Dissociation of Heterotrimeric G Proteins in Cells (Interactive Figures)

Nevin A. Lambert¹*

¹ Department of Pharmacology and Toxicology, Medical College of Georgia, Augusta, GA 30912–2300, USA

*Corresponding author. E-mail: nlambert{at}mcg.edu

Interactive Image 1. A heterotrimeric G protein based on PDB entry 1GP2 and visualized with JMOL (1). This is an interactive spacefill rendering of Gαi1 and Gβ1γ2.

Interactive Image 2. The image shows a surface rendering of Gαi1 with the contact residues in the αN helix colored yellow and in the switch region colored blue where the α subunit contacts the βγ subunit. The blue residues here on Gαi1 contact blue residues on Gβ1γ2 and yellow residues on Gαi1 contact yellow residues on Gβ1γ2. (Gβγ is shown in Interactive Image 3.) This image is based on the same PDB file as that shown in Interactive Image 1; only the α subunit is displayed. This image provides an interactive version of the left model shown in Fig. 2, which is also displayed as a static image here.

Interactive Image 3. The image shows a surface rendering of Gβ1γ2 with the contact residues in the αN helix colored yellow and in the switch region colored blue where the α subunit contacts the βγ subunit. The blue residues here on Gβ1γ2 contact blue residues on Gαi1 and yellow residues on Gβ1γ2 contact yellow residues on αi1. (Gαi1 is shown in the Interactive Image 2.) This image is based on the same PDB file as that shown in Interactive Image 1; only the βγ subunits are displayed. This image provides an interactive version of the middle model shown in Fig. 2, which is also displayed as a static image here.

Interactive Image 4. The image shows a surface rendering of Gβ1γ2 with the contact residues involved in the interaction between G protein-coupled receptor kinase 2 (GRK2) and the α subunit colored. Surface residues that contact only GRK2 are shown in red, those that contact both GRK2 and the αN helix of Gαi1 are shown in orange, and those that contact both GRK2 and the switch regions of Gαi1 are shown in purple. GRK2 and Gαi1 bind to overlapping residues in both interfaces; thus, it is unlikely that Gβ1γ2 interacts with GRK2 and Gα simultaneously. This image is based on the same PDB file as that shown in Interactive Image 1; only the βγ subunits are displayed. This image provides an interactive version of the right model shown in Fig. 2, which is also displayed as a static image here.

Tips for using the JMOL applet (1). To move the image, click in the image and hold the mouse button down and move the mouse. To zoom in or out, click in the image and hold down the mouse button with the "Shift" key depressed. In Windows, right-clicking anywhere on the JMOL image, or using either mouse button to click on the "JMOL" in the lower right corner will generate a pop-up menu that provides many options for changing the view. To restore the original view, reload the page in the browser. Please note that you may need to move the JMOL interactive versions of the images to orient them the same as the static images.

Reference

Citation: N. A. Lambert, Dissociation of Heterotrimeric G Proteins in Cells. Sci. Signal. 1, re5 (2008).