Antagonistic interplay of Swi1 and Tup1 on filamentous growth of Candida albicans.
Candida albicans is a polymorphic human opportunistic pathogen in which the Swi-Snf complex functions as an activator whereas Tup1 acts as a general repressor during the yeast-hyphae transition. In Saccharomyces cerevisiae, the interplay between the Swi-Snf complex and the Tup1-Ssn6 repressive complex regulates the balance between active and repressed chromatin structures of a number of genes. To study the interplay between Candida albicans Swi1 and Tup1 and their effects on morphogenesis, we analyzed phenotypes of swi1/swi1, tup1/tup1 and swi1/swi1 tup1/tup1 mutants under various growth conditions. The swi1/swi1 mutant failed to form true hyphae, whereas the tup1/tup1 mutant exhibited constitutive filamentous growth. Deletion of SWI1 in the tup1/tup1 mutant completely blocked hyphal growth under all the conditions examined. Under aerobic conditions, the swi1/swi1 tup1/tup1 mutant most resembled the swi1/swi1 mutant in phenotype, actin polarization and gene expression pattern. In invaded agar, the double mutant showed similar phenotypes as the swi1/swi1 mutant, while under embedded conditions, it grew as a pseudohypha-like form different from that of the wild-type strain, swi1/swi1 or tup1/tup1 mutants. These results suggest that Swi1 may play a dominant role by antagonizing the repressive effect of the Tup1 on hyphal development in C. albicans.
State Key Laboratory of Molecular Biology, Institute of Biochemistry and Cell Biology, SIBS, Chinese Academy of Sciences, Shanghai, China.
Xuming
X
Mao
Yandong
Y
Li
Huafeng
H
Wang
Fang
F
Cao
Jiangye
J
Chen
D000199:Actins / Q000378:metabolism; D000332:Aerobiosis; D002176:Candida albicans / Q000166:cytology* / Q000235:genetics / Q000254:growth & development* / Q000502:physiology; D005656:Fungal Proteins / Q000235:genetics / Q000378:metabolism*; D017353:Gene Deletion; D020869:Gene Expression Profiling; D015966:Gene Expression Regulation, Fungal; D025301:Hyphae / Q000166:cytology* / Q000235:genetics / Q000254:growth & development* / Q000502:physiology
D000199:Actins; D005656:Fungal Proteins