Heitman Lab Members

Felicia Walton The Wellcome Trust/CR UK Gurdon Institute University of Cambridge Tennis Court Road Cambridge CB2 1QR Tel. +44 (0) 1223 334096 Fax: +44 (0) 1223 334089

I was an undergraduate at Duke, and graduated in Spring 2007 with majors in biology and chemistry. I began working in Dr. Heitman's lab in 2004, and was mentored by Dr. Alex Idnurm. My first project involved screening over 10,000 mutants for altered melanin production, a key virulence factor in Cryptococcus neoformans. As a result of the work, five new genes were identified in the melanin biosynthesis pathway and their cellular roles elucidated, including proteins involved in changing gene expression, transporting metal ions, and synthesizing the cell wall (Walton et al., 2005). In my second project, I studied mutants that we found in our screenings that have unusual morphologies. Pathogens often change morphologies during their infectious cycles and regulation of this process is an interesting avenue of research.  In studying how Cryptococcus regulates its morphology and divides to proliferate, I discovered proteins crucial to the organism's ability to resist certain drugs, to reproduce at human body temperature, and to complete the last step in cell division (Walton et al., 2006). These mutants each contain disruptions in genes that are homologues of members of a conserved signaling pathway named RAM for regulation of Ace2 activity and cellular morphogenesis. My latest research continued to focus on this pathway and its interaction with the calcineurin pathway.  

Publications:

1.   Walton, F. , Idnurm, A., Heitman, J. Novel gene functions required for melanization of the human pathogen          Cryptococcus neoformans. Molecular Microbiology. 2005 Sep;57(5):1381-96.

2.   Walton, F. , Heitman, J., Idnurm, A. Conserved Elements of the RAM Signaling Pathway Establish Cell Polarity in the Basidiomycete Cryptococcus neoformans in a Divergent Fashion from Other Fungi. Molecular Biology of the Cell. 2006 Jun 14.