@article{MottolaRamirezZavalaHuenningeretal.2021, author = {Mottola, Austin and Ram{\´i}rez-Zavala, Bernardo and H{\"u}nninger, Kerstin and Kurzai, Oliver and Morschh{\"a}user, Joachim}, title = {The zinc cluster transcription factor Czf1 regulates cell wall architecture and integrity in Candida albicans}, series = {Molecular Microbiology}, volume = {116}, journal = {Molecular Microbiology}, number = {2}, doi = {10.1111/mmi.14727}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-259583}, pages = {483-497}, year = {2021}, abstract = {The fungal cell wall is essential for the maintenance of cellular integrity and mediates interactions of the cells with the environment. It is a highly flexible organelle whose composition and organization is modulated in response to changing growth conditions. In the pathogenic yeast Candida albicans, a network of signaling pathways regulates the structure of the cell wall, and mutants with defects in these pathways are hypersensitive to cell wall stress. By harnessing a library of genetically activated forms of all C. albicans zinc cluster transcription factors, we found that a hyperactive Czf1 rescued the hypersensitivity to cell wall stress of different protein kinase deletion mutants. The hyperactive Czf1 induced the expression of many genes with cell wall-related functions and caused visible changes in the cell wall structure. C. albicans czf1Δ mutants were hypersensitive to the antifungal drug caspofungin, which inhibits cell wall biosynthesis. The changes in cell wall architecture caused by hyperactivity or absence of Czf1 resulted in an increased recognition of C. albicans by human neutrophils. Our results show that Czf1, which is known as a regulator of filamentous growth and white-opaque switching, controls the expression of cell wall genes and modulates the architecture of the cell wall.}, language = {en} } @phdthesis{Mottola2021, author = {Mottola, Austin}, title = {Molecular characterization of the SNF1 signaling pathway in \(Candida\) \(albicans\)}, doi = {10.25972/OPUS-23809}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-238098}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2021}, abstract = {The fungus Candida albicans is a typical member of the human microbiota, where it usually behaves as a commensal. It can also become pathogenic; often causing minor superficial infections in healthy people, but also potentially fatal invasive systemic infections in immunocompromised people. Unfortunately, there is only a fairly limited set of antifungal drugs, and evolution of drug resistance threatens their efficacy. Greater understanding of the mechanisms that C. albicans uses to survive in and infect the host can uncover candidate targets for novel antifungals. Protein kinases are central to a vast array of signalling pathways which govern practically all aspects of life, and furthermore are relatively straightforward to design drugs against. As such, investigation and characterization of protein kinases in C. albicans as well as their target proteins and the pathways they govern are important targets for research. AMP-activated kinases are well conserved proteins which respond to energy stress; they are represented in yeasts by the heterotrimeric SNF1 complex, which responds primarily to the absence of glucose. In this work, the SNF1 pathway was investigated with two primary goals: identify novel targets of this protein kinase and elucidate why SNF1 is essential. Two approaches were used to identify novel targets of SNF1. In one, suppressor mutants were evolved from a strain in which SNF1 activity is reduced, which exhibits defects in carbon source utilization and cell wall integrity. This revealed a suppressor mutation within SNF1 itself, coding for the catalytic subunit of the complex - SNF1Δ311-316. The second approach screened a library of artificially activated zinc cluster transcription factors, identifying Czf1 as one such transcription factor which, upon artificial activation, restored resistance to cell wall stress in a mutant of the SNF1 pathway. Finally, a, inducible gene deletion system revealed that SNF1 is not an essential gene.}, subject = {candida albicans}, language = {en} }