tmem117 Antibody

What is TMEM117 and why is it significant for research?

TMEM117 (Transmembrane Protein 117) is a protein expressed in various tissues that plays important regulatory roles in cellular processes including endoplasmic reticulum (ER) stress, reactive oxygen species (ROS) production, and calcium signaling. Recent research has identified TMEM117 as a marker for arginine vasopressin (AVP) magnocellular neurons in the hypothalamus and as a regulator of glucagon secretion in response to hypoglycemia . Additionally, TMEM117 has been implicated in cardiac hypertrophy through modulation of mitochondrial function . These diverse functions make TMEM117 a significant target for research across multiple fields including neuroscience, endocrinology, and cardiovascular research.

What applications are TMEM117 antibodies validated for?

Current commercial TMEM117 antibodies are primarily validated for Western Blotting (WB), immunofluorescence (IF), and ELISA applications . Specific applications include:

Research has successfully employed these antibodies for immunolabeling in brain sections (hypothalamic nuclei) , visualization of protein distribution in subcellular compartments, and quantification of expression levels in various experimental models .

What species reactivity is available for TMEM117 antibodies?

Current commercial antibodies show reactivity with different species, with most antibodies recognizing human, mouse, and rat TMEM117 . Some antibodies demonstrate broader cross-reactivity with specimens from various mammals:

When selecting an antibody for cross-species applications, researchers should verify the validation status for their specific species of interest .

How should I optimize Western blot protocols for TMEM117 detection?

For optimal Western blot detection of TMEM117, consider these methodology points:

What are the best methods for validating TMEM117 antibody specificity?

Validation of TMEM117 antibody specificity is critical for reliable research results. Recommended validation approaches include:

• Genetic knockout controls: Use tissues or cells from TMEM117 knockout models as negative controls. Research has confirmed antibody specificity using "lack of signal in brains of mice with Tmem117 gene inactivation" .

• siRNA knockdown: Transfection with TMEM117-targeting siRNA provides an alternative validation approach when knockout models are unavailable .

• Overexpression systems: Complementary to knockdown approaches, overexpression of tagged TMEM117 can confirm antibody specificity.

• Peptide competition: Pre-incubation of the antibody with the immunizing peptide should block specific immunoreactivity.

• Cross-reactivity testing: For multi-species studies, validation in each species is important, as epitope conservation may vary.

What fixation and immunostaining protocols work best for TMEM117 detection in tissue sections?

For optimal immunofluorescence detection of TMEM117 in tissue sections:

• Fixation: Paraformaldehyde fixation (4%) has been successfully used in studies examining TMEM117 expression in hypothalamic nuclei .

• Antigen retrieval: May be necessary depending on fixation duration and tissue type.

• Blocking: Use appropriate blocking reagents to minimize background, particularly important for brain tissue with high lipid content.

• Antibody incubation: Primary antibody incubation at 4°C overnight often yields optimal results for transmembrane proteins.

• Co-localization studies: TMEM117 has been successfully co-localized with AVP in magnocellular neurons, allowing for cell-type specific expression analysis .

Research has shown that TMEM117 displays "a punctuated intracellular distribution... which colocalized in part with AVP granules in both the soma and axons of magnocellular neurons" , suggesting careful attention to subcellular distribution is important for interpretation.

How can TMEM117 antibodies be used to study its role in ER stress and oxidative stress pathways?

TMEM117 has been identified as a regulator of ER stress and ROS production. Researchers can employ TMEM117 antibodies to investigate these pathways through:

• Correlation studies: Examine correlation between TMEM117 expression levels and markers of ER stress (sXbp1, BiP, calnexin) across different experimental conditions . Research has shown that "a small reduction in Tmem117 mRNA levels (log 2fold approximately −0.5) robustly increased expression of the ER stress markers sXbp1 and BiP" .

• Subcellular co-localization: Use co-immunostaining with markers of ER compartments to examine TMEM117 dynamics during stress conditions.

