Roles for mRNA methylation and lncRNA in Candida mating and pathogenicity

描述(申请人提供)：本提案旨在了解mRNA甲基化和长非编码RNA在白念珠菌毒力中的作用，这是两种基因调控的分子机制。白色念珠菌通常是一种良性的共生体，但可以在健康的人身上引起皮肤和粘膜感染，在易感人群中引起危及生命的系统性感染。白念珠菌的致病性与其从酵母细胞中生长转换为丝状和生物膜形式生长的能力有关。虽然白色念珠菌不能有性繁殖，但它可以通过交配产生遗传多样性，这有可能导致毒力和耐药性的增加。为了确定新的治疗途径，需要更好地了解这些过程背后的分子机制。基因甲基化在几十年前就被发现了，但在其他真核生物中这种大规模的修饰直到最近才显现出来，它在基因调控中的功能还不清楚。在酿酒酵母中，IME4编码一种mRNA甲基转移酶，该酶在酿酒酵母减数分裂和丝状化过程中起着调节作用。白色念珠菌中存在IME4同源基因。长非编码RNA(LncRNA)是参与基因调控但不编码任何蛋白质的大转录本。酿酒酵母IME4的表达受反义lncRNA的调节，这种调节形式似乎在白色念珠菌中是保守的。初步数据表明，白色念珠菌中存在mRNA甲基化，IME4在丝状诱导条件下表达。此外，IME4的过表达抑制了丝状化。利用分子遗传学和高通量RNA测序，这项拟议的研究将确定白念珠菌IME4的mRNA靶标，评估其在交配、丝化和生物膜形成中的作用，并研究lncRNA对其调控。

DESCRIPTION (provided by applicant): This proposal is targeted at understanding the roles of mRNA methylation and long non-coding RNA, which are two molecular mechanisms of gene regulation, in Candida albicans virulence. C. albicans is a normally benign commensal, but can cause skin and mucosal membrane infections in healthy individuals, and life threatening systemic infections in susceptible individuals. C. albicans pathogenicity is linked to its ability o switch from growing in yeast-form cells to growing in filament and biofilm forms. While it cannot reproduce sexually, C. albicans can generate genetic diversity by mating, which has the potential to result in increased virulence and drug resistance. A better understanding of the molecular mechanisms behind these processes is required in order to identify new therapeutic avenues. mRNA methylation has been discovered decades ago, but the large scale of this modification in other eukaryotes has only recently became apparent, and its function in gene regulation is not yet understood. In Saccharomyces cerevisiae, IME4 encodes an mRNA methyltransferase, which plays a regulatory role in S. cerevisiae meiosis and filamentation. An IME4 homologue is present in C. albicans. Long non-coding RNA (lncRNA) are large transcripts that participate in gene regulation but do not encode any protein. S. cerevisiae IME4 expression is regulated by an antisense lncRNA, and this form of regulation appears to be conserved in C. albicans. Preliminary data indicates that mRNA methylation occurs in C. albicans, and that IME4 is expressed under filamentation inducing conditions. Furthermore, overexpression of IME4 inhibits filamentation. Using molecular genetics coupled with high throughput RNA sequencing, the proposed research will identify C. albicans IME4 mRNA targets, assess its role in mating, filamentation and biofilm formation, and study its regulation by lncRNA.