Recombinant Pongo abelii Protein FAM210A (FAM210A)

What is FAM210A and what is its subcellular localization?

FAM210A (Family with sequence similarity 210 member A) is a mitochondrial protein that contains a mitochondrial targeting signal (MTS) at its N-terminus, followed by a transmembrane domain, a Domain of Unknown Function (DUF1279), and a coiled-coil domain at its C-terminus . The protein is localized to the mitochondrial inner membrane as confirmed by multiple studies investigating its role in mitochondrial function . When studying FAM210A localization, researchers should employ mitochondrial fractionation techniques followed by immunoblotting or immunofluorescence with appropriate mitochondrial markers to confirm its precise submitochondrial localization.

What are the structural characteristics of the Pongo abelii (Sumatran orangutan) FAM210A protein?

The Pongo abelii FAM210A protein consists of 272 amino acids and shares high homology with human FAM210A . The full amino acid sequence includes: MQWNVPRTVSRLARRTCLEPHNAGLFGRCQNVKGPLLLYNAESKAVLVQGSQKQWLHLSAAQCVAKERRPLDAHPPQPGVLRHKQGKQHVSFRRVFSSNATAQGTPEKKEEPDPLQDKSISLYQRFKKTFRQYGKVLIPVHLITSGVWFGTFYYAALKGVNVVPFLELIGLPDSVVSILKNSQSGNALTAYALFKIATPARYTVTLGGTSVTVKYLRSHGYMSTPPPVKEYLQDRMEETKELITEKMEETKDRLTEKLQETKEKVSFKKKVE . When working with this recombinant protein, researchers should consider using appropriate storage conditions (typically at -20°C with 50% glycerol in Tris-based buffer) to maintain stability and functionality for experimental applications.

What physiological roles has FAM210A been implicated in across different tissues?

FAM210A has been shown to play critical roles in multiple tissue systems:

• Cardiac Tissue: Regulates mitochondrial translation and maintains cardiac function. Fam210a deficiency in cardiomyocytes induces progressive dilated cardiomyopathy and heart failure .

• Skeletal Muscle: Essential for protein synthesis and muscle growth by mediating inter-organelle crosstalk between mitochondria and ribosomes. Muscle-specific knockout causes severe growth retardation, progressive muscle atrophy, and premature death in mice .

• Bone Development: Functions as a determinant of bone structure and strength. Genetic studies have associated FAM210A variants with bone mineral density and fracture risk in humans .

• Brown Adipose Tissue (BAT): Critical for cold-induced mitochondrial remodeling and thermogenesis. FAM210A governs OPA1 cleavage by modulating YME1L/OMA1 activity to facilitate mitochondrial cristae dynamics during thermogenic responses .

When investigating FAM210A's role in specific tissues, researchers should design tissue-specific knockout models and employ multi-omics approaches to comprehensively characterize its functional impacts.

How does FAM210A regulate mitochondrial translation and what are the optimal methods to investigate this process?

FAM210A plays a crucial role in regulating mitochondrial mRNA translation. Research demonstrates that FAM210A loss of function compromises mitochondrial mRNA translation leading to reduced mitochondrial-encoded proteins and disrupted proteostasis . To investigate this process, researchers should employ:

• Mitochondrial Polysome Profiling: This technique allows for the isolation of mitochondrial ribosomes engaged in active translation. In FAM210A functional studies, this approach revealed compromised mitochondrial mRNA translation upon FAM210A deficiency .

• Mitochondrial Translation Assays: These involve pulse-labeling of newly synthesized mitochondrial proteins with radioactive amino acids or non-radioactive analogs like puromycin, followed by detection via autoradiography or immunoblotting.

• Ribosome-Mitochondria Proximity Analysis: Since FAM210A mediates inter-organelle crosstalk between mitochondria and ribosomes, techniques like proximity ligation assays or FRET-based approaches can detect and quantify these interactions.

• Multi-omics Approaches: Integrating transcriptomics, proteomics, and metabolomics data provides a comprehensive view of how FAM210A deficiency affects mitochondrial function at multiple levels, as demonstrated in cardiac studies where FAM210A deficiency activated integrated stress response (ISR) leading to multi-omic reprogramming .

