Approaching the functional annotation of fungal virulence factors using cross-species genetic interaction profiling.
Approaching the functional annotation of fungal virulence factors using cross-species genetic interaction profiling.
复制标题
DOI：
10.1371/journal.pgen.1003168
复制
发表时间：
2012
期刊：
影响因子：
4.5
通讯作者：
Madhani HD
中科院分区：
文献类型：
--
作者：
Brown JC;Madhani HD
In many human fungal pathogens, genes required for disease remain largely unannotated, limiting the impact of virulence gene discovery efforts. We tested the utility of a cross-species genetic interaction profiling approach to obtain clues to the molecular function of unannotated pathogenicity factors in the human pathogen Cryptococcus neoformans. This approach involves expression of C. neoformans genes of interest in each member of the Saccharomyces cerevisiae gene deletion library, quantification of their impact on growth, and calculation of the cross-species genetic interaction profiles. To develop functional predictions, we computed and analyzed the correlations of these profiles with existing genetic interaction profiles of S. cerevisiae deletion mutants. For C. neoformans LIV7, which has no S. cerevisiae ortholog, this profiling approach predicted an unanticipated role in the Golgi apparatus. Validation studies in C. neoformans demonstrated that Liv7 is a functional Golgi factor where it promotes the suppression of the exposure of a specific immunostimulatory molecule, mannose, on the cell surface, thereby inhibiting phagocytosis. The genetic interaction profile of another pathogenicity gene that lacks an S. cerevisiae ortholog, LIV6, strongly predicted a role in endosome function. This prediction was also supported by studies of the corresponding C. neoformans null mutant. Our results demonstrate the utility of quantitative cross-species genetic interaction profiling for the functional annotation of fungal pathogenicity proteins of unknown function including, surprisingly, those that are not conserved in sequence across fungi. HIV/AIDS patients, cancer chemotherapy patients, and organ transplant recipients are highly susceptible to infection by opportunistic fungal pathogens, organisms common in the environment that are harmless to normal individuals. Understanding how these pathogens cause disease requires the identification of genes required for virulence and the determination of their molecular function. Our work addresses the latter problem using the yeast Cryptococcus neoformans, which is estimated to cause 600,000 deaths annually worldwide in the HIV/AIDS population. We describe a method for determining gene function in which C. neoformans genes are expressed in deletion mutants of all nonessential genes of the well-studied model yeast S. cerevisiae. By examining the impact on growth (enhancement or suppression) we generated “cross-species” genetic interaction profiles. We compared these profiles to the published genetic interaction profiles of S. cerevisiae deletion mutants to identify those with correlated patterns of genetic interactions. We hypothesized that the known functions of S. cerevisiae genes with correlated profiles could predict the function of the pathogen gene. Indeed, experimental tests in C. neoformans for two pathogenicity genes of previously unknown function found the functional predictions obtained from genetic interaction profiles to be accurate, demonstrating the utility of the cross-species approach.
登录
查看更多内容
影响因子：
4.5
作者：
Hershberg R;Petrov DA
通讯作者：
Petrov DA
影响因子：
64.5
作者：
CHANT, J;HERSKOWITZ, I
通讯作者：
HERSKOWITZ, I
影响因子：
4.8
作者：
Ashrafi, K;Farazi, TA;Gordon, JI
通讯作者：
Gordon, JI
影响因子：
3.1
作者：
CROSS, CE;BANCROFT, GJ
通讯作者：
BANCROFT, GJ
荚膜独立的吞噬抑制机制在哺乳动物新生隐球菌感染中的主要作用。
影响因子：
30.3
作者：
Chun CD;Brown JCS;Madhani HD
通讯作者：
Madhani HD