Recombinant Bovine ADP/ATP translocase 1 (SLC25A4)

What is the basic structure and function of bovine SLC25A4?

SLC25A4, also called the adenine nucleotide translocator or ADP/ATP carrier, belongs to the mitochondrial carrier family (SLC25). It forms the largest solute carrier family in humans and functions as a membrane transport protein that imports ADP into the mitochondrial matrix and exports ATP to the cytoplasm . The protein consists of 297 amino acids and contains multiple transmembrane domains that form a central translocation pathway . The transport mechanism involves highly dynamic conformational changes with six mobile elements that alternate between cytoplasmic and matrix states, making the central substrate binding site alternately accessible to these compartments .

Recent structural studies have revealed that the carrier changes between distinct conformational states during its transport cycle, with the matrix-open state being recently solved in complex with the inhibitor bongkrekic acid . This structure has helped explain the function of highly conserved sequence features and demonstrated that the transport mechanism is unique to this carrier family .

How do recombinant bovine SLC25A4 variants differ from one another?

Research has identified two different bovine cDNAs that encode closely related homologues of the mitochondrial ADP/ATP translocase. These two protein variants differ in 33 amino acids out of 297 . At the nucleotide level, the coding regions of these cDNAs differ at 184 positions, reflecting both synonymous and non-synonymous substitutions . Additionally, these variants show extensive divergence in their 3' noncoding sequences, which differ significantly in both length and sequence content .

The expression patterns of these variants also differ considerably across bovine tissues. One gene predominates in heart muscle, while the other shows higher expression in intestine . This tissue-specific expression pattern suggests specialized roles for each variant in different physiological contexts and cellular environments.

What is the oligomeric state of functional SLC25A4 in mitochondrial membranes?

Contrary to earlier beliefs that the mitochondrial ADP/ATP carrier functions as a dimer or higher-order oligomer, recent evidence conclusively demonstrates that SLC25A4 exists and functions as a monomer in the mitochondrial inner membrane . Studies in yeast showed no negative dominance in transport when wild-type and mutant carriers were co-expressed, indicating that the carriers function independently from each other .

Furthermore, when the ADP/ATP carrier was tagged with different lengths of poly-histidine tags, the expression levels decreased with increasing tag length, and the growth rates of yeast strains expressing these modified carriers on non-fermentable carbon sources decreased with decreasing expression level . This observation demonstrates haploinsufficiency, further supporting the monomeric functional state of the carrier.

What are the optimal expression systems for recombinant bovine SLC25A4?

The choice of expression system for recombinant bovine SLC25A4 depends on the research objectives and downstream applications. Several successful expression strategies have been documented:

• Yeast Expression System: Saccharomyces cerevisiae strain WB-12, which lacks endogenous functional ADP/ATP carriers, has been successfully used to express the ADP/ATP carrier from Thermothelomyces thermophila (TtAac), which shares 51% identity with bovine ADP/ATP carrier . This expression system allows functional validation through complementation of the growth defect on non-fermentable carbon sources.

• Bacterial Expression System: The Lactococcus lactis bacterial expression system has been employed for functional studies of human SLC25A4 variants, which share high homology with bovine SLC25A4 . This system is advantageous for transport assays and inhibitor studies.

• Mammalian Cell Expression: For studies requiring post-translational modifications similar to the native protein, mammalian cell expression systems may be preferable, though specific protocols for bovine SLC25A4 were not detailed in the provided search results.

The selection should consider factors such as protein folding requirements, post-translational modifications, yield requirements, and the intended experimental use of the recombinant protein.

What purification strategies yield the highest purity and activity of recombinant bovine SLC25A4?

Purification of recombinant bovine SLC25A4 presents challenges due to its hydrophobic nature and multiple transmembrane domains. Based on successful approaches with homologous proteins, the following purification strategy is recommended:

• Detergent Selection: Maltose-neopentyl glycol detergents have shown superior performance in stabilizing the detergent-solubilized protein . These detergents improve the stability of the carrier during purification and crystallization attempts.

• State-Specific Inhibitors: Using state-specific inhibitors like bongkrekic acid (BKA) can lock the carrier in a specific conformation (matrix state), enhancing stability during purification .

• Affinity Purification: Incorporation of affinity tags such as poly-histidine tags facilitates purification, though care must be taken as tag length can affect expression levels and functionality .

