Calcineurin regulatory subunit is essential for virulence and mediates interactions with FKBP12-FK506 in Cryptococcus neoformans
Calcineurin regulatory subunit is essential for virulence and mediates interactions with FKBP12-FK506 in Cryptococcus neoformans
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DOI：
10.1046/j.1365-2958.2001.02295.x
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发表时间：
2001-02-01
影响因子：
3.6
通讯作者：
Heitman, J
中科院分区：
文献类型：
--
作者：
Fox, DS;Cruz, MC;Heitman, J
钙调磷酸酶是一种钙调蛋白调节的蛋白磷酸酶，是免疫抑制药物环孢素A和FK 506的靶点。钙调神经磷酸酶是由催化A亚基和调节B亚基组成的异源二聚体。在以前的研究中，钙调神经磷酸酶A同源物被确定，并显示为在37 degreesC下生长所需，因此为致病真菌新型隐球菌的毒力所需。在这里，我们确定了基因编码的钙调神经磷酸酶B调节亚基，并证明钙调神经磷酸酶a也需要在高温下生长和毒力。我们发现，FKR 1 -1突变，赋予显性FK 506耐药，结果从一个6 bp的重复产生两个氨基酸插入的钙调磷酸酶a的闩锁区。发现该突变在体内和体外均降低FKBP 12-FK 506与钙调磷酸酶的结合。基于FKBP 12-FK 506-钙调磷酸酶晶体结构的分子建模说明了该突变如何干扰药物与磷酸酶靶标的相互作用。总之，我们的研究揭示了钙调神经磷酸酶B在人类真菌病原体C的毒力和抗真菌药物作用中的核心作用。新人类
Calcineurin is a Ca2+-calmodulin-regulated protein phosphatase that is the target of the immunosuppressive drugs cyclosporin A and FK506. Calcineurin is a heterodimer composed of a catalytic A and a regulatory B subunit. In previous studies, the calcineurin A homologue was identified and shown to be required for growth at 37 degreesC and hence for virulence of the pathogenic fungus Cryptococcus neoformans. Here, we identify the gene encoding the calcineurin B regulatory subunit and demonstrate that calcineurin a is also required for growth at elevated temperature and virulence. We show that the FKR1-1 mutation, which confers dominant FK506 resistance, results from a 6 bp duplication generating a two-amino-acid insertion in the latch region of calcineurin a. This mutation was found to reduce FKBP12-FK506 binding to calcineurin both in vivo and in vitro, Molecular modelling based on the FKBP12-FK506-calcineurin crystal structure illustrates how this mutation perturbs drug interactions with the phosphatase target. In summary, our studies reveal a central role for calcineurin B in virulence and antifungal drug action in the human fungal pathogen C. neoformans.