Date on Master's Thesis/Doctoral Dissertation


Document Type

Doctoral Dissertation

Degree Name

Ph. D.



Degree Program

Biology, PhD

Committee Chair

Perlin, Michael

Committee Co-Chair (if applicable)

Remold, Susanna

Committee Member

Remold, Susanna

Committee Member

Running, Mark

Committee Member

Schultz, David

Committee Member

Samuelson, David

Author's Keywords

Ustilago maydis; spore; fungus


Signal transduction is a key aspect of biological life. Cell signaling involves a series of biochemical and molecular steps that regulate the normal cellular functions, and any disruption at any of these steps is likely to have substantial impacts on cell physiology. The current study was aimed at the characterization of ptn1 of Ustilago maydis, a basidiomycete fungus. When the U. maydis, ptn1 gene was either deleted or overexpressed, it was found that the deletion of this gene lead to reduced virulence, spore production, and germination rate; effects of the overexpression were more subtle or not discernable. Previous studies have indicated that two other signaling proteins, Rho1 and Pdc1, are physical interactors of Ptn1. The goal of the latter part of the present study was to explore the functional interaction of Ptn1 with Rho1 and Pdc1. Our experiments indicated a functional connection between these genes, especially in processes that are related to stress tolerance, cellular morphology, and virulence of the fungus, suggesting that they may be elements of the same regulatory pathway. We predict that the pdc1 interaction with ptn1 may be the reverse of that of rho1 with ptn1. The current phenotypes of these mutant strains when considered in the context of already available information about the role of these genes in other systems indicate that they may be part of a pathway that modulates cytoskeletal rearrangements.