Source 1primary paper2008Brain Cell Biology
Toolkit/eNpHR
eNpHR
Also known as: enhanced NpHR
Taxonomy: Mechanism Branch / Architecture. Workflows sit above the mechanism and technique branches rather than replacing them.
Summary
The paper title explicitly names "eNpHR" and the web research summary states that the paper engineers NpHR to reduce ER retention/aggregation by adding an N-terminal signal peptide and a C-terminal ER export sequence, yielding enhanced NpHR (eNpHR) with improved membrane localization and larger photocurrents.
Usefulness & Problems
Why this is useful
eNpHR is described as a light-sensitive chloride pump that mediates light-activated hyperpolarization. The review presents it as an alternative optogenetic actuator for retinal photosensitization.; light-activated hyperpolarization of expressing cells; restoring light sensitivity to degenerated retina; eNpHR is an enhanced Natronomonas halorhodopsin variant engineered for optogenetic applications. The summary states that it improves membrane localization and produces larger photocurrents relative to the parent NpHR.; optogenetic applications; improved membrane localization of halorhodopsin-based optogenetic inhibitors; larger photocurrents than the parent NpHR construct
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eNpHR is described as a light-sensitive chloride pump that mediates light-activated hyperpolarization. The review presents it as an alternative optogenetic actuator for retinal photosensitization.
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light-activated hyperpolarization of expressing cells
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restoring light sensitivity to degenerated retina
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eNpHR is an enhanced Natronomonas halorhodopsin variant engineered for optogenetic applications. The summary states that it improves membrane localization and produces larger photocurrents relative to the parent NpHR.
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optogenetic applications
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improved membrane localization of halorhodopsin-based optogenetic inhibitors
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larger photocurrents than the parent NpHR construct
Problem solved
It can render inactive photoreceptors or other intact retinal cells responsive to light in degenerating retina.; confers photosensitivity to cells through light-driven hyperpolarization; supports mutation-agnostic retinal vision restoration strategies; The engineering addresses ER retention and aggregation of NpHR, which limited effective membrane localization. By improving trafficking, the construct is intended to perform better as an optogenetic tool.; ER retention and aggregation of NpHR; poor membrane localization of the parent NpHR construct
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It can render inactive photoreceptors or other intact retinal cells responsive to light in degenerating retina.
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confers photosensitivity to cells through light-driven hyperpolarization
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supports mutation-agnostic retinal vision restoration strategies
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The engineering addresses ER retention and aggregation of NpHR, which limited effective membrane localization. By improving trafficking, the construct is intended to perform better as an optogenetic tool.
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ER retention and aggregation of NpHR
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poor membrane localization of the parent NpHR construct
Problem links
confers photosensitivity to cells through light-driven hyperpolarization
LiteratureIt can render inactive photoreceptors or other intact retinal cells responsive to light in degenerating retina.
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It can render inactive photoreceptors or other intact retinal cells responsive to light in degenerating retina.
ER retention and aggregation of NpHR
LiteratureThe engineering addresses ER retention and aggregation of NpHR, which limited effective membrane localization. By improving trafficking, the construct is intended to perform better as an optogenetic tool.
Source:
The engineering addresses ER retention and aggregation of NpHR, which limited effective membrane localization. By improving trafficking, the construct is intended to perform better as an optogenetic tool.
poor membrane localization of the parent NpHR construct
LiteratureThe engineering addresses ER retention and aggregation of NpHR, which limited effective membrane localization. By improving trafficking, the construct is intended to perform better as an optogenetic tool.
Source:
The engineering addresses ER retention and aggregation of NpHR, which limited effective membrane localization. By improving trafficking, the construct is intended to perform better as an optogenetic tool.
supports mutation-agnostic retinal vision restoration strategies
LiteratureIt can render inactive photoreceptors or other intact retinal cells responsive to light in degenerating retina.
Source:
It can render inactive photoreceptors or other intact retinal cells responsive to light in degenerating retina.
Published Workflows
Objective: Engineer a Natronomonas halorhodopsin variant with reduced ER retention and aggregation for improved optogenetic use.
Why it works: The source summary states that adding an N-terminal signal peptide and a C-terminal ER export sequence to NpHR reduces ER retention and aggregation, which is expected to improve membrane localization and thereby increase photocurrents for optogenetic applications.
protein trafficking improvementER export enhancementconstruct engineering
Stages
- 1.Construct engineering of NpHR trafficking-enhanced variant(library_design)
This stage exists to redesign the parent NpHR construct so that trafficking defects are reduced before functional optogenetic use.
Selection: Addition of an N-terminal signal peptide and a C-terminal ER export sequence to address ER retention and aggregation.
- 2.Functional characterization of engineered construct(functional_characterization)
This stage exists to determine whether the trafficking-enhanced construct actually improves the properties needed for optogenetic applications.
Selection: Assessment of membrane localization and photocurrent improvement relative to parent NpHR.
Steps
- 1.Add N-terminal signal peptide to NpHRparent construct being engineered
Reduce trafficking-related limitations in the parent halorhodopsin construct.
The source summary presents construct modification as the first intervention used to address ER retention and aggregation before evaluating function.
- 2.Add C-terminal ER export sequence to create eNpHRengineered construct output
Further reduce ER retention and aggregation and produce the enhanced eNpHR construct.
The source summary describes the ER export addition as part of the engineering changes that yield eNpHR before functional evaluation.
- 3.Evaluate membrane localization and photocurrents relative to NpHRengineered construct and parent comparator
Test whether the engineered trafficking changes improve optogenetically relevant performance.
Functional evaluation follows construct engineering because the paper's goal is to determine whether the modifications improve localization and photocurrent output.
