Dual Systems for Enhancing Control of Protein Activity through Induced Dimerization Approaches

Abstract

To reveal the underpinnings of complex biological systems, a variety of approaches have been developed that allow switchable control of protein function. One powerful approach for switchable control is the use of inducible dimerization systems, which can be configured to control activity of a target protein upon induced dimerization triggered by chemicals or light. Individually, many inducible dimerization systems suffer from pre‐defined dynamic ranges and overwhelming sensitivity to expression level and cellular context. Such systems often require extensive engineering efforts to overcome issues of background leakiness and restricted dynamic range. To address these limitations, recent tool development efforts have explored overlaying dimerizer systems with a second layer of regulation. Albeit more complex, the resulting layered systems have enhanced functionality, such as tighter control that can improve portability of these tools across platforms.

Exploring the memory: existing activity-dependent tools to tag and manipulate engram cells

“…Single-component fluorescent calcium integrators have emerged as a powerful tool to map activated neural circuits due to their faster response to neural activity compared to the IEG-based systems that are limited by drug delivery and metabolic speed in the brain (Greenwald et al, 2018 ; Losi et al, 2018 ; Luo et al, 2018 ; Mena et al, 2018 ; Robinson and Gradinaru, 2018 ; Wang et al, 2018 ; Lin et al, 2019 ; Abreu and Levitz, 2020 ; Chung and Lin, 2020 ; Labouesse et al, 2020 ; Covey and Yocky, 2021 ; Pearce and Tucker, 2021 ; Gao et al, 2022 ; Manhas et al, 2022 ; Shen et al, 2022 ; Wu et al, 2022 ). These integrators comprise photoconvertible or photoswitchable proteins, also called genetically encoded calcium indicators (GECIs; Mank and Griesbeck, 2008 ; Grienberger and Konnerth, 2012 ; Looger and Griesbeck, 2012 ; Kaestner et al, 2014 ; Gibhardt et al, 2016 ; Lin and Schnitzer, 2016 ; Suzuki et al, 2016 ; Zhong and Schleifenbaum, 2019 ; Broussard and Petreanu, 2021 ; Inoue, 2021 ), which bind to calcium and undergo a rapid switch following exposure to light.…”