Unveiling Mechanical Activation: GAIN Domain Unfolding and Dissociation in Adhesion GPCRs

Abstract

Adhesion G protein-coupled receptors (aGPCRs) have extracellular regions (ECRs) containing GPCR autoproteolysis-inducing (GAIN) domains. The GAIN domain enables the ECR to self-cleave into N- and C-terminal fragments. However, the impact of force on the GAIN domain’s conformation, critical for mechanosensitive aGPCR activation, remains unclear. Our study investigated the mechanical stability of GAIN domains in three aGPCRs (B, G, and L subfamilies) at a loading rate of 1 pN/s. We discovered that forces of a few piconewtons can destabilize the GAIN domains. In autocleaved aGPCRs ADGRG1/GPR56 and ADGRL1/LPHN1, these forces cause the GAIN domain detachment from the membrane-proximal Stachel sequence, preceded by partial unfolding. In noncleavable aGPCR ADGRB3/BAI3 and cleavage-deficient mutant ADGRG1/GPR56-T383G, complex mechanical unfolding of the GAIN domain occurs. Additionally, GAIN domain detachment happens during cell migration. Our findings support the mechanical activation hypothesis of aGPCRs, emphasizing the sensitivity of the GAIN domain structure and detachment to physiological force ranges.

Unraveling the Dual-Stretch-Mode Impact on Tension Gauge Tethers’ Mechanical Stability

“…This characteristic holds promise for a variety of applications. In addition to shedding light on the time scales involved in specific mechanotransduction processes at cell–matrix adhesions, − cell–cell adherence junctions, and mechanical activation of T-cells, , they may also be applied to study the tension duration of various mechanically sensitive membrane receptors, such as adhesion GPCRs , and tethered ion channels . Moreover, the potential of dual-stretch-mode TGTs to significantly augment the utility of TGTs as mechanical instruments in DNA nanotechnology and bioengineering is considerable.…”

Structure of the extracellular region of the adhesion GPCR CELSR1 reveals a compact module which regulates G protein-coupling

“…71,85,86 The intricate, modular architectures of aGPCRs likely evolved to withstand and react to strict spatial and force requirements in order to mediate intracellular events. 3,7,[87][88][89][90][91] More experimental structures of aGPCRs with larger extracellular regions, such as ADGRV1 or ADGRG4, as well as comprehensive mechanistic studies including structural biology, adhesion, and signaling activities, will determine whether the CMM is a general structural feature of adhesion GPCRs.…”

Magnetogenetics as a promising tool for controlling cellular signaling pathways

“…Building upon the basis of magnetogenetics, the use of magnetic tweezers and beads has played a crucial role in proving that mechanical forces can trigger the separation of the GAIN domain within adhesive GPCRs, paving the way for novel techniques to regulate cellular functions [ 252 , 253 ]. This revelation is particularly significant as it highlights how mechanical forces can influence receptors previously considered insensitive to such stimuli.…”