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Investigating neuronal function with optically controllable proteins.

Zhou XX, Pan M, Lin MZ - Front Mol Neurosci (2015)

Bottom Line: For example, neurite extension and synaptogenesis both involve localized and transient activation of cytoskeletal and signaling proteins, allowing changes in microarchitecture to occur rapidly and in a localized manner.These tools have demonstrated versatility in controlling various proteins and thereby cellular functions, and possess enormous potential for future applications in nervous systems.Just as optogenetic control of neuronal firing using opsins has changed how we investigate the function of cellular circuits in vivo, optical control may yet yield another revolution in how we study the circuitry of intracellular signaling in the brain.

View Article: PubMed Central - PubMed

Affiliation: Department of Bioengineering, Stanford University Stanford, CA, USA.

ABSTRACT
In the nervous system, protein activities are highly regulated in space and time. This regulation allows for fine modulation of neuronal structure and function during development and adaptive responses. For example, neurite extension and synaptogenesis both involve localized and transient activation of cytoskeletal and signaling proteins, allowing changes in microarchitecture to occur rapidly and in a localized manner. To investigate the role of specific protein regulation events in these processes, methods to optically control the activity of specific proteins have been developed. In this review, we focus on how photosensory domains enable optical control over protein activity and have been used in neuroscience applications. These tools have demonstrated versatility in controlling various proteins and thereby cellular functions, and possess enormous potential for future applications in nervous systems. Just as optogenetic control of neuronal firing using opsins has changed how we investigate the function of cellular circuits in vivo, optical control may yet yield another revolution in how we study the circuitry of intracellular signaling in the brain.

No MeSH data available.


Recent uses of LOV and CRY2 domains with potential neuroscience applications. (A) Motor protein direction can be modified by changing the lever arm length using a LOV2 domain. An artificial lever arm was made by fusing two α-actinin structural elements (arm and extension) to LOV2, then this was attached to a motor protein’s catalytic domain (motor body). Change in lever arm geometry upon illumination resulted in a change in motor direction. (B) Light-induced LOV2 conformational change was also used to disrupt the folding of two fragments of calmodulin, allowing light-induced release of calcium. (C) The LARIAT method enables temporary inactivation of a POI by sequestration. LARIAT consists of CRY2 conjugated to a POI or an antibody fragment recognizing the POI (Ab) and CIB1 conjugated to a multimerizing protein (M). Blue light excitation causes the POI to aggregate to the multimer clusters formed by the CIB1-M construct.
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Figure 6: Recent uses of LOV and CRY2 domains with potential neuroscience applications. (A) Motor protein direction can be modified by changing the lever arm length using a LOV2 domain. An artificial lever arm was made by fusing two α-actinin structural elements (arm and extension) to LOV2, then this was attached to a motor protein’s catalytic domain (motor body). Change in lever arm geometry upon illumination resulted in a change in motor direction. (B) Light-induced LOV2 conformational change was also used to disrupt the folding of two fragments of calmodulin, allowing light-induced release of calcium. (C) The LARIAT method enables temporary inactivation of a POI by sequestration. LARIAT consists of CRY2 conjugated to a POI or an antibody fragment recognizing the POI (Ab) and CIB1 conjugated to a multimerizing protein (M). Blue light excitation causes the POI to aggregate to the multimer clusters formed by the CIB1-M construct.

Mentions: In a unique use of the LOV2 domain, Nakamura et al. (2014) used the light-regulatable hinge nature of LOV2 to construct cytoskeletal motor proteins that speed up, slow down, or change trafficking direction in response to blue light (Figure 6A). Cytoskeletal motor proteins consist of a catalytic domain that hydrolyzes ATP to move along a component of the cytoskeleton (e.g., myosin moves along microfilaments and kinesin moves along microtubules) and a lever arm domain that connects the catalytic domain to the motor protein’s cargo. The difference between the center of mass of the lever arm before and after the powerstroke influences the direction and speed of the motor. Nakamura et al. (2014) constructed an artificial lever arm consisting of the LOV2 domain flanked by α-actinin structural elements, and attached this lever arm to a myosin catalytic domain. The LOV2 domain acts as a light-actuated hinge; the light-induced loosening of the LOV2 domain changes the exit angle of the distal part of the lever arm and thus the center of mass of the lever arm. Nakamura et al. (2014) found that this artificial lever arm was modular and could introduce light-dependent speed/direction control into a variety of motor proteins, including myosin and kinesin. Such optogenetic control of a cell’s organelle trafficking activities could be useful for study of neurons, in which cytoskeleton-directed organelle trafficking is required for neurite extension and synaptic maintenance and plasticity.


