CHE 598 Seminar: Structural and Functional Study of the Mobil Domain of Cardiac Troponin I in Myofilament Regulation
About the event
SPEAKER: Dr. Wenji Dong, Paul Hohenschuh Distinguished Professor, WSU Voiland School of Chemical Engineering and Bioengineering
BIOGRAPHY:
Wenji Dong is a professor in Voiland School of Chemical Engineering and Bioengineering at Washington State University. Dr. Dong received his B.S./M.S. in chemistry from Lanzhou University, China, Ph.D. in biophysics from London University, England and completed his postdoc training in the fields of biophysics/spectroscopic in University of Western Ontario, Canada. Before he joined WSU at 2006, he was a Muscular Dystrophy Association (MDA) postdoctoral research fellow, American Heart Association (AHA) Young Scientist Research fellow and research assistant professor in University of Alabama at Birmingham. Dr. Dong’s current research interests focus on 1) structural and functional study to understand calcium-based and sarcomere length-based regulations of myofilament function; 2) develop protein-based and nucleic acid amplification based lateral flow assay (LFA) biosensing technology for rapid detections of infectious disease and cancer diagnostics, and 3) Explore bacterial extracellular vesicles as novel antibiotics against multi-drug resistant bacterial infections. More information about his overall research activities can be found at https://scholar.google.com/citations?hl=en&user=tUEtVzYAAAAJ.
ABSTRACT:
In cardiac muscle, myocardial activation is initiated when Ca²⁺ binds to cardiac troponin (cTn), a complex composed of troponin C (cTnC), troponin I (cTnI), and troponin T (cTnT). cTnC serves as the Ca²⁺ sensor and, together with cTnI, plays a central role in regulating contraction and relaxation. The regulatory function of cTnI resides in three contiguous regions within its C-terminal domain: the inhibitory region (IR), the regulatory region (RR), and the mobile domain (MD). The structural dynamics of these regions—and the kinetics of transitions between their dynamic states are thought to mediate regulatory signaling. Among them, the MD is particularly distinctive: it modulates Ca²⁺ sensitivity and force development through a Ca²⁺-dependent transition between ordered and intrinsically disordered conformations. In this talk, I will describe fluorescence spectroscopic approaches used in my lab to investigate probe structural dynamics and kinetics associated with functions of the MD of cTnI in both in-vitro and in-situ settings. I will present findings from our studies on structural dynamic features of the MD domain and how they influence myofilament Ca²⁺ sensitivity and activation-dependent force development. Finally, I will discuss the potential therapeutic implications of these results.