• Protein Stabilization: For crystallization purposes, strategic mutations such as Q302K (mimicking the network residues found in human and bovine ADP/ATP carriers) have shown increased thermal stability of the BKA-inhibited protein .

The purified protein should be validated for folding, stability, and functionality using activity assays such as reconstitution into liposomes or fused membrane vesicles for transport measurements.

How can researchers assess the functional activity of purified recombinant SLC25A4?

Functional assessment of purified recombinant SLC25A4 is crucial to confirm that the protein maintains its native transport properties. Several approaches have been validated:

Transport Assay Using Fused Membrane Vesicles:

• Express the recombinant SLC25A4 in a suitable system (e.g., L. lactis)

• Prepare fused membrane vesicles containing the expressed protein

• Load the vesicles with ADP

• Measure the uptake of radiolabeled ADP in exchange for the loaded ADP

• Use specific inhibitors such as carboxyatractyloside as a control to confirm specificity

This approach has been successfully used to assess the impact of mutations on transport activity. For example, the p.Lys33Gln mutation completely abolished ADP transport despite normal expression and targeting to the membrane .

Expression Verification:
Confirm proper expression and membrane targeting using western blot analysis with specific antibodies against SLC25A4 or associated tags . This is particularly important when assessing the impact of mutations on protein expression and stability.

How do specific mutations in SLC25A4 affect its transport function?

Mutational analysis has provided crucial insights into structure-function relationships in SLC25A4. The transport mechanism of SLC25A4 involves the disruption and formation of matrix and cytoplasmic salt bridge networks in an alternating manner . Key findings include:

• The p.Lys33Gln Mutation: This mutation affects a highly conserved lysine residue that forms a salt bridge with Asp232 in the matrix network. The mutation to glutamine eliminates this interaction because glutamine is neutral and too short to form a hydrogen bond . Functional studies demonstrated that this mutation completely abolishes ADP transport activity despite normal protein expression and membrane targeting .

• Conserved Glutamine Brace: Below the salt bridge formed by Lys33 is Gln37, which forms a highly conserved glutamine brace. The p.Lys33Gln mutation also disrupts this structural element .

• C-terminal Residue Variations: Fungal ADP/ATP carriers typically have an atypical glutamine (Q302) instead of a lysine residue on the C-terminal end of H6, resulting in a weaker cytoplasmic salt-bridge network compared to human and bovine carriers. The Q302K mutation in Thermothelomyces thermophila ADP/ATP carrier (TtAac) increased thermal stability of the BKA-inhibited protein .

These findings highlight the critical importance of specific amino acid residues in maintaining the structural integrity and functional capability of the transport mechanism.

What is the correlation between SLC25A4 mutations and disease phenotypes?

SLC25A4 mutations are associated with a spectrum of human diseases, with different mutations leading to distinct clinical presentations. The correlation between mutations and phenotypes includes:

• Dominant Mutations in Adults: Associated with progressive external ophthalmoplegia (PEO) .

• Recessive Loss-of-Function Mutations: Cause cardiomyopathy and skeletal myopathy .

• De Novo Dominant Mutations in Neonates: Present with lactic acidosis, severe hypotonia, and respiratory failure .

• De Novo p.Lys33Gln Variant: Associated with a milder phenotype of childhood-onset skeletal myopathy without cardiomyopathy, encephalopathy, or ophthalmoplegia .

The milder phenotype observed with some mutations (like p.Lys33Gln) may be explained by compensatory expression of the wild-type allele and other isoforms partially offsetting the impaired function of the mutant variant .

What computational models best predict the impact of novel mutations on SLC25A4 function?

While the search results do not specifically address computational prediction models for SLC25A4 mutations, we can infer effective approaches based on the structural and functional data available:

• Structural Analysis of Salt Bridge Networks: Given the importance of salt bridge networks in the transport mechanism, computational models that assess the impact of mutations on these interactions would be valuable. The p.Lys33Gln mutation demonstrates how disruption of a single salt bridge can abolish transport activity .

• Molecular Dynamics Simulations: These could help predict how mutations affect the dynamic conformational changes that occur during the transport cycle, particularly the movement of the six mobile elements identified in structural studies .

• Conservation Analysis: The high conservation of certain residues across species (like Lys33) indicates their functional importance . Computational approaches that incorporate evolutionary conservation would be useful in predicting the impact of mutations.