Investigating neuronal function with optically controllable proteins.

Zhou XX, Pan M, Lin MZ - Front Mol Neurosci (2015)

Recent uses of LOV and CRY2 domains with potential neuroscience applications. (A) Motor protein direction can be modified by changing the lever arm length using a LOV2 domain. An artificial lever arm was made by fusing two α-actinin structural elements (arm and extension) to LOV2, then this was attached to a motor protein’s catalytic domain (motor body). Change in lever arm geometry upon illumination resulted in a change in motor direction. (B) Light-induced LOV2 conformational change was also used to disrupt the folding of two fragments of calmodulin, allowing light-induced release of calcium. (C) The LARIAT method enables temporary inactivation of a POI by sequestration. LARIAT consists of CRY2 conjugated to a POI or an antibody fragment recognizing the POI (Ab) and CIB1 conjugated to a multimerizing protein (M). Blue light excitation causes the POI to aggregate to the multimer clusters formed by the CIB1-M construct.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4508517&req=5

Figure 6: Recent uses of LOV and CRY2 domains with potential neuroscience applications. (A) Motor protein direction can be modified by changing the lever arm length using a LOV2 domain. An artificial lever arm was made by fusing two α-actinin structural elements (arm and extension) to LOV2, then this was attached to a motor protein’s catalytic domain (motor body). Change in lever arm geometry upon illumination resulted in a change in motor direction. (B) Light-induced LOV2 conformational change was also used to disrupt the folding of two fragments of calmodulin, allowing light-induced release of calcium. (C) The LARIAT method enables temporary inactivation of a POI by sequestration. LARIAT consists of CRY2 conjugated to a POI or an antibody fragment recognizing the POI (Ab) and CIB1 conjugated to a multimerizing protein (M). Blue light excitation causes the POI to aggregate to the multimer clusters formed by the CIB1-M construct.
Mentions: In a unique use of the LOV2 domain, Nakamura et al. (2014) used the light-regulatable hinge nature of LOV2 to construct cytoskeletal motor proteins that speed up, slow down, or change trafficking direction in response to blue light (Figure 6A). Cytoskeletal motor proteins consist of a catalytic domain that hydrolyzes ATP to move along a component of the cytoskeleton (e.g., myosin moves along microfilaments and kinesin moves along microtubules) and a lever arm domain that connects the catalytic domain to the motor protein’s cargo. The difference between the center of mass of the lever arm before and after the powerstroke influences the direction and speed of the motor. Nakamura et al. (2014) constructed an artificial lever arm consisting of the LOV2 domain flanked by α-actinin structural elements, and attached this lever arm to a myosin catalytic domain. The LOV2 domain acts as a light-actuated hinge; the light-induced loosening of the LOV2 domain changes the exit angle of the distal part of the lever arm and thus the center of mass of the lever arm. Nakamura et al. (2014) found that this artificial lever arm was modular and could introduce light-dependent speed/direction control into a variety of motor proteins, including myosin and kinesin. Such optogenetic control of a cell’s organelle trafficking activities could be useful for study of neurons, in which cytoskeleton-directed organelle trafficking is required for neurite extension and synaptic maintenance and plasticity.

Bottom Line: For example, neurite extension and synaptogenesis both involve localized and transient activation of cytoskeletal and signaling proteins, allowing changes in microarchitecture to occur rapidly and in a localized manner.These tools have demonstrated versatility in controlling various proteins and thereby cellular functions, and possess enormous potential for future applications in nervous systems.Just as optogenetic control of neuronal firing using opsins has changed how we investigate the function of cellular circuits in vivo, optical control may yet yield another revolution in how we study the circuitry of intracellular signaling in the brain.

View Article: PubMed Central - PubMed

Affiliation: Department of Bioengineering, Stanford University Stanford, CA, USA.

ABSTRACT
In the nervous system, protein activities are highly regulated in space and time. This regulation allows for fine modulation of neuronal structure and function during development and adaptive responses. For example, neurite extension and synaptogenesis both involve localized and transient activation of cytoskeletal and signaling proteins, allowing changes in microarchitecture to occur rapidly and in a localized manner. To investigate the role of specific protein regulation events in these processes, methods to optically control the activity of specific proteins have been developed. In this review, we focus on how photosensory domains enable optical control over protein activity and have been used in neuroscience applications. These tools have demonstrated versatility in controlling various proteins and thereby cellular functions, and possess enormous potential for future applications in nervous systems. Just as optogenetic control of neuronal firing using opsins has changed how we investigate the function of cellular circuits in vivo, optical control may yet yield another revolution in how we study the circuitry of intracellular signaling in the brain.

No MeSH data available.