Tian Jin, Ph.D.
Chief, Chemotaxis Signal Section
Investigator
Dr. Jin received his B.S. in biology from the Beijing University, China, in 1984 and his Ph.D. degree from the Department of Biochemistry at the Robert Wood Johnson Medical School at Rutgers-UMDNJ in 1994. From 1994 to 2000, he was a postdoctoral fellow in the Department of Biological Chemistry at Johns Hopkins University School of Medicine. Dr. Jin was appointed instructor in the Department of Cell Biology and Anatomy at Johns Hopkins University School of Medicine in 2001. In July 2001, he joined the Laboratory of Immunogenetics as a tenure-track investigator.
Description of Research Program
The research in the Chemotaxis Signal Section is focused on understanding the cellular and molecular mechanisms underlying three interrelated processes, namely chemotaxis, phagocytosis, and the chemokine-receptor-mediated HIV infection of immune cells. Our research strategy to delineate the mechanisms underlying chemotaxis and phagocytosis relies on the use of the genetically amendable model organism, Dictyostelium discoideum.
The overall thrust of our research is to use cutting-edge live-cell imaging techniques, including FRET, FRAP and single molecule imaging, to reveal the dynamics of signaling molecules in space and time, and to construct computational models that faithfully simulate the experimental observations and offer testable predictions to refine our understanding of signaling networks at a system level. We also apply a combination of molecular, genetic, and biochemical approaches to elucidate molecular mechanisms underlying chemotaxis, phagocytosis, and chemokine-receptor-mediated entry of HIV. Definition of the molecular details of these processes will not only be essential for understanding these fundamental biological functions, but will also likely reveal novel targets for therapeutic development as well as biomarkers for monitoring the progression of immune disorders and response to therapeutic interventions.
Current Projects
- Determine the molecular mechanisms of a GPCR signaling network that mediates chemotaxis
- Reveal the molecular machinery controlling phagosome maturation in phagocytosis
- Analyze CD4 and CCR5 receptors at the single-molecule level during the formation of HIV entry complex
Research Group Members
Nilgun Isik, Ph.D., Janshe Yan, Ph.D., Tobias Meckel, Ph.D., Jiang Hong, Ph.D., Neela Satyanarayan, B.S., Michael Wu, B.S.
Selected Publications
(Search PubMed.)
Fang J, Brzostowski JA, Ou S, Isik N, Nair V, Jin T. A vesicle surface tyrosine kinase regulates phagosome maturation. J Cell Biol. 2007 Jul 30;178(3):411-23.
Xu X, Meier-Schellersheim M, Yan J, Jin T. Locally controlled inhibitory mechanisms are involved in eukaryotic GPCR-mediated chemosensing. J Cell Biol. 2007 Jul 2;178(1):141-53.
Meier-Schellersheim M, Xu X, Angermann B, Kunkel EJ, Jin T, Germain RN.Key role of local regulation in chemosensing revealed by a new molecularinteraction-based modeling method. PLoS Comput Biol. 2006 Jul 21;2(7):e82.
Jin T, Hereld D. Moving toward understanding eukaryotic chemotaxis. Eur J Cell Biol. 2006 Sep;85(9-10):905-13.
Yi L, Fang J, Isik N, Chim J, Jin T. HIV gp120-induced interaction between CD4 and CCR5 requires cholesterol-rich microenvironments revealed by live cell fluorescence resonance energy transfer imaging. J Biol Chem. 2006 Nov 17;281(46):35446-53.
Xu X, Meier-Schellersheim M, Jiao X, Nelson LE, Jin T. Quantitative imaging of single live cells reveals spatiotemporal dynamics of multistep signaling events of chemoattractant gradient sensing in Dictyostelium. Mol Biol Cell. 2005 Feb;16(2):676-88.
Jiao X, Zhang N, Xu X, Oppenheim JJ, Jin T. Ligand-induced partitioning of human CXCR1 chemokine receptors with lipid raft microenvironments facilitates G-protein-dependent signaling. Mol Cell Biol. 2005 Jul;25(13):5752-62.
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