• Integration of Structural and Clinical Data: Models that incorporate both structural information and clinical phenotype data could help predict the severity of novel mutations by comparing them to known pathogenic variants.

For optimal predictive power, computational models should incorporate the latest structural insights from the cytoplasmic and matrix-state structures, particularly focusing on residues involved in the salt bridge networks and substrate binding site.

How does the expression pattern of SLC25A4 vary across different bovine tissues?

Research has demonstrated distinct tissue-specific expression patterns for bovine SLC25A4 variants. The two genes encoding ADP/ATP translocase homologues show differential expression across bovine tissues:

• One gene predominates in heart muscle

• The other gene shows higher expression in intestine

This tissue-specific expression pattern has been demonstrated using hybridization probes derived from the divergent 3' noncoding sequences of the two cDNAs . The differential expression suggests specialized roles for each variant in different tissues, potentially optimized for the specific metabolic demands of each tissue type.

This pattern aligns with observations in humans, where AAC1 (encoded by SLC25A4) is specific to the heart, skeletal muscle, and brain , suggesting conserved tissue-specific expression patterns across species.

What factors regulate the transcription and translation of bovine SLC25A4?

While the search results do not provide specific details on the transcriptional and translational regulation of bovine SLC25A4, we can infer potential regulatory mechanisms based on the available information:

• Tissue-Specific Transcription Factors: Given the differential expression in heart muscle versus intestine , tissue-specific transcription factors likely play a crucial role in regulating SLC25A4 expression.

• Metabolic Demand Sensing: As a critical component of energy metabolism, SLC25A4 expression is likely responsive to cellular energy demands and metabolic states.

• Post-Transcriptional Regulation: The extensive divergence in 3' noncoding sequences between the two bovine SLC25A4 variants suggests potential differences in post-transcriptional regulation, such as mRNA stability, localization, or translation efficiency.

• Epigenetic Regulation: Tissue-specific expression patterns may also be maintained through epigenetic mechanisms, including DNA methylation and histone modifications at the gene promoters.

Further research focused specifically on the regulatory elements controlling bovine SLC25A4 expression would be valuable for understanding how its expression is modulated in different physiological and pathological conditions.

How do isoform expression levels compensate for mutations in SLC25A4?

The search results provide insights into how alternative isoform expression can compensate for mutations in SLC25A4, particularly in the context of disease severity:

This compensatory mechanism involves:

• Wild-Type Allele Expression: In heterozygous mutations, the remaining wild-type allele continues to produce functional protein, providing partial compensation.

• Alternative Isoform Expression: Humans have four AAC isoforms, with AAC1 being specific to heart, skeletal muscle, and brain . Other isoforms (AAC2, AAC3, AAC4) expressed in these tissues may provide functional redundancy when AAC1 is impaired.

• Tissue-Specific Compensation: The effectiveness of compensation likely varies across tissues, potentially explaining why some mutations affect certain tissues more severely than others, leading to tissue-specific disease manifestations despite the mutation being present in all cells.

This compensatory mechanism helps explain the complex relationship between genotype and phenotype in SLC25A4-related diseases and highlights the importance of considering total carrier capacity rather than just the impact on the mutated protein.

What crystallization techniques have been successful for SLC25A4 structural studies?

The crystallization of mitochondrial carriers like SLC25A4 presents significant challenges due to their hydrophobic nature and conformational flexibility. Based on the search results, the following approaches have shown promise:

• State-Specific Inhibitor Stabilization: Using bongkrekic acid (BKA) to lock the carrier in the matrix state has facilitated successful crystallization . This approach stabilizes a specific conformation, reducing the conformational heterogeneity that often hinders crystallization.

• Detergent Selection: Maltose-neopentyl glycol detergents have proven effective in improving the stability of the detergent-solubilized protein during crystallization attempts .

• Vapor-Diffusion Techniques: Standard vapor-diffusion crystallization techniques have been employed successfully, though the resulting crystals were noted to be unstable, dissolving within days in the crystallization drops .

• Stability-Enhancing Mutations: Strategic mutations such as Q302K, which mimics the network residues found in human and bovine carriers, increased the thermal stability of the BKA-inhibited protein and may facilitate crystallization .

