Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, São Paulo, Brazil.
PLoS One. 2012;7(5):e37591. doi: 10.1371/journal.pone.0037591. Epub 2012 May 23.
Aspergillus fumigatus is a primary and opportunistic pathogen, as well as a major allergen, of mammals. The Ca(+2)-calcineurin pathway affects virulence, morphogenesis and antifungal drug action in A. fumigatus. Here, we investigated three components of the A. fumigatus Ca(+2)-calcineurin pathway, pmcA,-B, and -C, which encode calcium transporters. We demonstrated that CrzA can directly control the mRNA accumulation of the pmcA-C genes by binding to their promoter regions. CrzA-binding experiments suggested that the 5'-CACAGCCAC-3' and 5'-CCCTGCCCC-3' sequences upstream of pmcA and pmcC genes, respectively, are possible calcineurin-dependent response elements (CDREs)-like consensus motifs. Null mutants were constructed for pmcA and -B and a conditional mutant for pmcC demonstrating pmcC is an essential gene. The ΔpmcA and ΔpmcB mutants were more sensitive to calcium and resistant to manganese and cyclosporin was able to modulate the sensitivity or resistance of these mutants to these salts, supporting the interaction between calcineurin and the function of these transporters. The pmcA-C genes have decreased mRNA abundance into the alveoli in the ΔcalA and ΔcrzA mutant strains. However, only the A. fumigatus ΔpmcA was avirulent in the murine model of invasive pulmonary aspergillosis.
烟曲霉是哺乳动物的主要病原体、机会性病原体和主要过敏原。钙调神经磷酸酶途径影响烟曲霉的毒力、形态发生和抗真菌药物作用。在这里，我们研究了烟曲霉钙调神经磷酸酶途径的三个成分，即 pmcA、-B 和 -C，它们编码钙转运蛋白。我们证明，CrzA 可以通过结合到它们的启动子区域直接控制 pmcA-C 基因的 mRNA 积累。CrzA 结合实验表明，pmcA 和 pmcC 基因上游的 5'-CACAGCCAC-3'和 5'-CCCTGCCCC-3'序列分别是可能的钙调神经磷酸酶依赖性反应元件（CDRE）样共有基序。构建了 pmcA 和 -B 的缺失突变体和 pmcC 的条件性突变体，证明 pmcC 是一个必需基因。ΔpmcA 和 ΔpmcB 突变体对钙更敏感，对锰有抗性，环孢菌素能够调节这些突变体对这些盐的敏感性或抗性，支持钙调神经磷酸酶与这些转运蛋白功能之间的相互作用。pmcA-C 基因在ΔcalA 和 ΔcrzA 突变株中的肺泡中 mRNA 丰度降低。然而，只有烟曲霉ΔpmcA 在侵袭性肺曲霉病的小鼠模型中丧失了毒力。
