白的小鼠角化细胞在培养系统中表现出显著的角化/分化。这使我们提出plakin家族蛋白可以介导角化细胞的角化/分化。我们的实验目的是对plakin家族蛋白与表皮角质细胞角质化/分化的关系进行更详细的研究。结果：1；Envoplakin/Periplakin稳定转染的小鼠角化细胞在三维角化细胞培养系统中表现出显著的角化/分化。关于其他方面，一系列的实验正在进行中。在表皮恶性肿瘤中，plakin家族蛋白的定位和谷氨酰胺转胺酶的原位活性明显受到干扰，而在良性肿瘤中则没有明显的变化。

Plakin family proteins have aroleascytolinker proteins, which includes desmoplakin, plectin, Bullous pemphigoid antigen 1(BPAG1), envoplakin, periplakin andepiplakin They have an amino-terminal globular domain, acentrarod domain and a carboxy-terminalglobular domain The an amino-terminal globular domain mediating the interaction with the plasma membrane and the carboxy-terminalglobular domain associating with intermediate filaments. We find that the envoplakin stably transfected mouse keratinocytes showed remarkable keratinisation/differentiation in culture system. This led us to propose that the plakin family proteins can mediates keratinisation/differentiation of keratinocyte. The aim of our experiments was to carryout amoredetailed study about the relationship of plakin family proteins and epidermal keratinocyte Keratinisation/differentiation.Results : 1.Envoplakin/Periplakin stably transfected mouse keratinocytes showed remarkable keratinisation/differentiation in 3-D keratinocyte culture system. About the other plakins, series of the experiment is now on the way.2.In the epidermal malignant tumors, the localization of the plakin family proteins and in situ activity of transglutaminase were remarkably disturbed, but in the benign tumors were not.