Despite these advances, the crystallization of SLC25A4 remains challenging, with issues of crystal stability and quality. Future approaches might benefit from the use of lipidic cubic phase crystallization, antibody-mediated crystallization, or cryo-electron microscopy as alternative structural determination methods.

How can researchers design assays to measure ADP/ATP exchange kinetics in recombinant SLC25A4?

Designing robust assays to measure ADP/ATP exchange kinetics is crucial for studying the functional impact of mutations and potential inhibitors. Based on the search results, the following methodological approach is recommended:

Reconstituted Transport Assay:

• Expression System: Express the recombinant SLC25A4 in a suitable system (e.g., L. lactis)

• Membrane Preparation: Prepare fused membrane vesicles containing the expressed protein

• Substrate Loading: Load the vesicles with ADP

• Transport Measurement: Measure the uptake of radiolabeled ADP in exchange for loaded ADP

• Inhibitor Control: Use specific inhibitors such as carboxyatractyloside as controls to confirm specificity

• Quantification: Quantify transport rates to determine kinetic parameters

Data Analysis for Kinetic Parameters:

• Determine initial rates at various substrate concentrations

• Calculate Km and Vmax values for substrate binding and transport

• Compare kinetic parameters between wild-type and mutant proteins

• Assess the impact of potential inhibitors on transport kinetics

This approach has been successfully used to demonstrate that mutations like p.Lys33Gln completely abolish transport activity despite normal protein expression , highlighting its utility for structure-function studies.

What are the best approaches for studying SLC25A4 interactions with potential inhibitors?

Studying interactions between SLC25A4 and potential inhibitors requires a multi-faceted approach that combines structural, biochemical, and functional analyses. Based on the search results, the following strategies are recommended:

• State-Specific Inhibitor Studies:

  • Bongkrekic acid (BKA) has been used successfully to lock the carrier in the matrix state

  • Carboxyatractyloside is another specific inhibitor that can be used as a control in transport assays

  • These state-specific inhibitors provide valuable tools for studying the conformational states of the carrier

• Structural Analysis of Inhibitor Binding:

  • X-ray crystallography of SLC25A4 in complex with inhibitors (as demonstrated with BKA) provides detailed insights into binding mechanisms

  • The recently solved structure of the matrix-open state in complex with BKA has revealed important aspects of the transport mechanism

• Functional Transport Assays:

  • Measure the inhibition of ADP/ATP exchange using the reconstituted transport assay described above

  • Determine IC50 values and inhibition kinetics to characterize inhibitor potency and mechanism

• Thermal Stability Assays:

  • Assess the impact of inhibitors on protein thermal stability

  • The Q302K mutation increased thermal stability of the BKA-inhibited protein , suggesting that thermal shift assays can provide insights into inhibitor binding

• Competition Binding Assays:

  • Use labeled inhibitors or substrates to study competitive binding

  • Determine whether novel inhibitors compete with known inhibitors or substrates

These approaches provide complementary information about inhibitor binding, mechanism of action, and effects on carrier conformation, facilitating the development of new tools for studying carrier function or potential therapeutic applications.

How does bovine SLC25A4 compare structurally and functionally to homologues in other species?

Comparison of bovine SLC25A4 with homologues in other species reveals both conservation and divergence:

• Sequence Conservation:

  • Thermothelomyces thermophila ADP/ATP carrier (TtAac) has 51% identity to the bovine ADP/ATP carrier

  • Saccharomyces cerevisiae Aac2 and Aac3 share 75% sequence identity with TtAac

  • The residue Lys33, which forms a salt bridge with Asp232 in the matrix network, is conserved among AAC from fungi, plants, and metazoans

• Structural Variations:

  • Fungal ADP/ATP carriers typically have an atypical glutamine (Q302) instead of a lysine residue on the C-terminal end of H6, resulting in a weaker cytoplasmic salt-bridge network compared to human and bovine carriers

  • The Q302K mutation in TtAac, which mimics the network residues found in human and bovine carriers, increased thermal stability of the BKA-inhibited protein

• Functional Conservation:

  • The basic transport mechanism involving alternating access between cytoplasmic and matrix states appears conserved across species

  • The role of salt bridge networks in the transport cycle is maintained, though with some species-specific variations

These comparisons highlight the evolutionary conservation of the core transport mechanism while revealing adaptations that may be related to species-specific metabolic requirements or environmental conditions.

What unique features distinguish SLC25A4 from other members of the mitochondrial carrier family?

