G protein-coupled receptors (GPCRs) modulate essential processes in cardiovascular systems, including heart rate, blood pressure and contractility. Abnormal GPCR activity leads to pathological conditions, such as cardiac hypertrophy and heart failure. A critical regulatory step in GPCR signaling is the phosphorylation of active receptor by GPCR kinases (GRKs). GRKs selectively recognize and are allosterically regulated by activated GPCRs and the GRK-lipid interaction also promotes its kinase activity for GPCR, however the underlying molecular mechanisms are not understood. I have stabilized a physiological GRK1-rhodopsin complex with a chemical crosslinker and determined a negative stain EM model. I propose to use mass spectrometry to identify the reactive residues in GRK1 and rhodopsin. The distance restraints between crosslinked sites, along with negative staining model, will provide valuable structural insights of the GPCR and GRK1 interaction. I also propose to determine a high resolution cryo-electron microscope structure of the stabilized complex. The results will greatly advance our knowledge about how GRKs recognize the active conformation of GPCRs and how the activated receptor in turn activates GRKs, and thereby potentially reveal new ways to inhibit GRK activity in pathological settings.
|Program type||Postdoctoral Fellowship|
|Effective start/end date||01/01/2019 → 12/31/2020|