2019 AMI Online Salon

Rhodopsin Phosphorylation and Arrestin Activation

Project Details

  • Entrant Name: Brianna Monroe

  • Membership Type: Student Submission

  • Other Contributors: EvelynMaizels,IsabelRomero                     

  • Address: Chicago,IL

  • Client: University of Illinois at Chicago

  • Medium/software used: VMD, Autodesk 3dsMax and Adobe Photoshop. Structural data for the arrestin-rhodopsin complex obtained from Protein Databank (PDB file 5WOP; Zhou et al., Cell 170:457-469, 2017). Distribution of electrostatic charge visualized using Adaptive Poisson-Boltz

  • Final presentation format: Printed poster 18”x24”

  • Primary Audience: Academic, with knowledge of GPCRs and phosphorylation.

Project Description

Rhodopsin, the light-sensitive receptor pigment activated by photons within rod cells of the retina, is a class A GPCR which binds and activates arrestin. Phosphorylation of key residues within rhodopsin introduce a new negative charge density within the C-terminal tail of rhodopsin, permitting docking of arrestin to rhodopsin and activation of the bound arrestin. The negatively-charged phosphorylated rhodopsin residues, PT336 and PS338, can undergo charge-based interactions with a set of positively charged arginine and lysine residues that form arrestin’s phosphate binding pocket. Lower middle inset shows the distribution of electrostatic charge across arrestin’s surface as an electrostatic surface potential, by the blue surface indicating a strong positive charge in the phosphate binding pocket. Phosphorylation of the C-terminal tail residues disrupts the positive and negative charges of the finger loop lock of arrestin, causing the finger loop to unlock and arrestin to be activated.