Department of Dermatology, The Third Affiliated Hospital of Sun Yat-sen University, No. 600 TianHe Road, TianHe District, Guangzhou 510630, P.R. China.
Microb Pathog. 2010 Feb;48(2):57-61. doi: 10.1016/j.micpath.2009.12.001. Epub 2009 Dec 11.
Trichophyton rubrum is the most common pathogen caused the dermatophytosis of nail and skin in human. The secreted proteases were considered to be the most important virulence factors. However, the substrates adaptation of T. rubrum secreted proteases is largely unknown. For the first time, we use the keratins from human nail and skin stratum corneum as the growth medium to investigate the different expression patterns of T. rubrum secreted endoproteases genes. During grow in both keratin-containing media SUB7 and MEP2 were the highest expressed gene in each family. These results indicated that SUB7 and MEP2 may be the dominant endoproteases secreted by T. rubrum during host infection and the other proteases may play a supplementary role. The direct comparison of T. rubrum grown on skin and nail medium showed different substrate favorite of secreted endoproteases. The genes MEP2, SUB5, SUB2 and SUB3 were more active during growth in skin medium, possibly these proteases have a higher affinity for skin original keratins. While the structures of SUB1, SUB4, and MEP4 maybe more suitable for the degradation of nail original keratins. This work presents useful molecular details for further understanding the pathogenesis of secreted proteases and the wide adaptation of T. rubrum.
红色毛癣菌是导致人类皮肤和指甲癣的最常见病原体。分泌的蛋白酶被认为是最重要的毒力因子。然而，红色毛癣菌分泌蛋白酶的底物适应性在很大程度上尚不清楚。我们首次使用人指甲和皮肤角质层中的角蛋白作为生长培养基，研究了红色毛癣菌分泌内切蛋白酶基因的不同表达模式。在含有角蛋白的 SUB7 和 MEP2 培养基中生长时，每个家族中表达最高的基因是 SUB7 和 MEP2。这些结果表明，SUB7 和 MEP2 可能是红色毛癣菌在宿主感染期间分泌的主要内切蛋白酶，而其他蛋白酶可能发挥补充作用。红色毛癣菌在皮肤和指甲培养基上生长的直接比较表明，分泌的内切蛋白酶对不同底物有不同的偏好。在皮肤培养基中生长时，MEP2、SUB5、SUB2 和 SUB3 基因更活跃，可能这些蛋白酶对皮肤原始角蛋白具有更高的亲和力。而 SUB1、SUB4 和 MEP4 的结构可能更适合指甲原始角蛋白的降解。这项工作为进一步了解分泌蛋白酶的发病机制和红色毛癣菌的广泛适应性提供了有用的分子细节。
