Abstract：
Protein kinases are critical regulatory proteins in both prokaryotes and eukaryotes. Accordingly, protein kinases represent a common drug target for a wide range of human diseases. Therefore, understanding protein kinase function in human pathogens such as the fungus Candida albicans is likely to extend our knowledge of its pathobiology and identify new potential therapies. To facilitate the study of C. albicans protein kinases, we constructed a library of 99 non-essential protein kinase homozygous deletion mutants marked with barcodes in the widely used SN genetic background. Here, we describe the construction of this library and the characterization of the competitive fitness of the protein kinase mutants under 11 different growth and stress conditions. We also screened the library for protein kinase mutants with altered filamentation and biofilm formation, two critical virulence traits of C. albicans. An extensive network of protein kinases governs these virulence traits in a manner highly dependent on the specific environmental conditions. Studies on specific protein kinases revealed that (i) the cell wall integrity MAPK pathway plays a condition-dependent role in filament initiation and elongation; (ii) the hyper-osmolar glycerol MAPK pathway is required for both filamentation and biofilm formation, particularly in the setting of in vivo catheter infection; and (iii) Sok1 is dispensable for filamentation in hypoxic environments at the basal level of a biofilm but is required for filamentation in normoxia. In addition to providing a new genetic resource for the community, these observations emphasize the environmentally contingent function of C. albicans protein kinases.IMPORTANCECandida albicans is one of the most common causes of fungal disease in humans for which new therapies are needed. Protein kinases are key regulatory proteins and are increasingly targeted by drugs for the treatment of a wide range of diseases. Understanding protein kinase function in C. albicans pathogenesis may facilitate the development of new antifungal drugs. Here, we describe a new library of 99 protein kinase deletion mutants to facilitate the study of protein kinases. Furthermore, we show that the function of protein kinases in two virulence-related processes, filamentation and biofilm formation, is dependent on the specific environmental conditions.
摘要：
蛋白激酶是原核生物和真核生物中的关键调节蛋白。因此，蛋白激酶代表了广泛的人类疾病的常见药物靶标。因此,了解蛋白激酶在真菌白色念珠菌等人类病原体中的功能可能会扩展我们对其病理生物学的了解并确定新的潜在疗法。为了促进白色念珠菌蛋白激酶的研究，我们在广泛使用的SN遗传背景下构建了99个标记有条形码的非必需蛋白激酶纯合缺失突变体的文库。这里,我们描述了该文库的构建以及蛋白激酶突变体在11种不同生长和胁迫条件下的竞争适应性特征。我们还筛选了具有改变的成丝和生物膜形成的蛋白激酶突变体的文库，白色念珠菌的两个关键毒力性状。广泛的蛋白激酶网络以高度依赖于特定环境条件的方式控制这些毒力性状。对特定蛋白激酶的研究表明（i）细胞壁完整性MAPK途径在细丝的起始和延伸中起着条件依赖性的作用；（ii）高渗性甘油MAPK途径是成丝和生物膜形成所必需的，特别是在体内导管感染的情况下；（iii）Sok1对于在生物膜基础水平的低氧环境中的成丝是不必要的，但对于在常氧条件下的成丝是必需的。除了为社区提供新的遗传资源，这些观察结果强调了白色念珠菌蛋白激酶的环境偶然功能。重要的白色念珠菌是人类真菌病的最常见原因之一，需要新疗法。蛋白激酶是关键的调节蛋白,并且越来越多地被用于治疗多种疾病的药物靶向。了解蛋白激酶在白色念珠菌发病机制中的功能可能有助于开发新的抗真菌药物。这里,我们描述了一个99个蛋白激酶缺失突变体的新文库，以促进蛋白激酶的研究。此外，我们表明蛋白激酶在两个毒力相关过程中的功能，成丝和生物膜形成，取决于具体的环境条件。
