Recombinant Bovine Transmembrane protein 150C (TMEM150C)

What is the evolutionary conservation of TMEM150C across species?

TMEM150C shows remarkable evolutionary conservation among vertebrates. Research has demonstrated that duck TMEM150C (dTMEM150C) shares 87% sequence identity with mouse TMEM150C . More importantly, functional studies revealed that duck TMEM150C exhibits similar modulatory effects on mechanosensitive channels when compared to its mouse counterpart, including the ability to:

• Decrease the apparent threshold of Piezo2 mechanical activation from 5.3 ± 0.3 μm to 3.6 ± 0.5 μm

• Prolong inactivation time constants (τ inact) in the 5–10 μm indentation range from 3.4–3.9 ms to 9.0–21.2 ms

This functional conservation suggests TMEM150C plays an evolutionarily conserved role in mechanosensation across vertebrate species, making findings from model organisms potentially applicable to bovine research.

What are the primary physiological functions of TMEM150C?

The physiological role of TMEM150C remains somewhat controversial, with different research groups reporting conflicting findings:

Evidence supporting a regulatory role:

• TMEM150C significantly prolongs the duration of mechano-current produced by multiple mechanogated channels (Piezo2, Piezo1, and TREK-1)

• It decreases the apparent activation threshold in Piezo2

• It induces persistent current in Piezo1

• It is co-expressed with Piezo2 in trigeminal neurons

Contradictory findings:

• Some researchers failed to evoke mechanosensitive currents in cells expressing TMEM150C alone using three different mechanical stimulation methods

• TMEM150C knockout mice showed no quantitative alterations in cutaneous sensory fiber properties

• No gait abnormalities were observed in TMEM150C knockout mice

The current consensus leans toward TMEM150C functioning as a modulator of mechanosensitivity rather than a mechanosensitive channel itself, though its precise physiological role requires further investigation.

How does TMEM150C interact with mechanogated ion channels?

TMEM150C appears to interact functionally and physically with multiple mechanogated ion channels. The following table summarizes key interactions:

Biochemical evidence suggests TMEM150C forms a complex with these channels, as it co-immunoprecipitates with both TREK-1 and Piezo2 . This indicates TMEM150C may function as a general regulator of mechanogated ion channels from different classes, potentially through direct physical interaction.

What methodologies are most effective for studying TMEM150C's role in mechanosensitivity?

Based on published research, multiple complementary approaches have proven effective for investigating TMEM150C function:

Electrophysiological Techniques:

• Indentation-evoked mechanically activated (MA) currents

• High-speed pressure clamp (HSPC)

• Substrate deflection methods

• Voltage-dependent measurements to analyze inactivation properties

Molecular Biology Approaches:

• Co-expression studies in heterologous systems (HEK293T ΔP1 cells)

• Generation of knockout models via CRISPR/Cas9

• Co-immunoprecipitation to demonstrate physical interactions

Behavioral and Functional Assays:

• Ex vivo skin nerve preparation to characterize mechanoreceptor function

• Quantitative gait analysis to assess proprioceptor function

Researchers should consider implementing multiple methodologies, as contradictory findings between different research groups highlight the importance of comprehensive experimental approaches .

What controversies exist regarding TMEM150C function in mechanosensation?

The scientific literature reveals significant controversies regarding TMEM150C's function:

Original Hypothesis:

• TMEM150C was initially proposed to mediate mechano-activated current in proprioceptive neurons

• Later research suggested it functions as a regulator of mechanogated ion channels rather than an ion channel itself

Contradictory Findings:

• Some researchers could not evoke mechanosensitive currents in cells expressing TMEM150C alone

• TMEM150C knockout mice showed no mechanosensory phenotypes, challenging the notion of its requirement for normal proprioceptor function

• Questions exist about the completeness of gene ablation in some knockout models

These controversies highlight the need for further research using improved models and methodologies to clarify TMEM150C's precise role in mechanosensation.

What are the optimal conditions for expression and purification of recombinant TMEM150C?

Based on available data for recombinant mouse TMEM150C, the following conditions have been successfully employed:

Expression System:

• E. coli expression system with N-terminal His tag

Purification and Storage:

• Protein provided as lyophilized powder

• Storage at -20°C/-80°C upon receipt

• Aliquoting necessary for multiple use to avoid repeated freeze-thaw cycles

• Storage buffer: Tris/PBS-based buffer with 6% Trehalose, pH 8.0

Reconstitution Protocol:

• Briefly centrifuge vial prior to opening

• Reconstitute in deionized sterile water to 0.1-1.0 mg/mL

• Add 5-50% glycerol (final concentration) for long-term storage

• Default recommendation: 50% final glycerol concentration

Quality Control Parameters:

• Purity greater than 90% as determined by SDS-PAGE

While these specifications were developed for mouse TMEM150C, they provide a starting point for researchers working with bovine TMEM150C, though optimization may be necessary for species-specific applications.