• Time-course experiments: Monitor TMEM117 expression changes during the induction and resolution of ER stress.

• Intervention studies: Compare ER stress markers in TMEM117 knockout/knockdown vs. wild-type/control cells under stress conditions. Research has demonstrated that "TMEM117 deficiency mitigated mitochondrial injury in hypertrophic hearts and cardiomyocyte" .

• ROS measurements: Combine TMEM117 immunostaining with ROS indicators like dihydroethidium (DHE) to correlate TMEM117 levels with oxidative stress at the cellular level .

Research has established that "TMEM117 silencing in this cell line did not increase ROS production, but Tmem117 overexpression significantly reduced ROS production" , suggesting complex regulatory relationships that warrant careful experimental design.

What approaches are recommended for studying TMEM117 in the context of calcium signaling?

TMEM117 has been implicated in calcium regulation, particularly in AVP neurons. Advanced approaches include:

• Calcium imaging with TMEM117 manipulation: Combine calcium indicators (like GCaMP) with TMEM117 knockdown/overexpression to directly assess its impact on calcium dynamics .

• In vivo fiber photometry: This technique has been successfully employed to monitor calcium signals in TMEM117-manipulated neurons during physiological challenges like hypoglycemia .

• Patch-clamp electrophysiology: When combined with TMEM117 antibody staining for post-hoc identification, this approach can correlate TMEM117 expression with electrophysiological properties .

Research has shown that "inactivation of Tmem117 induced a markedly higher baseline Ca²⁺ signal" , demonstrating the importance of TMEM117 in calcium homeostasis.

How can TMEM117 antibodies be applied in cardiovascular research?

Recent studies have implicated TMEM117 in cardiac hypertrophy and dysfunction. Advanced research applications include:

• Cardiac tissue analysis: Immunohistochemistry with TMEM117 antibodies can assess expression changes in models of cardiac disease .

• Cell-type specific expression: Co-staining with cardiac cell-type markers can identify which cardiac cells express TMEM117.

• Response to intervention: Monitor TMEM117 expression changes in response to therapeutic interventions for cardiac hypertrophy.

• Mitochondrial co-localization: As TMEM117 "modulate[s] mitochondrial membrane potential" , co-localization studies with mitochondrial markers can reveal functional relationships.

Research has demonstrated that "TMEM117 was upregulated in hypertrophic hearts and cardiomyocytes and TMEM117 deficiency attenuated Ang-II-induced cardiac hypertrophy in vivo" , suggesting therapeutic potential for TMEM117 targeting.

How should I address inconsistent TMEM117 antibody staining patterns?

Inconsistent staining patterns may arise from several factors:

• Protein expression variability: TMEM117 expression is regulated by physiological conditions, including ER stress . Research has shown that "TMEM117 protein expression during ER stress is transcriptionally regulated by PERK but not by ATF4" .

• Epitope masking: TMEM117 interactions with other proteins may mask epitopes under certain conditions.

• Fixation sensitivity: Different fixation methods may reveal different epitopes or subcellular pools of TMEM117.

• Antibody batch variation: Validate new antibody lots against previously successful experiments.

• Tissue processing variations: Standardize tissue collection and processing protocols across experiments.

To address these issues, researchers should:

• Compare multiple antibodies targeting different regions of TMEM117

• Include appropriate positive and negative controls in each experiment

• Verify findings with complementary techniques (e.g., mRNA expression)

• Consider physiological state of the tissue/cells when interpreting results

What are the key considerations when interpreting TMEM117 knockout/knockdown validation experiments?

When using genetic manipulation to validate TMEM117 antibodies or study TMEM117 function:

• Knockout efficiency assessment: Verify gene deletion at both genomic DNA and mRNA levels. Research has used "PCR analysis of genomic DNA" to confirm recombination in conditional knockout models .