SLC25A4 (ADP/ATP carrier) possesses several distinctive features that differentiate it from other members of the mitochondrial carrier family:

• Substrate Specificity: SLC25A4 specifically transports adenine nucleotides (ADP and ATP), as opposed to other carriers that transport amino acids, carboxylic acids, fatty acids, cofactors, or inorganic ions .

• Physiological Role: Its primary function in importing ADP into the mitochondrion and exporting ATP to the cytoplasm makes it central to cellular energy metabolism , giving it a particularly critical role compared to many other carriers.

• Tissue Expression Pattern: In humans, AAC1 (encoded by SLC25A4) shows tissue-specific expression in heart, skeletal muscle, and brain , reflecting its adaptation to tissues with high energy demands.

• Inhibitor Sensitivity: SLC25A4 is specifically inhibited by certain compounds like bongkrekic acid and carboxyatractyloside , which have been valuable tools in structural and functional studies.

• Disease Associations: Mutations in SLC25A4 are associated with a distinctive spectrum of human diseases, including progressive external ophthalmoplegia, cardiomyopathy, and skeletal myopathy , highlighting its critical physiological importance.

• Transport Mechanism: While all mitochondrial carriers share common structural features, the specific details of the transport mechanism, including the coordinated movement of six dynamic elements around a central translocation pathway , may have unique aspects in SLC25A4.

These distinguishing features reflect the specialized role of SLC25A4 in cellular energy metabolism and explain why it has been a focus of extensive research within the mitochondrial carrier family.

How do the transport kinetics differ between bovine SLC25A4 isoforms?

Given these differences in sequence and expression pattern, it is reasonable to hypothesize potential variations in transport kinetics between these isoforms, which might include:

• Substrate Affinity: Differences in Km values for ADP and ATP, potentially reflecting adaptation to tissue-specific metabolic demands.

• Transport Rate: Variations in Vmax that might correlate with the energy requirements of the tissues where each isoform predominates.

• Regulatory Sensitivity: Different responses to regulatory factors such as membrane potential, pH, or allosteric modulators.

• Inhibitor Sensitivity: Potentially different sensitivity profiles to inhibitors like bongkrekic acid or carboxyatractyloside.

Further research specifically comparing the kinetic properties of these bovine isoforms would be valuable for understanding how they are adapted to the metabolic requirements of different tissues. Such studies could employ the reconstituted transport assays described earlier to systematically compare kinetic parameters.

How do SLC25A4 mutations contribute to the pathophysiology of mitochondrial diseases?

SLC25A4 mutations contribute to mitochondrial disease pathophysiology through several mechanisms:

• Impaired Energy Production: The primary function of SLC25A4 is to import ADP into mitochondria for ATP synthesis and export ATP to fuel cellular activities . Mutations that disrupt this transport directly impact cellular energy production.

• Tissue-Specific Effects: The differential expression of ADP/ATP carrier isoforms across tissues helps explain why some mutations affect specific tissues while sparing others. The p.Lys33Gln mutation, for instance, causes a mild skeletal myopathy without affecting heart or brain function , despite SLC25A4 being expressed in all these tissues.

• Haploinsufficiency: Evidence suggests that haploinsufficiency is a plausible disease mechanism . When expression levels of the carrier decrease, growth rates also decrease, indicating that a reduction in carrier quantity directly impacts mitochondrial function.

• Compensatory Mechanisms: The severity of disease may be modulated by compensatory expression of wild-type alleles and alternative isoforms . The effectiveness of this compensation varies across tissues and with different mutations, contributing to phenotypic variability.

• Structural Disruption: Mutations like p.Lys33Gln disrupt critical structural elements such as salt bridges and the glutamine brace , impairing the transport mechanism and potentially affecting protein stability.

Understanding these pathophysiological mechanisms is crucial for developing targeted therapeutic approaches for SLC25A4-related diseases.

What therapeutic approaches target SLC25A4 dysfunction in mitochondrial disorders?

These approaches would need to be tailored to the specific mutation and disease phenotype, considering factors such as whether the mutation causes loss of function, dominant negative effects, or haploinsufficiency.

How can animal models advance our understanding of SLC25A4-related disorders?

