Recombinant Mouse Transmembrane protein 143 (Tmem143)

Basic Research Questions

• What is Mouse TMEM143 and what are its key structural and functional characteristics?

  Mouse TMEM143 (Transmembrane protein 143) is a dual-pass protein containing two transmembrane domains. Based on homology with human TMEM143, it is predicted to reside in the mitochondria . The protein contains a domain of unknown function (DUF3754) within which the transmembrane domains reside . While specific mouse data is limited, the human protein is 459 amino acids in length (isoform a), has a molecular weight of approximately 51.6 kDa, and an isoelectric point of 9.7 .

  Methodologically, researchers should consider:

  • Confirming mitochondrial localization in mouse cells using subcellular fractionation and immunofluorescence

  • Analyzing protein topology using protease protection assays

  • Investigating functional roles through overexpression and knockdown studies in relevant cell types

• What is known about the gene structure and expression patterns of mouse TMEM143?

  The mouse TMEM143 gene structure likely resembles its human counterpart, which spans over 31,000 base pairs and contains multiple exons . In humans, there are five transcript variants, with variant 1 being the longest and coding for isoform a . While mouse-specific expression data is limited in the provided information, human TMEM143 shows high expression in skeletal muscle and heart tissue .

  For expression analysis in mouse tissues, researchers should:

  • Use quantitative RT-PCR with primers designed to detect all potential transcript variants

  • Perform Western blotting with validated antibodies across multiple tissue types

  • Consider transcript-specific detection methods to identify variant expression patterns

• How can recombinant mouse TMEM143 be effectively produced for research applications?

  Recombinant mouse TMEM143 protein can be produced in various expression systems for research purposes. Commercial sources offer recombinant mouse TMEM143 protein suitable for cell culture, in vitro studies, in vivo studies, benchmarking, drug discovery, and as positive controls for diagnostics .

  When producing recombinant mouse TMEM143, researchers should consider:

  Expression System	Advantages	Considerations for TMEM143
  Mammalian cells	Native-like post-translational modifications	Preferred for transmembrane proteins like TMEM143
  E. coli	High yield, cost-effective	May require refolding due to transmembrane domains
  Insect cells	Good for membrane proteins	Intermediate complexity and yield

  Optimal purification strategies should include careful detergent selection to maintain the integrity of transmembrane domains.

• What are the validated research applications for recombinant mouse TMEM143?

  Recombinant mouse TMEM143 protein has several research applications:

  • Cell culture studies to investigate mitochondrial functions

  • In vitro binding assays to identify interaction partners

  • Generation of antibodies for detection and localization studies

  • Positive controls for Western blotting and immunoassays

  • Investigation of potential roles in adipogenesis

  For adipogenesis studies, TMEM143 has been identified alongside other genes such as Haptoglobin (HP), Fatty acid binding protein 4 (FABP4), and Adipsin (CFD) . This suggests potential involvement in fat cell development pathways.

• What are the recommended storage and handling conditions for recombinant mouse TMEM143?

  Based on general recombinant protein handling practices and available information:

  • Store lyophilized protein at -20°C to -80°C for long-term storage

  • For reconstituted protein, store at +4°C for short-term use or -20°C~-80°C for long-term storage

  • Use a suitable buffer such as PBS for reconstitution

  • Avoid repeated freeze-thaw cycles by preparing single-use aliquots

  • Verify protein integrity before experiments using SDS-PAGE

  As a transmembrane protein, TMEM143 may require the presence of mild detergents in buffers to maintain solubility and prevent aggregation.

Advanced Research Questions

• How can researchers optimize experimental design to study TMEM143's predicted mitochondrial functions?

  To investigate TMEM143's predicted role in mitochondria:

  • Confirm subcellular localization through co-localization with established mitochondrial markers

  • Assess the impact of TMEM143 overexpression or knockdown on mitochondrial membrane potential

  • Measure oxygen consumption rates in cells with modified TMEM143 expression

  • Analyze mitochondrial morphology changes upon TMEM143 manipulation

  • Investigate potential interactions with known mitochondrial proteins

  The predicted mitochondrial target peptide at the N-terminus of TMEM143 suggests it may be imported into mitochondria, potentially playing a role in organelle function or biogenesis.

• What methodological approaches can be used to investigate TMEM143's role in adipogenic processes?

