Ziyin Li, Ph.D.
- Associate Professor
After receiving my Ph.D. degree from Institute of Genetics of the Chinese Academy of Sciences in Beijing, I was fascinated by the ubiquitin-proteasome system and joined Dr. C.C. Wang’s laboratory at University of California-San Francisco as a postdoc fellow. I established a relationship between the ubiquitin-proteasome system and cell cycle regulation in Trypanosoma brucei, and initiated a project aiming to dissect the unusual mechanisms of cell cycle control in this parasitic protozoan.
During 2003 to 2005, I worked as a research fellow at Temasek Life Sciences Laboratories in Singapore, and from 2005 to 2009 I was an assistant research scientist (assistant research professor) at UCSF. In 2009 I moved to the University of Texas-Houston Medical School to start my own laboratory. I am currently a faculty member of McGovern Medical School at Houston and UT Graduate school of Biomedical Sciences. I am also an adjunct faculty member at the National School of Tropical Medicine of Baylor College of Medicine.
- Postdoctoral Fellow
- University of California-San Francisco
- Institute of Genetics, Chinese Academy of Sciences
Cell cycle regulation in trypanosomes
My laboratory is mainly interested in understanding the molecular mechanism of mitosis and cytokinesis. We use Trypanosoma brucei, a unicellular eukaryote and the causative agent of human sleeping sickness, as a model organism to address the fundamental questions of how mitosis and cytokinesis are regulated and coordinated during cell division. The current focus is on the cell cycle regulatory pathways consisting of protein kinases such as Aurora B kinase, Polo-like kinase and Tousled-like kinase, spindle-associated motor proteins, and ubiquitin ligases.
We are also interested in the role of ubiquitin-dependent and -independent proteolysis in various cell biological processes. ATP-dependent protease complexes are present in all three kingdoms of life where they ride the cell of mis-folded or damaged proteins and control the level of certain regulatory proteins. These proteases include the 26S proteasome in eukaryotes, Archaea, and Actinomycetales and the HslVU protease in eubacteria. The current focus is on three proteolytic pathways: the Cullin-RING ubiquitin ligase (CRL) and the anaphase-promoting complex/cyclosome (APC/C) on cell cycle control and the HslVU protease on mitochondrial DNA replication.
We use a combination of genetics, biochemistry, cell biology, molecular biology, chemical genetics, and proteomics to elucidate the molecular and cellular basis of cell cycle control in trypanosomes. We hope to provide a few drug targets for anti-trypanosome chemotherapy.
Wei Y., Hu H., Lun Z.-R., and Li Z. (2014) Centrin3 in trypanosomes maintains the stability of a flagellar inner-arm dynein for cell motility. Nature Communications, 5: 4060
Zhou Q., Hu H., and Li Z. (2014) New insights into the molecular mechanisms of mitosis and cytokinesis in trypanosomes. International Review of Cell and Molecular Biology, 308: 127-166
Hu H., Yu Z., Liu Y., Wang T., Wei Y., and Li Z. (2014) The Aurora B kinase in Trypanosoma brucei undergoes post-translational modifications and is targeted to various subcellular locations through binding to TbCPC1. Molecular Microbiology, 91: 256-274
Wei Y., Hu H., and Li Z. (2014) Distinct roles of a mitogen-activated protein kinase in cytokinesis between different life cycle forms of Trypanosoma brucei. Eukaryotic Cell, 13: 110-118
Liu Y., Hu H., and Li Z. (2013) The cooperative roles of PHO80-like cyclins in regulating the G1/S transition and posterior cytoskeletal morphogenesis in Trypanosoma brucei. Molecular Microbiology, 90:130-146
Positions for postdoctoral fellow and rotation students are available. Please send your application to Dr. Li at Ziyin.Li@uth.tmc.edu