What phenotypic changes occur in muscle-specific FAM210A knockout models and how should these be quantitatively assessed?

Muscle-specific FAM210A knockout (Fam210a^MKO) mice exhibit several significant phenotypic changes that can be quantitatively assessed using the following methodologies:

• Growth Retardation Assessment:

  • Body weight monitoring shows 26.0% and 54.1% reduction at 4 and 6 weeks respectively compared to wild-type controls

  • Lean mass measurement using EchoMRI reveals 32.5% and 56.6% reduction at 4 and 6 weeks

  • Skeletal muscle weight measurement shows decreased TA muscle weight with 42.5% and 75.4% reduction at 4 and 6 weeks

• Muscle Fiber Analysis:

  • Cross-sectional immunofluorescence analysis using α-laminin staining to outline myofiber boundaries

  • Unbiased quantification of cross-sectional area (CSA) with size distribution analysis showing that while >60% of wild-type myofibers were larger than 500 μm² at 6-8 weeks, only <10% of Fam210a^MKO myofibers reached this size

• Functional Assessment:

  • Grip strength tests show significantly reduced performance

  • Ex vivo muscle contractility testing demonstrating maximal absolute force reduction of 68.9% in EDL and 32.8% in SOL muscles

  • Specific contractile force analysis (normalized by muscle CSA) showing decreases of 42.1% in EDL and 19.4% in SOL muscles

• Metabolic Evaluation:

  • Indirect calorimetry revealing increased oxygen consumption (VO₂) and carbon dioxide production (VCO₂)

  • Glucose tolerance testing showing lower fasting glucose levels but altered glucose clearance rates

How does FAM210A contribute to mitochondrial cristae remodeling during thermogenesis and what experimental approaches best characterize this function?

FAM210A is essential for cold-induced mitochondrial remodeling in brown adipose tissue (BAT). During thermogenesis, FAM210A governs OPA1 cleavage by modulating YME1L/OMA1 activity to facilitate mitochondrial cristae dynamics under cold challenge . To characterize this function, researchers should employ:

• Electron Microscopy Analysis: To visualize and quantify changes in mitochondrial cristae morphology in response to cold exposure in wild-type versus FAM210A-deficient BAT.

• Biochemical Analysis of OPA1 Processing: Monitor OPA1 cleavage patterns through immunoblotting to assess how FAM210A regulates the balance between long and short OPA1 forms.

• YME1L/OMA1 Activity Assays: Using in vitro protease activity assays with recombinant proteins or cellular systems to determine how FAM210A modulates these mitochondrial proteases.

• Cell-free Protein Expression Systems: As demonstrated in the research, combining this with biochemical and pharmacological inhibition assays in vitro and in vivo can elucidate the molecular mechanisms by which FAM210A influences protease activity .

• Thermal Imaging and Body Temperature Monitoring: To assess the physiological consequences of impaired thermogenesis in FAM210A-deficient models during cold exposure.

What is the relationship between FAM210A, protein acetylation, and ribosomal function in skeletal muscle?

FAM210A mediates a novel crosstalk between mitochondria and ribosomes that affects protein synthesis and muscle growth. Research shows that:

• Mitochondria-Ribosome Interaction: FAM210A appears to facilitate communication between mitochondria and ribosomes, which is essential for coordinated protein synthesis in skeletal muscle .

• Protein Acetylation Regulation: Transplantation of mitochondria from Fam210a^MKO mice into wild-type myoblasts is sufficient to elevate protein acetylation in recipient cells, suggesting FAM210A influences acetylation status of proteins involved in translation .

• Experimental Approaches to Study This Relationship:

  • Proximity labeling techniques (BioID, APEX) to identify proteins in proximity to FAM210A at the mitochondria-ribosome interface

  • Protein acetylome analysis using mass spectrometry to identify specific proteins with altered acetylation patterns in FAM210A-deficient models

  • Polysome profiling coupled with RNA-seq to assess global translation efficiency

  • Mitochondrial transplantation experiments followed by acetylation status analysis

  • Ribosome assembly and function assays to determine how FAM210A-mediated changes in protein acetylation affect translation efficiency

How do human FAM210A mutations correlate with sarcopenia and bone disorders, and what are appropriate models for studying these conditions?