• Cell viability concerns: Extended absence of TMEM117 may impact cell survival. Studies have noted that "most of the Cre-infected AVP neurons had disappeared during the postinfection period" in some TMEM117 knockout experiments , suggesting potential confounding effects.

• Compensation mechanisms: Chronic TMEM117 depletion may trigger compensatory changes in related pathways.

• Developmental effects: Constitutive knockout may have different effects than acute knockdown in adult tissues.

• Residual protein detection: Even with efficient gene knockout, residual protein may persist depending on protein half-life.

How can I resolve discrepancies in TMEM117 molecular weight detection?

The calculated molecular weight of TMEM117 is approximately 60 kDa (514 amino acids), but the observed molecular weight in Western blots typically ranges from 45-50 kDa . To address molecular weight discrepancies:

• Post-translational modifications: Investigate glycosylation or other modifications that may alter migration.

• Protein processing: Determine if TMEM117 undergoes proteolytic processing in your experimental system.

• Sample preparation: Test different protein extraction methods to ensure complete solubilization.

• Loading controls: Include positive control samples with known TMEM117 expression.

• Denaturing conditions: Optimize SDS concentration and reducing conditions.

• Multiple antibodies: Use antibodies targeting different regions of TMEM117 to verify band identity.

How might TMEM117 antibodies contribute to understanding its role in glucose regulation?

TMEM117 has been implicated in regulating the counterregulatory response to hypoglycemia through its expression in AVP neurons . Future research might:

• Cell-type specific expression mapping: Use TMEM117 antibodies to characterize expression across different glucose-sensing cells in multiple tissues.

• Phosphorylation state analysis: Develop phospho-specific TMEM117 antibodies to examine its activation in response to glucose fluctuations.

• Protein interactome studies: Employ co-immunoprecipitation with TMEM117 antibodies to identify binding partners in glucose-sensing cells.

• Hormone secretion correlation: Combine TMEM117 immunostaining with hormone secretion assays to establish quantitative relationships between expression and function.

Research has shown that "Tmem117 inactivation in AVP magnocellular neurons triggered ER stress, increased ROS production, intracellular Ca²⁺ levels, and AVP mRNA levels" , suggesting complex regulatory mechanisms that warrant further investigation.

What approaches might be used to develop therapeutic applications targeting TMEM117?

Based on emerging roles of TMEM117 in pathophysiology:

• Cardiac hypertrophy therapy: Research has suggested that "downregulation of TMEM117 may be a new therapeutic strategy for the prevention and treatment of cardiac hypertrophy" , warranting development of targeted approaches.

• Target validation: Use highly specific antibodies to confirm localization and expression levels in disease states.

• Therapeutic antibody development: Consider developing function-blocking antibodies against extracellular domains of TMEM117.

• Biomarker potential: Explore whether TMEM117 levels (detected by antibodies) could serve as biomarkers for diseases involving ER stress, mitochondrial dysfunction, or hypoglycemia counterregulation.

• Delivery mechanisms: Develop methods to target therapeutic agents to TMEM117-expressing cells in specific tissues.

How can multi-omics approaches be combined with TMEM117 antibody studies?

Integrating multiple -omics approaches with antibody-based studies can provide comprehensive understanding of TMEM117 function:

• Transcriptomics correlation: Compare TMEM117 protein levels (by immunoblotting/immunohistochemistry) with mRNA expression profiles to identify post-transcriptional regulation.

• Proteomics integration: Use TMEM117 antibodies for immunoprecipitation followed by mass spectrometry to identify interaction partners under different conditions.

• Single-cell analysis: Combine single-cell transcriptomics with TMEM117 immunostaining to correlate protein expression with cell-specific gene signatures.

• Spatial transcriptomics: Integrate spatial transcriptomics with TMEM117 immunohistochemistry to map expression patterns in complex tissues.

• Functional genomics: Use CRISPR screens in combination with TMEM117 antibody-based assays to identify genetic modifiers of TMEM117 function.