  TMEM143 has been identified in adipogenic transcriptome profiling studies alongside established adipocyte markers . To investigate its role:

  • Monitor TMEM143 expression during adipocyte differentiation using qRT-PCR and Western blotting

  • Perform knockdown or overexpression studies in preadipocyte cell lines (e.g., 3T3-L1)

  • Assess the impact on adipocyte differentiation markers (FABP4, CFD, HP)

  • Use ChIP assays to investigate transcription factor binding to the TMEM143 promoter during adipogenesis

  • Compare TMEM143 expression patterns with PPARγ binding sites, as PPARγ is a master regulator of adipogenesis

  Previous studies have identified TMEM143 alongside other adipogenic genes using ChIP-chip technology in mouse 3T3-L1 cells , suggesting potential co-regulation during fat cell development.

• What techniques are most effective for analyzing protein-protein interactions involving TMEM143?

  Due to TMEM143's transmembrane nature, specialized approaches for membrane protein interactions are recommended:

  • Proximity labeling methods (BioID, APEX) to identify proteins in the vicinity of TMEM143

  • Co-immunoprecipitation with appropriate detergents to maintain membrane protein solubility

  • Membrane yeast two-hybrid systems specifically designed for transmembrane proteins

  • Fluorescence resonance energy transfer (FRET) to detect direct interactions in living cells

  • Pull-down assays using recombinant TMEM143 as bait

  When designing constructs for these experiments, researchers should consider TMEM143's topology to ensure tags do not interfere with transmembrane domains or potential interaction surfaces.

• How can transcript variant analysis be applied to mouse TMEM143 research?

  Based on knowledge from human TMEM143, which has five transcript variants , mouse TMEM143 likely also has multiple variants. To investigate:

  • Design PCR primers to specifically amplify different potential splice variants

  • Perform 5' and 3' RACE to identify all transcript isoforms in tissues of interest

  • Quantify relative abundance of variants across tissues using qRT-PCR

  • Generate expression constructs for each variant to assess functional differences

  • Analyze potential differential regulation of variants under various physiological conditions

  The human TMEM143 transcript variants differ in their inclusion of exons, resulting in proteins with different N-terminal regions . Similar variation may exist in mouse, potentially affecting mitochondrial targeting efficiency.

• What approaches can be used to investigate the potential role of TMEM143 in disease models?

  Based on its predicted functions and expression patterns:

  • Generate conditional knockout mouse models to assess tissue-specific functions

  • Analyze TMEM143 expression in disease states affecting mitochondrial function

  • Investigate possible roles in metabolic disorders, given its connection to adipogenesis

  • Screen for TMEM143 mutations or expression changes in relevant disease tissues

  • Use recombinant TMEM143 in drug screening assays to identify potential modulators

  The potential involvement of TMEM143 in tumor suppression/expression and cancer regulation suggests it may be a valuable target for cancer research as well.

• How can researchers address challenges in functional characterization of mouse TMEM143?

  Functional characterization of TMEM143 presents several challenges:

  • Limited knowledge of physiological roles and binding partners

  • Difficulties in expressing and purifying full-length transmembrane proteins

  • Need for specialized assays to assess mitochondrial functions

  • Potential functional redundancy with related proteins

  To overcome these challenges:

  • Use multiple complementary approaches (biochemical, genetic, imaging)

  • Consider domain-specific studies if full-length protein is problematic

  • Develop robust cellular assays to measure specific aspects of mitochondrial function

  • Employ evolutionary conservation analysis to identify critical functional regions

  • Integrate multi-omics data to place TMEM143 in biological pathways

• What considerations are important when comparing mouse TMEM143 with orthologs from other species?

  When conducting cross-species comparative studies:

  Species	Available Information	Key Considerations
  Human	Gene structure, protein characteristics, tissue expression	Well-characterized reference for comparison
  European shrew	Gene sequence data available	Evolutionary comparison for conserved domains
  Other mammals	Recombinant proteins available for multiple species	Cross-reactivity testing for antibodies

  Researchers should:

  • Perform sequence alignments to identify conserved and divergent regions

  • Consider species-specific post-translational modifications

  • Validate antibodies for cross-reactivity before use

  • Use species-specific recombinant proteins as controls in comparative studies

  • Analyze conservation of interacting partners across species

  Such comparative approaches can provide insights into evolutionarily conserved functions versus species-specific adaptations of TMEM143.