What approaches are most effective for studying TMEM150C-ion channel interactions?

The following experimental approaches have proven effective for investigating TMEM150C-ion channel interactions:

Co-expression Systems:

• Heterologous expression in HEK293T ΔP1 cells (Piezo1-knockout HEK293T cells)

• Co-transfection of TMEM150C with target ion channels (Piezo1, Piezo2, TREK-1)

Electrophysiological Analysis:

• Multiple mechanical stimulation methods:

  • Indentation with a glass probe

  • High-speed pressure clamp (HSPC)

  • Substrate deflection

• Key parameters to measure:

  • Activation threshold

  • Inactivation time constant (τ inact)

  • Current-voltage relationships

  • Peak current amplitude

Biochemical Methods:

• Co-immunoprecipitation to demonstrate physical interaction

• This approach has successfully shown that TMEM150C forms complexes with channels like TREK-1 and Piezo2

Essential Controls:

• Expression of TMEM150C alone to verify lack of inherent channel activity

• Expression of ion channels without TMEM150C for baseline comparisons

• Analysis of voltage dependence to confirm current identity

How can researchers effectively generate and validate TMEM150C knockout models?

Based on published research, two approaches for generating TMEM150C knockout models have been used, with important considerations for validation:

Generation Methods:

• LacZ Cassette Insertion:

  • Insertion of a LacZ cassette with splice acceptor into the TMEM150C locus

  • Caution: Analysis showed incomplete gene ablation in some tissues

• CRISPR/Cas9 Gene Editing:

  • Deletion of a large portion of the TMEM150C gene

  • More successful in producing complete knockout in dorsal root ganglia

Comprehensive Validation Strategy:

• Molecular Validation:

  • DNA-level verification of gene deletion

  • Transcript analysis by RT-PCR

  • Protein expression analysis using validated antibodies

• Functional Validation:

  • Ex vivo tissue preparations to assess mechanosensitivity

  • Behavioral assessment of relevant sensory functions

  • Electrophysiological characterization

Important Considerations:

• Verify knockout completeness in all relevant tissues

• Consider potential compensatory mechanisms

• Be aware that phenotypes may differ from predictions based on in vitro studies

How might species differences affect TMEM150C research applications?

• While core functions appear conserved, species-specific differences in regulation, expression patterns, or protein interactions may exist

• Comparative studies between species can reveal evolutionarily conserved domains critical for function

• Cross-species validation of key findings strengthens translational relevance

For bovine TMEM150C specifically, researchers should:

• Compare sequence homology with well-studied orthologs

• Validate functional properties in bovine-derived systems when possible

• Consider potential tissue-specific expression differences between species

What are the challenges in reconciling in vitro versus in vivo findings for TMEM150C?

A significant research challenge is the apparent discrepancy between robust in vitro effects and limited in vivo phenotypes:

In Vitro Evidence:

• TMEM150C significantly modulates multiple mechanosensitive ion channels

• Co-expression with Piezo1, Piezo2, or TREK-1 dramatically alters channel kinetics

• Physical interaction demonstrated via co-immunoprecipitation

In Vivo Contradictions:

• TMEM150C knockout mice show no apparent mechanosensory deficits

• No alterations in cutaneous sensory fiber properties

• Normal gait and proprioception in knockout animals

Possible explanations include:

• Compensatory mechanisms in vivo that mask knockout phenotypes

• Context-dependent functions not captured in simplified in vitro systems

• Subtle phenotypes requiring more sensitive detection methods

• Potential issues with knockout model completeness

Researchers should address these challenges through:

• Development of conditional knockout models

• Combined knockout of potential compensatory proteins

• More sensitive in vivo functional assays

• Careful validation of model systems

What are the most promising future research directions for TMEM150C?

Several promising research directions could advance our understanding of TMEM150C:

• Structural Biology Approaches:

  • Determining the three-dimensional structure of TMEM150C

  • Mapping interaction domains with partner channels

  • Structure-guided mutagenesis to identify functional domains

• Advanced Genetic Models:

  • Tissue-specific conditional knockouts

  • Knockin models with tagged endogenous protein

  • Combined knockout with potential redundant proteins

• Mechanistic Investigations:

  • Precise molecular mechanism of channel modulation

  • Identification of regulatory post-translational modifications

  • Lipid interactions and membrane microdomain associations

• Translational Applications:

  • Exploration of TMEM150C as a therapeutic target for pain or mechanosensory disorders

  • Development of selective modulators of TMEM150C-channel interactions

  • Comparative studies across species including bovine models