Toolkit/PILS-Nir1

PILS-Nir1

Construct Pattern·Research·Since 2025

Also known as: fluorescent PILS-Nir1

Taxonomy: Mechanism Branch / Architecture. Workflows sit above the mechanism and technique branches rather than replacing them.

Summary

We identified the lipin-like sequence of Nir1 (PILS-Nir1) as a candidate PA biosensor based on structural analysis of Nir1's LNS2 domain.

Usefulness & Problems

Why this is useful

PILS-Nir1 is a genetically encoded phosphatidic acid biosensor derived from the lipin-like sequence of Nir1. In cells, its membrane localization reports PA and supports real-time imaging of PA dynamics.; real-time phosphatidic acid dynamics in live cells; visualization of modest organelle-generated phosphatidic acid production

Source:

PILS-Nir1 is a genetically encoded phosphatidic acid biosensor derived from the lipin-like sequence of Nir1. In cells, its membrane localization reports PA and supports real-time imaging of PA dynamics.

Source:

real-time phosphatidic acid dynamics in live cells

Source:

visualization of modest organelle-generated phosphatidic acid production

Problem solved

It addresses the lack of high-affinity live-cell tools for phosphatidic acid and improves detection of modest PA production that existing biosensors missed.; lack of high-affinity tools to study phosphatidic acid in live cells; insufficient sensitivity of existing biosensors for modest phosphatidic acid production

Source:

It addresses the lack of high-affinity live-cell tools for phosphatidic acid and improves detection of modest PA production that existing biosensors missed.

Source:

lack of high-affinity tools to study phosphatidic acid in live cells

Source:

insufficient sensitivity of existing biosensors for modest phosphatidic acid production

Problem links

insufficient sensitivity of existing biosensors for modest phosphatidic acid production

Literature

It addresses the lack of high-affinity live-cell tools for phosphatidic acid and improves detection of modest PA production that existing biosensors missed.

Source:

It addresses the lack of high-affinity live-cell tools for phosphatidic acid and improves detection of modest PA production that existing biosensors missed.

lack of high-affinity tools to study phosphatidic acid in live cells

Literature

It addresses the lack of high-affinity live-cell tools for phosphatidic acid and improves detection of modest PA production that existing biosensors missed.

Source:

It addresses the lack of high-affinity live-cell tools for phosphatidic acid and improves detection of modest PA production that existing biosensors missed.

Published Workflows

PILS-Nir1 is a sensitive phosphatidic acid biosensor that reveals mechanisms of lipid production.

2025

Objective: Develop and validate a sensitive live-cell phosphatidic acid biosensor capable of detecting modest endogenous phosphatidic acid production.

Why it works: The workflow combines structure-guided candidate selection with in vitro binding tests and cellular perturbation-based validation, allowing the authors to separate biochemical lipid binding from the cellular determinant of membrane recruitment and then benchmark sensitivity against existing probes.

PA-dependent membrane localizationorganelle-generated PA detectionstructural analysis-guided candidate identificationin vitro liposome-binding assaypharmacological manipulationgenetic manipulationlive-cell fluorescent imagingbenchmarking against comparator probes

Stages

  1. 1.
    Structure-guided candidate identification(library_design)

    This stage provides a mechanistically motivated biosensor candidate before experimental testing.

    Selection: Structural analysis of Nir1's LNS2 domain identified the lipin-like sequence of Nir1 as a candidate PA biosensor.

  2. 2.
    In vitro lipid-binding characterization(functional_characterization)

    This stage establishes whether the candidate can bind relevant lipids before interpreting cellular localization behavior.

    Selection: Liposome-binding assays were used to test lipid binding by PILS-Nir1.

  3. 3.
    Cellular specificity testing by perturbation(secondary_characterization)

    This stage distinguishes cellular determinant of localization from broader in vitro binding behavior.

    Selection: Pharmacological and genetic manipulations in HEK293A cells expressing fluorescent PILS-Nir1 were used to determine which lipid is necessary and sufficient for membrane localization.

  4. 4.
    Comparator sensitivity benchmarking in signaling context(confirmatory_validation)

    This stage tests whether the candidate improves on existing PA biosensors in a biologically relevant application.

