白念珠菌蛋白磷酸酯酶CaPph3和调节亚基CaPsy2在调节菌丝发育中的作用

The function of protein phosphatase CaPph3 and regulatory subunit CaPsy2 in the regulation of the filamentous growth of Candida albicans

目的:研究白念珠菌蛋白磷酸酯酶CaPph3及调节亚基CaPsy2在调控白念珠菌菌丝发育过程中的作用。方法:利用遗传毒性试剂HU和MMS分别处理CaPPH3和CaPSY2缺失株,观察移除毒性试剂后缺失株的菌丝发育情况。结果:(1)缺失株的表型鉴定:在含有遗传毒性试剂MMS、HU以及CP平板上,与野生型菌株RM1000相比,CaPPH3缺失株、CaPSY2缺失株和CaPPH3 CaPSY2双缺失株均表现出明显生长缺陷,且各缺失株间差异不大。(2)缺失株对遗传毒性试剂敏感度测定:用MMS和HU处理各菌株后,野生型菌株的存活率约95%,而CaPPH3缺失株、CaPSY2缺失株和CaPPH3 CaPSY2双基因缺失株存活率明显下降,且相互之间差异不大。(3)缺失株菌丝发育实验:用0.020%MMS处理各菌株4小时后,野生型菌株RM1000还维持酵母态,而CaPPH3缺失株、CaPSY2缺失株和CaPPH3 CaPSY2双基因缺失株已出芽形成菌丝;而移除MMS后野生型菌株形成菌丝,6小时后不再延长,在菌丝顶端形成酵母态细胞,而CaPPH3、CaPSY2和CaPPH3 CaPSY2双基因缺失株仍维持菌丝态。用40 mmol/L HU处理各菌株4小时后,各菌株都维持酵母态;而移除HU后野生型菌株仍维持酵母态,而CaPPH3缺失株、CaPSY2缺失株和CaPPH3 CaPSY2双基因缺失株则会逐渐形成菌丝。结论:CaPph3和CaPsy2参与调节遗传毒性试剂诱导的白念珠菌的菌丝发育。

Objective： To study the function of protein phosphatase CaPph3 and the regulatory subunit CaPsy2 in the regulation of the filamentous growth of Candida albicans. Methods：The cells of Candida albicans were treated with HU and MMS,and then the filamentous growth was checked by microscope after the genotoxic agents were removed. Results：（1）The phenotype of the deletion mutants：Compared with wildtype, deletion mutants of CaPPH3, CaPSY2 and the double-gene deletion mutants for CaPPH3 and CaPTC2 showed similar hypersensitive to genotoxic agents MMS, HU and CP. （2） The sensitivity of deletion mutants to genotoxic agents： After the strains were treated with HU or MMS for 4 hours, the sur-vival rate of RM1000 strains was about 95% while the survival rate of the deletion mutants declined severely, and there was no obvious difference between these deletion mutants. （3）The filamentous growth of the deletion mutants： After the strains were treated with 0.020% MMS for 4 hours, the wildtype strains showed yeast form while the deletion mutants of CaPPH3, CaPSY2 and the double-gene deletion mutants for CaPPH3 and CaPTC2 showed filamentous form. Then after the MMS was washed out, the wildtype strains generated hypha gradually until the timeout after 6 hours and then generated buds, while the deletion mutants remained filamentous at the same time. The strains were also treated with 40 mM HU for 4 hours and they all showed yeast form. After the HU was washed out, the wildtype strains maitained yeast form until the timeout after 6 hours while the deletion mutants generated hypha gradually. Conclusion：CaPph3 and CaPsy2 play a role in the regulation of the filamentous growth induced by genetic toxic reagents in Candida albicans.