Polymorphism: Antifungal Drug Resistance & Adaptation in Candida

项目摘要 聚合重复序列，通常只由一种或两种不同的氨基酸组成，在许多 真菌蛋白质，特别是那些具有调节功能的蛋白质。这些“Polyx”区域可以是高度多态的， DNA复制过程中重复单位之间滑动的结果。需要检验的一般假设 这就是Polyx多态填补了传统突变和表观遗传学之间的适应缺口。这个 这种R21的特定焦点是机会酵母光滑假丝酵母，它以其发育能力而闻名 对抗真菌的氮唑类药物和最近的棘球菌素类药物的耐药性。而C. 光肩星天牛Pdr1或FKS蛋白介导对这些药物的高水平抗性，有新的证据表明 这些突变伴随着其他基因变化，这些基因变化导致抗真菌敏感性降低或 耐受性，或补偿与Pdr1/FKS突变相关的适应性降低。在目标1中， 与唑或棘球绦虫敏感性相关的36种Polyx蛋白的多态性将在7唑中进行评估 耐药和6株棘球绦虫耐药临床分离株的流行病学或系统发育关系 匹配的敏感菌株。初步研究已经在多聚Q区域发现了一个这样的多态 转录抑制因子Tup1a与棘球绦虫杀伤率降低16-32倍相关。目标2将 通过使用基因替换来构建仅在Polyx上不同的菌株来直接测试这些相关性 一种抗真菌相关蛋白的含量，然后是敏感性和适合性分析。如果将军 假说得到支持，未来的研究将有必要评估Polyx多态在其他 真菌感染的各个方面，包括组织特异性黏附、生物膜形成和免疫逃避。

Project Abstract Polymeric repeats, typically consisting of only one or two different amino acids, are found within many fungal proteins, particularly those with regulatory functions. These “polyX” regions can be highly polymorphic, a consequence of slippage between repeat units during DNA replication. The general hypothesis to be tested here is that polyX polymorphisms fill the adaptation gap between conventional mutation and epigenetics. The specific focus of this R21 is the opportunistic yeast Candida glabrata, well known for its ability to develop resistance to antifungal azoles and, more recently, echinocandins. While single base mutations within C. glabrata Pdr1 or Fks proteins mediate high level resistance to these agents, there is emerging evidence that these mutations are accompanied by other genetic changes that confer reduced antifungal susceptibility or tolerance, or compensate for the decreased fitness associated with Pdr1/Fks mutation. In Aim 1, the polymorphism of 36 polyX proteins relevant to azole or echinocandin susceptibility will be assessed in 7 azole resistant and 6 echinocandin-resistant clinical isolates relative to their epidemiologically or phylogenetically matched susceptible isolates. Preliminary studies have identified one such polymorphism in the polyQ region of transcriptional repressor Tup1A that correlates with 16 to 32-fold reduced echinocandin killing. Aim 2 will directly test these correlations by using gene replacement to construct strains that differ only in the polyX content of an antifungal-relevant protein, followed by susceptibility and fitness assays. If the general hypothesis is supported, future studies would be warranted to evaluate the role of polyX polymorphism in other aspects of fungal infection, including tissue-specific adhesion, biofilm formation, and immune evasion.