Regulation of a contact-dependent morphological transition in Candida albicans.
Abstract: The human
opportunistic pathogen Candida albicans undergoes a reversible morphological transition
between the yeast and hyphal states in response to a variety of signals. One such
environmental trigger is growth within a semisolid matrix. This growth condition is of
interest because it may mimic the growth of C. albicans in contact with host tissue
within its natural environment. Du... read morering growth within a semisolid matrix, hyphal growth
is positively regulated by the transcriptional regulator Czf1p and negatively by a
second key transcriptional regulator, Efg1p. Genetic studies indicate that Czf1p, a
member of the zinc-cluster family of transcriptional regulators characterized by a
Zn2Cys6 domain, exerts its function by opposing the inhibitory influence of Efg1p on
matrix-induced filamentous growth. We examined the importance of the two known
activities of Czf1p, DNA-binding and interaction with Efg1p. We found that the two
activities of Czf1p were separable by mutation allowing us to demonstrate that the DNA-
binding activity of Czf1p was essential for its role as a positive regulator of
morphogenesis. Surprisingly, however, interactions with Efg1 appeared to be largely
dispensable. Our studies provide the first evidence of a key role for the DNA-binding
activity of Czf1p in the morphological yeast-to-hyphal transition triggered by matrix-
Thesis (Ph.D.)--Tufts University, 2012.
Submitted to the Dept. of Genetics.
Advisor: Carol Kumamoto.
Committee: Abraham Sonenshein, Rob Jackson, Claire Moore, and Jane Lopilato.
Keywords: Biology, Genetics, and Microbiology.read less