FIGURE 5.

The architecture of transmembrane AMPAR regulatory proteins (TARPs) and tetraspanins (TSPANs). (A) Overall topology of TARPs (left) in comparison to tetraspanins (right). (B) Ribbon diagrams, rainbow-colored (from N-terminus in blue to C-terminus in red), representing the structures of TARPs (left) based on the structure of human TARP γ2, originally named stargazin and resolved by cryo-EM (pdb model 6DLZ, published by Twomey et al., 2018), and human Tspan25 (right), also known as CD53, resolved by crystallization and X-ray diffraction (pdb model 6WVG, published by Yang et al., 2020). Cysteine residues and disulfide bridges are presented as yellow heteroatoms and sticks, respectively. Distinct domains are labeled. Black boxes indicate the areas of TARPs and tetraspanins enlarged in panel (C). Cysteine residues forming disulfide bridges in the big loops are labeled (one-letter amino acid code with number of each residue) and presented in ball and stick style with sulfur and carbon shown in yellow and gray, respectively.