Dynamic allosteric networks drive adenosine A1 receptor activation and G-protein coupling

  1. Miguel A Maria-Solano  Is a corresponding author
  2. Sun Choi  Is a corresponding author
  1. Global AI Drug Discovery Center, College of Pharmacy and Graduate School of Pharmaceutical Science, Ewha Womans University, Republic of Korea
8 figures and 2 additional files

Figures

Figure 1 with 8 supplements
Free energy landscape (FEL) of A1R activation in the presence of adenosine (ADO).

(A) TM6 inward-to-outward conformational transition observed in the inactive (PDB 5N2S) and active (PDB 6D9H) X-Ray and Cryo-EM structures. (B) Features used to follow the TM6 inward-to-outward …

Figure 1—figure supplement 1
Representation of the A1R receptor in complex with heterotrimeric Gi2 protein (PDB 6D9H).

The helices and loops of the A1R receptor are depicted with different colors while the heterotrimeric Gi2 protein is in gray. The Gαi2-α5 helix that binds into the intracellular cavity of the …

Figure 1—figure supplement 2
Structures used as starting points for the walker metadynamics simulations.

(A) Population analysis of the A1R activation obtained from conventional molecular dynamics (cMD) simulations starting from the inactive X-Ray and active Cryo-EM structures, the coordinates of the …

Figure 1—figure supplement 3
Estimate of the free energy differences between the energy minima of the free energy surface.

The lines represent the mean ΔΔG value of the 10 walker replicas along the simulation time. The energy differences between the inactive-active, inactive-intermediate, and active-intermediate energy …

Figure 1—figure supplement 4
Evolution of the CV1 (TM3-TM6 Distance) over the simulation time.

(A) Plot showing that the multiple-walkers (W1-10) sampling covers the CV space. (B) For clarity, only two walkers (W1 and W2) are represented.

Figure 1—figure supplement 5
2D free energy landscape of A1R associated with the TM3-TM6 intracellular ends distance and its associated error.

The free energy landscape is represented by a gray line while its associated error corresponds to the yellow-shaded area. The error was estimated using the block averaging technique, as described in …

Figure 1—figure supplement 6
Representation of relevant micro-switches for A1R.

The inactive X-Ray (PDB 5N2S) and active Cryo-EM (PDB 6D9H) structures are displayed in blue and magenta, respectively. The metrics used in this work are highlighted in spheres for the psi dihedral …

Figure 1—figure supplement 7
Reweighting of the metadynamics simulations onto 2D free energy profiles.

The original biased collective variables (CVs) are shown in purple while the unbiased CVs (i.e. the micro-switches) are in blue. The inactive and active regions of the CV space are highlighted. Note …

Figure 1—figure supplement 8
Reweighting of the metadynamics simulations onto 3D free energy profiles.

The reweighting analysis shows that the activation energy barrier associated with the free energy landscape (FEL) of CV1 and the PIF motif is similar to that of the original biased FEL (i.e. CV1 and …

Figure 2 with 1 supplement
Protein energy networks (PEN) of A1R-ADO conformational ensemble.

The PEN identifies extra and intracellular communication centers together with the allosteric pathways that interconnect them. The PEN residues (nodes) are represented by colored spheres as a …

Figure 2—figure supplement 1
Adenosine interactions with protein energy networks (PEN) residues in the A1R-ADO conformational ensemble.

Representative structures from the broad range of conformations sampled by adenosine (ADO) in the metadynamics simulations are shown as gray sticks. The PEN residues (nodes) that perform transient …

Figure 3 with 2 supplements
Protein energy networks (PEN) of A1R-ADO in the inactive, intermediate, and pre-active states.

(A) The PEN residues (nodes) are represented by colored spheres as a function of the receptor region (e.g. TM6 nodes in teal) while the allosteric pathways (edges) as yellow-orange sticks. The size …

Figure 3—figure supplement 1
Representation of the free energy landscape (FEL) of A1R-ADO activation split into conformational states.

The inactive, intermediate, and pre-active regions of the FEL are separated by black dashed lines. The number of structures associated with each conformational state is also shown.

Figure 3—figure supplement 2
Illustration of the conformational dynamics of the micro-switches along A1R activation.

The histograms corresponding to the inactive, intermediate, and pre-active states are colored blue, green, and pink, respectively. The ionic-lock dynamics reveals that E229-R108 is the strongest …

Effect of G-protein binding on the conformational ensemble of A1R-ADO.

(A) Population analysis of A1R activation in the ADO-A1R-Gi2 complex obtained from conventional molecular dynamics (cMD) simulations. The TM6 torsion corresponds to the dihedral angle formed by the …

Effect of G-protein binding on A1R-ADO the protein energy networks (PEN) of A1R-ADO.

The PEN residues (nodes) are represented by colored spheres as a function of the receptor region (e.g. TM6 nodes in teal) while the allosteric pathways (edges) as yellow-orange sticks. The size of …

Energy coupling between the transient pockets formed along receptor activation.

(A) Iso-surface representation of the normalized frequency map (set at Φi=0.2 iso-value) obtained from MDPocked in the inactive (blue), intermediate (teal), pre-active (violet), and fully-active …

Figure 7 with 1 supplement
Energy coupling between pocket B and pocket D along receptor activation.

Zoom view of the transient pockets and protein energy networks of the upper region of the receptor. Adenosine (ADO) in pocket B and the MIPS521 positive allosteric modulator (PAM) in pocket D, both …

Figure 7—figure supplement 1
A1R shallow pocket of the MIPS521 positive allosteric modulator (PAM), PDB 7LD3.

The MIPS521 PAM is depicted in orange sticks while its interacting residues are colored as a function of the receptor region (e.g. TM6 nodes in teal). The experimentally identified allosteric …

Figure 8 with 1 supplement
Effect of adenosine (ADO) and MIPS51 positive allosteric modulator (PAM) binding on the protein energy networks (PEN) of A1R-Gi2.

ADO in pocket B and MIPS521 PAM in pocket D, both aligned from PDB 7LD3, are depicted in gray and orange sticks, respectively. Note that ADO and PAM sticks are displayed with transparency in the …

Figure 8—figure supplement 1
Effect of ADO and MIPS51 PAM on the conformational landscape of A1R in the presence of G-protein.

Population analysis of A1R activation in the A1R-Gi2 (left), ADO-A1R-Gi2 (middle), and PAM- ADO-A1R-Gi2 (right) complexes obtained from conventional molecular dynamics (cMD) simulations. The TM6 …

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