Animal models can significantly advance our understanding of SLC25A4-related disorders by providing insights into disease mechanisms, progression, and potential therapeutic approaches. Based on the available information, several approaches to animal modeling would be valuable:

• Knockout and Knockin Models:

  • Heterozygous knockout models to study haploinsufficiency, which has been proposed as a disease mechanism

  • Knockin models of specific mutations like p.Lys33Gln to recapitulate human disease phenotypes

  • Tissue-specific conditional knockouts to understand the differential effects on various tissues

• Expression Studies:

  • Models with differential expression of SLC25A4 variants to study tissue-specific effects

  • Leveraging the observation that different bovine SLC25A4 genes show tissue-specific expression patterns

• Compensatory Mechanism Investigation:

  • Models that allow manipulation of alternative AAC isoform expression

  • This could help understand how compensatory expression of wild-type alleles and other isoforms modulates disease severity

• Therapeutic Testing:

  • Evaluation of gene therapy, small molecule, or metabolic bypass approaches

  • Assessment of the efficacy of upregulating compensatory isoforms

• Developmental Studies:

  • Models allowing the study of temporal aspects of disease progression

  • Investigation of developmental windows for therapeutic intervention

These animal models would provide valuable tools for understanding disease mechanisms, identifying biomarkers, and developing and testing potential therapeutic strategies for SLC25A4-related disorders.

What emerging technologies could advance SLC25A4 research?

Several emerging technologies hold promise for advancing SLC25A4 research:

• Cryo-Electron Microscopy (Cryo-EM):

  • Given the challenges in crystallizing SLC25A4, as evidenced by unstable crystals that dissolved within days , cryo-EM could provide an alternative approach for structural determination

  • This technique might capture additional conformational states beyond the cytoplasmic and matrix states currently known

• Single-Molecule Transport Assays:

  • Development of techniques to observe ADP/ATP exchange at the single-molecule level

  • This could provide unprecedented insights into the dynamics and heterogeneity of transport activity

• Genome Editing Technologies:

  • CRISPR-Cas9 approaches for creating precise disease models

  • Base editing or prime editing for correcting pathogenic mutations in cellular models

• Advanced Imaging Techniques:

  • Super-resolution microscopy to study the spatial organization of SLC25A4 in mitochondrial membranes

  • Live-cell imaging of carrier dynamics using fluorescently tagged variants

• Computational Approaches:

  • Molecular dynamics simulations to study the conformational changes during the transport cycle

  • Machine learning approaches to predict the impact of novel mutations on carrier function

• High-Throughput Functional Assays:

  • Development of scalable assays for measuring ADP/ATP transport

  • Screening platforms for identifying small molecule modulators of carrier function

These technologies could address current knowledge gaps and accelerate the translation of basic science findings into clinical applications.

What are the key unresolved questions in SLC25A4 biology?

Despite significant advances, several crucial questions about SLC25A4 biology remain unresolved:

• Detailed Transport Mechanism:

  • While structural studies have revealed conformational changes between cytoplasmic and matrix states , the precise sequence and energetics of these changes during transport remain to be fully elucidated

• Regulatory Mechanisms:

  • How is SLC25A4 activity regulated in response to cellular energy demands?

  • What post-translational modifications affect carrier function?

• Tissue-Specific Expression Control:

  • What factors control the differential expression of SLC25A4 variants across tissues ?

  • How is this regulation altered in disease states?

• Compensatory Mechanisms:

  • How do alternative AAC isoforms compensate for SLC25A4 dysfunction ?

  • Can these compensatory mechanisms be therapeutically enhanced?

• Interaction with Other Mitochondrial Proteins:

  • Does SLC25A4 function as part of larger protein complexes in vivo?

  • How does it interact with other components of the oxidative phosphorylation system?

• Evolution of Tissue-Specific Isoforms:

  • What selective pressures drove the evolution of tissue-specific SLC25A4 variants ?

  • How do these variants optimize for tissue-specific metabolic demands?

Addressing these questions will require integrated approaches combining structural biology, biochemistry, genetics, and systems biology perspectives.

How might systems biology approaches integrate SLC25A4 function into broader mitochondrial networks?

Systems biology approaches offer powerful frameworks for understanding how SLC25A4 functions within the broader context of mitochondrial and cellular metabolic networks:

These systems-level approaches could reveal emergent properties not apparent from reductionist studies and identify novel therapeutic targets within mitochondrial networks affected by SLC25A4 dysfunction.