Department of Microbiology, Faculty of Medicine, Chiang Mai University, Chiang Mai, Thailand.
Department of Genetics, Faculty of Science, University of Melbourne, Victoria, Australia.
PLoS One. 2015 Apr 13;10(4):e0122728. doi: 10.1371/journal.pone.0122728. eCollection 2015.
Talaromyces marneffei (Basionym: Penicillium marneffei) is a significant opportunistic fungal pathogen in patients infected with human immunodeficiency virus in Southeast Asia. T. marneffei cells have been shown to become melanized in vivo. Melanins are pigment biopolymers which act as a non-specific protectant against various stressors and which play an important role during virulence in fungi. The synthesis of the two most commonly found melanins in fungi, the eumelanin DOPA-melanin and the allomelanin DHN-melanin, requires the action of laccase enzymes. The T. marneffei genome encodes a number of laccases and this study describes the characterization of one of these, pbrB, during growth and development. A strain carrying a PbrB-GFP fusion shows that pbrB is expressed at high levels during asexual development (conidiation) but not in cells growing vegetatively. The pbrB gene is required for the synthesis of DHN-melanin in conidia and when deleted results in brown pigmented conidia, in contrast to the green conidia of the wild type.
马尔尼菲青霉（原名：彭萨凡青霉）是东南亚地区人类免疫缺陷病毒感染患者中一种重要的机会性真菌病原体。研究表明，马尔尼菲青霉细胞在体内会变成黑色素。黑色素是一种色素生物聚合物，可作为一种非特异性保护剂，抵抗各种应激源，并在真菌的毒力中发挥重要作用。真菌中两种最常见的黑色素，即多巴黑色素和 DHN 黑色素，的合成需要漆酶的作用。马尔尼菲青霉基因组编码了许多漆酶，本研究描述了其中一种漆酶 pbrB 在生长和发育过程中的特征。携带 PbrB-GFP 融合蛋白的菌株表明，pbrB 在无性发育（分生孢子形成）过程中高水平表达，但在营养生长的细胞中不表达。pbrB 基因是分生孢子中 DHN-黑色素合成所必需的，当缺失时会导致棕色色素分生孢子，与野生型的绿色分生孢子形成对比。
