Tianyuan Wang is a Ph.D. student in the Department of Biological Sciences at the University of Texas at Dallas, under the guidance of Dr. Li Zhang. The Zhang lab is interested in investigating the molecular mechanisms underlying heme signaling in eukaryotic cells. Tianyuan is currently focusing on the study of heme regulation on yeast transcriptional factor Gis1 and C. albicans orf19.2743, which are highly homologous to the mammalian JmjC domain-containing KDM4B protein. Her research interests also include heme regulation of KDM4 subfamily demethylase activity and heme availability in lung cancer initiation and tumorigenicity. Prior to joining the graduate school at the University of Texas at Dallas, Tianyuan obtained her bachelor degree in Biological Sciences at China Agricultural University, where she worked as a research assistant and was involved in the project “proteomic analysis of Arabidopsis response to environmental stress”.
Heme is an essential iron source and a metallonutrient for organisms ranging from pathogenic bacteria to humans. Heme also serves as a small signaling molecule that directly regulates many molecular and cellular processes, including gene transcription and circadian rhythm. C. albicans expresses several heme assimilations CFEM and hemophore proteins for scavenging heme. Mutants of these proteins are defective for invasive growth of C. albicans. Interestingly, a systematic genetic screen showed that heterozygous disruption of the C. albicans orf19.2743 reduces invasive growth. Orf19.2743 is a JmjC domain-containing protein that is homologous to S. cerevisiae Gis1, belonging to the KDM4 subfamily of proteins. Gis1 is a multifunctional transcriptional regulator possessing histone demethylase activity. Our recent data showed that heme regulates the transcriptional and demethylase activities of Gis1. Further, we found that histone demethylase activities of mammalian KDM4A and KDM4C are also heme-regulated. Based on those results, we postulate that heme regulates the activity of C. albicans KDM4 homolog orf19.2743. Experiments are underway to test this hypothesis and ascertain the
importance of heme and orf19.2743 in C. albicans virulence.