Human FAM210A mutations have been associated with sarcopenia and bone disorders through genome-wide association studies (GWAS) . To study these correlations:

• GWAS Data Analysis:

  • Research shows SNPs in the FAM210A genomic region are significantly associated with bone mineral density (eBMD) (rs1941749, P = 3.5 × 10⁻⁴³) and fracture risk (rs4796995, P = 8.8 × 10⁻¹³)

  • Nearby SNPs (rs9955264 and rs1284201) are associated with appendicular lean mass and whole body lean mass

• Appropriate Research Models:

  • Patient-derived primary cells: Obtaining muscle or bone cells from patients with FAM210A mutations for functional studies

  • CRISPR-engineered cellular models: Introducing specific human mutations into relevant cell lines

  • Knock-in mouse models: Generating mice with human FAM210A mutations to study phenotypic effects on bone and muscle

  • iPSC-derived models: Differentiating induced pluripotent stem cells from patients or engineered with specific mutations into muscle and bone lineages

• Integrated Phenotyping Approaches:

  • Dual-energy X-ray absorptiometry (DXA) for bone mineral density assessment

  • Micro-CT analysis for bone microarchitecture

  • Biomechanical testing for bone strength evaluation

  • Muscle function testing including grip strength and contractile force measurements

  • Histological analysis of both bone and muscle tissues

  • Biochemical markers of bone turnover and muscle metabolism

What are the optimal storage and handling conditions for recombinant Pongo abelii FAM210A protein in experimental settings?

When working with recombinant Pongo abelii FAM210A protein, researchers should adhere to the following storage and handling guidelines:

• Storage Temperature: Store the protein at -20°C for regular use, and at -80°C for extended storage to minimize protein degradation .

• Buffer Composition: The protein is typically supplied in a Tris-based buffer with 50% glycerol that has been optimized for this specific protein . This formulation helps maintain protein stability and prevent freeze-thaw damage.

• Freeze-Thaw Cycles: Repeated freezing and thawing should be avoided as it can lead to protein denaturation and loss of activity . It is recommended to prepare small working aliquots that can be stored at 4°C for up to one week to minimize freeze-thaw cycles.

• Experimental Conditions: When designing experiments, researchers should consider maintaining physiologically relevant conditions that preserve the native conformation and function of FAM210A, particularly its mitochondrial localization and transmembrane domain integrity.

• Quality Control: Before using in critical experiments, verify protein integrity by SDS-PAGE and functional assays appropriate to the specific research question being addressed.

What multi-omics approaches provide the most comprehensive insights into FAM210A function, and how should the resulting data be integrated?

Multi-omics approaches have proven valuable in elucidating FAM210A function across different physiological contexts. Based on the research data:

• Recommended Multi-omics Platforms:

  • Transcriptomics: RNA-seq to identify genes differentially expressed in FAM210A-deficient models

  • Proteomics: Quantitative proteomics to identify changes in protein abundance and post-translational modifications

  • Translatome Analysis: Ribosome profiling to assess translation efficiency

  • Metabolomics: Targeted and untargeted metabolite profiling to identify metabolic changes

  • Mitochondrial Proteomics: Specialized proteomic analysis of isolated mitochondria to identify mitochondrial protein changes

• Data Integration Strategies:

  • Pathway Enrichment Analysis: Identify biological pathways affected across multiple omics layers

  • Network Analysis: Construct protein-protein interaction networks to identify key regulatory nodes

  • Correlation Analysis: Perform multi-omics correlation to identify coordinated changes

  • Causal Inference Models: Apply statistical approaches to infer causal relationships between different omics layers

• Application Example: In cardiac studies, multi-omics analyses revealed that FAM210A deficiency persistently activates integrated stress response (ISR), resulting in coordinated transcriptomic, translatomic, proteomic, and metabolomic reprogramming, ultimately leading to heart failure progression . This demonstrates how integrating multiple data types provides a more comprehensive understanding than any single approach.