National Key Program of Microbiology and Department of Microbiology, College of Life Sciences, Nankai University, Tianjin, China.
Appl Environ Microbiol. 2012 Jan;78(1):21-7. doi: 10.1128/AEM.06072-11. Epub 2011 Oct 21.
Fungal laccases have been widely used in industry. The expression of laccase often is repressible by the primary carbon source glucose in many fungi. The underlying basis is largely unclear. We demonstrate here that a gene, TSP2-1, was required for laccase repression by glucose in the basidiomycete Cryptococcus neoformans. TSP2-1 encodes a Tsp2-type tetraspanin. The disruption of TSP2-1 resulted in constant melanin formation and the expression of the laccase gene LAC1. This derepression phenotype was restorable by 10 mM exogenous cyclic AMP (cAMP). A capsule defect in the mutant tsp2-1Δ also was restored by cAMP. The results indicate an interaction of Tsp2-1 with the cAMP-dependent protein kinase A (PKA) pathway that has been shown to modulate laccase repression and capsule biosynthesis in this fungus. Other roles of TSP2-1, e.g., in maintaining cell membrane integrity and stress resistance, also were defined. This work reveals a Tsp2-1-dependent glucose repression in C. neoformans. The function of Tsp2-type tetraspanin Tsp2-1 is described for the first time.
真菌漆酶已被广泛应用于工业领域。在许多真菌中，漆酶的表达通常会受到主要碳源葡萄糖的抑制。其潜在的基础在很大程度上还不清楚。在这里，我们证明了在担子菌新生隐球菌中，一个名为 TSP2-1 的基因对于葡萄糖对漆酶的抑制是必需的。TSP2-1 编码一个 Tsp2 型四跨膜蛋白。TSP2-1 的缺失导致黑色素的持续形成和漆酶基因 LAC1 的表达。这种去抑制表型可以通过 10 mM 外源环腺苷酸 (cAMP) 恢复。突变体 tsp2-1Δ中的荚膜缺陷也可以通过 cAMP 恢复。结果表明 Tsp2-1 与已被证明可调节该真菌中漆酶抑制和荚膜生物合成的 cAMP 依赖性蛋白激酶 A (PKA) 途径相互作用。TSP2-1 的其他作用，例如维持细胞膜完整性和抗应激能力，也得到了定义。这项工作揭示了新生隐球菌中的 Tsp2-1 依赖性葡萄糖抑制。首次描述了 Tsp2 型四跨膜蛋白 Tsp2-1 的功能。