    Selection: PILS-Nir1 was compared with Spo20-based probes for sensitivity to organelle-generated PA during muscarinic receptor-PLD signaling.

Steps

  1. 1.
    Identify PILS-Nir1 from Nir1 LNS2 structural rationalecandidate biosensor

    Nominate a PA biosensor candidate from Nir1 sequence features.

    A structure-guided rationale is used first to choose a candidate before experimental characterization.

  2. 2.
    Test PILS-Nir1 lipid binding with liposome-binding assaysbiosensor under characterization

    Determine whether the candidate binds PA and other lipids in vitro.

    Biochemical binding is assessed before cellular interpretation to establish baseline lipid interaction behavior.

  3. 3.
    Use pharmacological and genetic manipulations in HEK293A cells expressing fluorescent PILS-Nir1biosensor under validation

    Determine which lipid is necessary and sufficient for membrane localization in cells.

    This follows in vitro binding because cellular perturbation is needed to resolve which lipid actually drives membrane localization in living cells.

  4. 4.
    Benchmark PILS-Nir1 against Spo20-based probes during muscarinic receptor-driven PLD signalingbiosensor and comparator probes

    Test whether PILS-Nir1 improves sensitivity for detecting endogenous organelle-generated PA.

    Comparator benchmarking is done after establishing cellular specificity so performance claims reflect a validated PA-responsive sensor.

Taxonomy & Function

Primary hierarchy

Mechanism Branch

Architecture: A reusable architecture pattern for arranging parts into an engineered system.

Target processes

localization

Implementation Constraints

cofactor dependency: cofactor requirement unknownencoding mode: genetically encodedimplementation constraint: context specific validationoperating role: sensor

The abstract supports use as a fluorescently expressed construct in HEK293A cells, with live-cell imaging and perturbations such as pharmacological or genetic manipulations. Liposome-binding assays were also used to characterize binding in vitro.; expressed as a fluorescent construct in HEK293A cells for live-cell localization readout; requires imaging of membrane localization as the biosensor output

The abstract indicates that PILS-Nir1 also binds PIP2 in vitro, so in vitro binding alone does not establish cellular specificity. The abstract does not show that it solves all specificity or deployment constraints across all cell types.; binds both PA and PIP2 in vitro

Validation

Cell-freeBacteriaMammalianMouseHumanTherapeuticIndep. Replication

Supporting Sources

Ranked Claims

Claim 1application capabilitysupports2025Source 1needs review

PILS-Nir1 enables visualization of modest phosphatidic acid production by PLD downstream of muscarinic receptors that was previously undetectable with existing biosensors.

enabling visualization of modest PA production by PLD downstream of muscarinic receptors-previously undetectable with existing biosensors
Claim 2binding specificitysupports2025Source 1needs review

PILS-Nir1 binds PA and PIP2 in vitro, but in cells only PA is necessary and sufficient for membrane localization.

while PILS-Nir1 binds PA and PIP2in vitro, only PA is necessary and sufficient for membrane localization in cells
Claim 3comparative performancesupports2025Source 1needs review

PILS-Nir1 has greater sensitivity to organelle-generated phosphatidic acid than Spo20-based probes.

PILS-Nir1 displayed greater sensitivity to organelle-generated PA than Spo20-based probes
Claim 4tool functionsupports2025Source 1needs review

PILS-Nir1 is a phosphatidic acid biosensor for live-cell imaging.

We identified the lipin-like sequence of Nir1 (PILS-Nir1) as a candidate PA biosensor

Approval Evidence

1 source4 linked approval claimsfirst-pass slug pils-nir1
We identified the lipin-like sequence of Nir1 (PILS-Nir1) as a candidate PA biosensor based on structural analysis of Nir1's LNS2 domain.

