Source 1primary paper2025MED
Toolkit/KnChR
KnChR
Also known as: Klebsormidium nitens channelrhodopsin
Taxonomy: Mechanism Branch / Architecture. Workflows sit above the mechanism and technique branches rather than replacing them.
Summary
Here we report the 2.7 Å-resolution cryo-electron microscopy structure of a ChR from Klebsormidium nitens (KnChR), which is one of the most blue-shifted ChRs.
Usefulness & Problems
Why this is useful
KnChR is a light-gated ion channel from Klebsormidium nitens presented here as a blue-shifted optogenetic actuator. The abstract states that UV or deep-blue light can activate KnChR-transfected precultured neurons.; optogenetic activation; multicolor optogenetics
Source:
KnChR is a light-gated ion channel from Klebsormidium nitens presented here as a blue-shifted optogenetic actuator. The abstract states that UV or deep-blue light can activate KnChR-transfected precultured neurons.
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optogenetic activation
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multicolor optogenetics
Problem solved
It addresses the need for channelrhodopsins with more distant absorption wavelengths for multicolor optogenetics.; provides a blue-shifted channelrhodopsin for spectral separation in multicolor optogenetics
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It addresses the need for channelrhodopsins with more distant absorption wavelengths for multicolor optogenetics.
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provides a blue-shifted channelrhodopsin for spectral separation in multicolor optogenetics
Problem links
provides a blue-shifted channelrhodopsin for spectral separation in multicolor optogenetics
LiteratureIt addresses the need for channelrhodopsins with more distant absorption wavelengths for multicolor optogenetics.
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It addresses the need for channelrhodopsins with more distant absorption wavelengths for multicolor optogenetics.
Published Workflows
Objective: Use structural and mechanistic insight from KnChR to develop blue-shifted channelrhodopsin variants and confirm optogenetic utility in neurons.
Why it works: The abstract links structural features of KnChR to spectral tuning and channel kinetics, then states that a rational approach was used to develop blue-shifted mutants and that neuronal activation was confirmed, implying structure-informed engineering followed by functional validation.
retinal chromophore configuration associated with blue shiftC-terminal allosteric modulation of channel kineticscryo-electron microscopyrational mutagenesisneuronal transfection and light activation testing
Taxonomy & Function
Primary hierarchy
Mechanism Branch
Architecture: A reusable architecture pattern for arranging parts into an engineered system.
Mechanisms
allosteric modulationconformational uncagingConformational Uncaginglight-gated ion channel activationTechniques
Structural CharacterizationTarget processes
No target processes tagged yet.
Input: Light
Implementation Constraints
cofactor dependency: requires exogenous cofactorencoding mode: genetically encodedimplementation constraint: context specific validationimplementation constraint: spectral hardware requirementoperating role: actuatorswitch architecture: uncaging
Use requires expression of KnChR in target cells and illumination with UV or deep-blue light. The paper also reports cryo-EM structural analysis and rational mutagenesis around the protein.; requires light stimulation with UV or deep-blue light; reported neuronal use is in KnChR-transfected precultured neurons
Requires extra cofactor or chromophore handling. Needs compatible illumination hardware and optical access. Independent follow-up evidence is still limited. Validation breadth across biological contexts is still narrow. Independent reuse still looks limited, so the evidence base may be fragile. It may depend on an exogenous cofactor or chromophore supply step.
Validation
Cell-freeBacteriaMammalianMouseHumanTherapeuticIndep. Replication
Observations
successPrimary Cellsapplication demoprecultured neurons
light activation
Inferred from claim c6 during normalization. UV or deep-blue light activates KnChR-transfected precultured neurons. Derived from claim c6.
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Supporting Sources
Ranked Claims
UV or deep-blue light activates KnChR-transfected precultured neurons.
The 6-s-cis configuration of the retinal chromophore in KnChR contributes to its blue-shifted action spectrum.
The unique C-terminal architecture of KnChR is involved in allosteric modulation of channel kinetics.
KnChR is one of the most blue-shifted channelrhodopsins.
KnChR was resolved by cryo-EM at 2.7 Å resolution.
cryo-EM resolution 2.7 Å
Approval Evidence
1 source5 linked approval claimsfirst-pass slug knchr
Here we report the 2.7 Å-resolution cryo-electron microscopy structure of a ChR from Klebsormidium nitens (KnChR), which is one of the most blue-shifted ChRs.
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application demosupports
UV or deep-blue light activates KnChR-transfected precultured neurons.
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mechanistic inferencesupports
The 6-s-cis configuration of the retinal chromophore in KnChR contributes to its blue-shifted action spectrum.
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mechanistic inferencesupports
The unique C-terminal architecture of KnChR is involved in allosteric modulation of channel kinetics.
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spectral propertysupports
KnChR is one of the most blue-shifted channelrhodopsins.
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structural characterizationsupports
KnChR was resolved by cryo-EM at 2.7 Å resolution.
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Comparisons
Source-stated alternatives
The abstract refers broadly to other channelrhodopsins used in multicolor optogenetics but does not name specific alternatives in the abstract.
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The abstract refers broadly to other channelrhodopsins used in multicolor optogenetics but does not name specific alternatives in the abstract.
Source-backed strengths
one of the most blue-shifted channelrhodopsins; can be activated by UV or deep-blue light in transfected precultured neurons
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one of the most blue-shifted channelrhodopsins
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can be activated by UV or deep-blue light in transfected precultured neurons
Compared with optogenetic functional interrogation
The abstract refers broadly to other channelrhodopsins used in multicolor optogenetics but does not name specific alternatives in the abstract.
Shared frame: source-stated alternative in extracted literature
Strengths here: one of the most blue-shifted channelrhodopsins; can be activated by UV or deep-blue light in transfected precultured neurons.
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The abstract refers broadly to other channelrhodopsins used in multicolor optogenetics but does not name specific alternatives in the abstract.
Compared with optogenetic membrane potential perturbation
The abstract refers broadly to other channelrhodopsins used in multicolor optogenetics but does not name specific alternatives in the abstract.
Shared frame: source-stated alternative in extracted literature
Strengths here: one of the most blue-shifted channelrhodopsins; can be activated by UV or deep-blue light in transfected precultured neurons.
Source:
The abstract refers broadly to other channelrhodopsins used in multicolor optogenetics but does not name specific alternatives in the abstract.
Ranked Citations
- 1.