Taxonomy & Function
Primary hierarchy
Mechanism Branch
Architecture: A reusable architecture pattern for arranging parts into an engineered system.
Mechanisms
light-activated hyperpolarisationlight-driven chloride pumpingtrafficking enhancement via er export and reduced er retention/aggregationTechniques
No technique tags yet.
Target processes
localizationrecombinationInput: Light
Implementation Constraints
cofactor dependency: requires exogenous cofactorencoding mode: genetically encodedimplementation constraint: context specific validationimplementation constraint: spectral hardware requirementoperating role: regulator
It requires ectopic expression in retinal cells and light stimulation.; requires genetic modification to express the light-sensitive protein; requires light exposure; The construct requires the NpHR backbone plus an added N-terminal signal peptide and a C-terminal ER export sequence. Use is framed in the source as an optogenetic application, implying light-based deployment.; requires addition of an N-terminal signal peptide; requires addition of a C-terminal ER export sequence
The abstract does not specify which retinal cell targets, delivery systems, or visual performance limits apply to eNpHR-based restoration.
Validation
Cell-freeBacteriaMammalianMouseHumanTherapeuticIndep. Replication
Supporting Sources
Ranked Claims
The paper engineers NpHR by adding an N-terminal signal peptide and a C-terminal ER export sequence to create eNpHR.
The paper engineers NpHR to reduce ER retention/aggregation by adding an N-terminal signal peptide and a C-terminal ER export sequence, yielding enhanced NpHR (eNpHR).
eNpHR is an enhanced Natronomonas halorhodopsin engineered for optogenetic applications.
eNpHR: a Natronomonas halorhodopsin enhanced for optogenetic applications
eNpHR has improved membrane localization and larger photocurrents relative to the parent NpHR construct.
yielding enhanced NpHR (eNpHR) with improved membrane localization and larger photocurrents
Approval Evidence
2 sources6 linked approval claimsfirst-pass slug enphr
Along with other light-sensitive proteins such as the chloride pump eNpHR, which mediates light-activated hyperpolarisation... The ectopic expression of channelrhodopsin or eNpHR may cause inactive photoreceptors or other, intact cells of the retina to become sensitive to light.
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The paper title explicitly names "eNpHR" and the web research summary states that the paper engineers NpHR to reduce ER retention/aggregation by adding an N-terminal signal peptide and a C-terminal ER export sequence, yielding enhanced NpHR (eNpHR) with improved membrane localization and larger photocurrents.
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application scopesupports
Optogenetic tools are well suited to treat retinas with photoreceptor degeneration independently of the underlying mutation.
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mechanismsupports
eNpHR is a chloride pump that mediates light-activated hyperpolarization.
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therapeutic rationalesupports
Ectopic expression of channelrhodopsin or eNpHR can make inactive photoreceptors or other intact retinal cells sensitive to light, thereby restoring the basic retinal function of light perception.
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design modificationsupports
The paper engineers NpHR by adding an N-terminal signal peptide and a C-terminal ER export sequence to create eNpHR.
The paper engineers NpHR to reduce ER retention/aggregation by adding an N-terminal signal peptide and a C-terminal ER export sequence, yielding enhanced NpHR (eNpHR).
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engineering outcomesupports
eNpHR is an enhanced Natronomonas halorhodopsin engineered for optogenetic applications.
eNpHR: a Natronomonas halorhodopsin enhanced for optogenetic applications
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performance improvementsupports
eNpHR has improved membrane localization and larger photocurrents relative to the parent NpHR construct.
yielding enhanced NpHR (eNpHR) with improved membrane localization and larger photocurrents
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Comparisons
Source-stated alternatives
The abstract directly contrasts eNpHR with channelrhodopsin and mentions other light-sensitive proteins acting through ion flow or secondary signaling cascades.; The source context names the parent NpHR as the baseline comparator. ChR2 and VChR1 are mentioned in the research summary as nearby optogenetic tools discussed in the same framework, but not as direct substitutes for the same inhibitory function.
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The abstract directly contrasts eNpHR with channelrhodopsin and mentions other light-sensitive proteins acting through ion flow or secondary signaling cascades.
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The source context names the parent NpHR as the baseline comparator. ChR2 and VChR1 are mentioned in the research summary as nearby optogenetic tools discussed in the same framework, but not as direct substitutes for the same inhibitory function.
Source-backed strengths
part of a broad optogenetic toolset for non-invasive single-cell manipulation; improved membrane localization; larger photocurrents; engineered specifically for optogenetic use
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part of a broad optogenetic toolset for non-invasive single-cell manipulation
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improved membrane localization
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larger photocurrents
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engineered specifically for optogenetic use
Compared with opsins
The abstract directly contrasts eNpHR with channelrhodopsin and mentions other light-sensitive proteins acting through ion flow or secondary signaling cascades.
Shared frame: source-stated alternative in extracted literature
Strengths here: part of a broad optogenetic toolset for non-invasive single-cell manipulation; improved membrane localization; larger photocurrents.
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The abstract directly contrasts eNpHR with channelrhodopsin and mentions other light-sensitive proteins acting through ion flow or secondary signaling cascades.
Compared with optogenetic
The source context names the parent NpHR as the baseline comparator. ChR2 and VChR1 are mentioned in the research summary as nearby optogenetic tools discussed in the same framework, but not as direct substitutes for the same inhibitory function.
Shared frame: source-stated alternative in extracted literature
Strengths here: part of a broad optogenetic toolset for non-invasive single-cell manipulation; improved membrane localization; larger photocurrents.
Source:
The source context names the parent NpHR as the baseline comparator. ChR2 and VChR1 are mentioned in the research summary as nearby optogenetic tools discussed in the same framework, but not as direct substitutes for the same inhibitory function.
Ranked Citations
- 1.