Source:

application capabilitysupports

PILS-Nir1 enables visualization of modest phosphatidic acid production by PLD downstream of muscarinic receptors that was previously undetectable with existing biosensors.

enabling visualization of modest PA production by PLD downstream of muscarinic receptors-previously undetectable with existing biosensors

Source:

binding specificitysupports

PILS-Nir1 binds PA and PIP2 in vitro, but in cells only PA is necessary and sufficient for membrane localization.

while PILS-Nir1 binds PA and PIP2in vitro, only PA is necessary and sufficient for membrane localization in cells

Source:

comparative performancesupports

PILS-Nir1 has greater sensitivity to organelle-generated phosphatidic acid than Spo20-based probes.

PILS-Nir1 displayed greater sensitivity to organelle-generated PA than Spo20-based probes

Source:

tool functionsupports

PILS-Nir1 is a phosphatidic acid biosensor for live-cell imaging.

We identified the lipin-like sequence of Nir1 (PILS-Nir1) as a candidate PA biosensor

Source:

Comparisons

Source-stated alternatives

The paper contrasts PILS-Nir1 with Spo20-based probes as existing PA biosensors. Those probes were less sensitive for detecting modest organelle-generated PA in the reported setting.

Source:

The paper contrasts PILS-Nir1 with Spo20-based probes as existing PA biosensors. Those probes were less sensitive for detecting modest organelle-generated PA in the reported setting.

Source-backed strengths

greater sensitivity to organelle-generated phosphatidic acid than Spo20-based probes; PA is necessary and sufficient for membrane localization in cells

Source:

greater sensitivity to organelle-generated phosphatidic acid than Spo20-based probes

Source:

PA is necessary and sufficient for membrane localization in cells

Compared with biosensors

The paper contrasts PILS-Nir1 with Spo20-based probes as existing PA biosensors. Those probes were less sensitive for detecting modest organelle-generated PA in the reported setting.

Shared frame: source-stated alternative in extracted literature

Strengths here: greater sensitivity to organelle-generated phosphatidic acid than Spo20-based probes; PA is necessary and sufficient for membrane localization in cells.

Relative tradeoffs: binds both PA and PIP2 in vitro.

Source:

The paper contrasts PILS-Nir1 with Spo20-based probes as existing PA biosensors. Those probes were less sensitive for detecting modest organelle-generated PA in the reported setting.

Compared with biosensors for active Rho detection

The paper contrasts PILS-Nir1 with Spo20-based probes as existing PA biosensors. Those probes were less sensitive for detecting modest organelle-generated PA in the reported setting.

Shared frame: source-stated alternative in extracted literature

Strengths here: greater sensitivity to organelle-generated phosphatidic acid than Spo20-based probes; PA is necessary and sufficient for membrane localization in cells.

Relative tradeoffs: binds both PA and PIP2 in vitro.

Source:

The paper contrasts PILS-Nir1 with Spo20-based probes as existing PA biosensors. Those probes were less sensitive for detecting modest organelle-generated PA in the reported setting.

Compared with fluorescent protein based reporters and biosensors

The paper contrasts PILS-Nir1 with Spo20-based probes as existing PA biosensors. Those probes were less sensitive for detecting modest organelle-generated PA in the reported setting.

Shared frame: source-stated alternative in extracted literature

Strengths here: greater sensitivity to organelle-generated phosphatidic acid than Spo20-based probes; PA is necessary and sufficient for membrane localization in cells.

Relative tradeoffs: binds both PA and PIP2 in vitro.

Source:

The paper contrasts PILS-Nir1 with Spo20-based probes as existing PA biosensors. Those probes were less sensitive for detecting modest organelle-generated PA in the reported setting.

Compared with genetically engineered biosensors

The paper contrasts PILS-Nir1 with Spo20-based probes as existing PA biosensors. Those probes were less sensitive for detecting modest organelle-generated PA in the reported setting.

Shared frame: source-stated alternative in extracted literature

Strengths here: greater sensitivity to organelle-generated phosphatidic acid than Spo20-based probes; PA is necessary and sufficient for membrane localization in cells.

Relative tradeoffs: binds both PA and PIP2 in vitro.

Source:

The paper contrasts PILS-Nir1 with Spo20-based probes as existing PA biosensors. Those probes were less sensitive for detecting modest organelle-generated PA in the reported setting.

Ranked Citations

  1. 1.
    StructuralSource 1MED2025Claim 1Claim 2Claim 3

    Extracted from this source document.