Engineering Photosensory Modules of Non-Opsin-Based Optogenetic Actuators

Abstract

Optogenetic (photo-responsive) actuators engineered from photoreceptors are widely used in various applications to study cell biology and tissue physiology. In the toolkit of optogenetic actuators, the key building blocks are genetically encodable light-sensitive proteins. Currently, most optogenetic photosensory modules are engineered from naturally-occurring photoreceptor proteins from bacteria, fungi, and plants. There is a growing demand for novel photosensory domains with improved optical properties and light-induced responses to satisfy the needs of a wider variety of studies in biological sciences. In this review, we focus on progress towards engineering of non-opsin-based photosensory domains, and their representative applications in cell biology and physiology. We summarize current knowledge of engineering of light-sensitive proteins including light-oxygen-voltage-sensing domain (LOV), cryptochrome (CRY2), phytochrome (PhyB and BphP), and fluorescent protein (FP)-based photosensitive domains (Dronpa and PhoCl).

Advanced Optogenetic-Based Biosensing and Related Biomaterials

“…Importantly, the available repertoire of optogenetic systems based on genetically encoded light-sensitive proteins is more vast, comprising not only bacterial [ 23 ] and animal opsins [ 36 ] but also non-opsin-based optogenetic actuators [ 66 ]. The later include light-oxygen-voltage-sensing domain (LOV) [ 67 ], cryptochrome (CRY2), phytochrome (PhyB and BphP) and fluorescent protein (FP)-based photosensitive domains (Dronpa and PhoCl) [ 66 ].…”

Deciphering Molecular Mechanisms and Intervening in Physiological and Pathophysiological Processes of Ca2+ Signaling Mechanisms Using Optogenetic Tools

“…These can be classified according to their function, distinguishing between photosensitive proteins that oligomerize or undergo a structural change upon irradiation with light. Their common feature is the binding of a chromophore as a cofactor for photosensitivity [ 220 ].…”

“…While these photosensory domains have been described in detail elsewhere [ 220 , 239 ], in the following, we focus on their application in the Ca 2+ signaling field, where they have recently been used to transfer light-sensitivity to "blind" Ca 2+ signaling proteins ( Table 3 ). In addition, we discuss their utility to date, as well as some open questions for gaining new mechanistic insights into protein function.…”

Photocleavable proteins that undergo fast and efficient dissociation

“…As a burgeoning range of biological techniques, optogenetics, which involves the use of light and genetically encodable lightsensitive proteins, enables unprecedented levels of control of numerous biological processes ranging from cellular activities to animal behaviours [1][2][3] . Genetically encodable light-sensitive proteins, as a key component of optogenetic actuators, are typically engineered from natural photoreceptors 4 . The current repertoire of engineered optogenetic actuators can be divided into the following categories 4,5 : (i) opsin-based lightactivatable channels or pumps (e.g., ChR2 [ref.…”

“…Genetically encodable light-sensitive proteins, as a key component of optogenetic actuators, are typically engineered from natural photoreceptors 4 . The current repertoire of engineered optogenetic actuators can be divided into the following categories 4,5 : (i) opsin-based lightactivatable channels or pumps (e.g., ChR2 [ref. 6], eNpHR 7 , eBR 8 and OptoXR 9 ); (ii) proteins with light-induced allosteric change (e.g., LINuS 10 , LEXY 11 and PA-Rac1 [ref.…”