Optogenetic activation of heterotrimeric Gi proteins by LOV2GIVe— a rationally engineered modular protein

Heterotrimeric G-proteins are signal transducers that mediate the action of many natural extracellular stimuli as well as of many therapeutic agents. Non-invasive approaches to manipulate the activity of G-proteins with high precision are crucial to understand their regulation in space and time. Here, we engineered LOV2GIVe, a modular protein that allows the activation of Gi proteins with blue light. This optogenetic construct relies on a versatile design that differs from tools previously developed for similar purposes, i.e. metazoan opsins, which are light-activated GPCRs. To make LOV2GIVe, we fused a peptide derived from a non-GPCR protein that activates Gαi (but not Gαs, Gαq, or Gα12) to a small plant protein domain, such that light uncages the G-protein activating module. Targeting LOV2GIVe to cell membranes allowed for light-dependent activation of Gi proteins in different experimental systems. In summary, LOV2GIVe expands the armamentarium and versatility of tools available to manipulate heterotrimeric G-protein activity.