NACA Human
Description
Fundamental Characteristics of NACA
NACA is a modified form of N-acetylcysteine (NAC), distinguished by the neutralization of the carboxyl group to form an amide. This structural modification significantly enhances its hydrophobicity and membrane permeability compared to NAC . NACA, also referred to as AD4 in some research contexts, contains thiol and amine functional groups that serve as crucial chelation sites for divalent metal ions .
Chemical Structure and Properties
NACA exhibits the following chemical and physical characteristics:
| Property | Value |
|---|---|
| Molecular Formula | C₅H₁₀N₂O₂S |
| Molecular Weight | 162.21 Da |
| SMILES | CC(=O)NC@@HC(N)=O |
| InChIKey | UJCHIZDEQZMODR-BYPYZUCNSA-N |
| Physical Appearance | Sterile filtered colorless solution |
| Defined Stereocenters | 1/1 |
| Charge | 0 |
The human recombinant form of NACA produced in E. coli is a single, non-glycosylated polypeptide chain containing 235 amino acids (with a 20-amino acid His-tag at the N-terminus) and has a molecular mass of 25.5 kDa .
Stability and Formulation
In commercial preparations, NACA solution (1mg/ml) typically contains 20mM Tris-HCl buffer (pH 8.0), 0.15M NaCl, 1mM DTT, and 10% glycerol . For storage purposes, it is recommended to:
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Store at 4°C if the entire vial will be used within 2-4 weeks
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Store frozen at -20°C for longer periods
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Add a carrier protein (0.1% HSA or BSA) for long-term storage
Mechanistic Action and Antioxidant Properties
NACA's primary mechanism of action centers on its enhanced antioxidant capabilities and its role as a precursor to glutathione (GSH), the most abundant endogenous antioxidant in the human body .
Comparative Antioxidant Efficacy
Research has demonstrated that NACA possesses superior antioxidant properties compared to its parent compound NAC in several key parameters:
These findings provide compelling evidence that NACA has indeed enhanced the antioxidant properties of NAC, making it a promising candidate for therapeutic applications requiring potent antioxidant activity .
Metal Chelation Properties
NACA demonstrates significant metal chelation capabilities, particularly with heavy metals such as lead (Pb). Research comparing the chelation properties of NAC and NACA with Pb(II) revealed:
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NACA has a higher binding affinity for Pb(II) than NAC as demonstrated by HPLC data showing less free Pb(II) in solution after complexation with NACA
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X-ray photoelectron spectroscopy (XPS) analysis confirmed that more Pb(II) was chemically bound to NACA than NAC
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The isoelectric point of NACA (PZC = 5.1) is closer to cytoplasm pH (7.2-7.4) than that of NAC (PZC = 2.0), making NACA more amenable to traversing cell membranes
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Density functional theory (DFT) calculations supported a greater interaction energy of Pb(II) with NACA than NAC
These properties suggest that NACA may be more effective than NAC for treating metal poisoning, particularly for intracellular metals due to its enhanced membrane permeability .
Therapeutic Applications and Clinical Evidence
NACA has demonstrated therapeutic potential across multiple medical applications, with particularly promising results in neuroprotection and traumatic brain injury treatment.
Neuroprotection and Traumatic Brain Injury
Systematic reviews of human and animal studies have revealed significant neuroprotective effects of NACA following traumatic brain injury (TBI):
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Animal studies demonstrated substantial improvement in cognition and psychomotor performance following NACA administration post-TBI
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Research showed significantly more cortical sparing, reduced apoptosis, and lower levels of biomarkers of inflammation and oxidative stress with NACA treatment
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Two randomized controlled trials (RCTs) in humans reported improvement in functional outcomes after NAC/NACA administration
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No safety concerns were reported in any of the studies, suggesting a favorable safety profile
The evidence supports NACA's prophylactic application post-TBI with improved neurofunctional outcomes and downregulation of inflammatory and oxidative stress markers at the tissue level .
Heavy Metal Chelation
NACA's enhanced metal chelation properties make it particularly valuable for treating heavy metal poisoning:
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NACA demonstrated greater binding affinity for lead (Pb) than NAC and cysteamine in experimental studies
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The hydrophobic nature of NACA allows it to cross the blood-brain barrier, unlike NAC, making it potentially effective for treating intracellular metal toxicity in the central nervous system
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NACA's isoelectric point (PZC = 5.1) being closer to physiological pH enhances its ability to function effectively in biological systems
Other Therapeutic Applications
Research has indicated potential benefits of NACA in various other medical applications:
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Potential effectiveness in slowing nigral neuronal degeneration in Parkinson's disease
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Protection against allergic airway disease through regulation of NF-κB activation
Comparative Analysis: NACA vs. NAC
A direct comparison between NACA and its parent compound NAC reveals several key advantages that contribute to NACA's enhanced therapeutic potential:
These comparative advantages highlight why NACA represents a significant advancement over NAC for therapeutic applications requiring enhanced membrane penetration and antioxidant activity .
In Vivo Application Guidelines
For experimental traumatic brain injury models, the following administration protocol has been documented:
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Dosage: 75, 150, 300, or 600 mg/kg body weight
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Timing: 15 minutes and 6 hours post-injury
In Vitro Application Guidelines
For cellular studies, particularly with neuroblastoma cells:
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Concentration range: 0.05-2 mM NACA
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Experimental conditions: Co-treatment with neurotoxins such as levodopa (0.06 mM), dopamine (0.06 mM), 6-OHDA (0.06 mM), or MPP+ (1.5 mM)
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Observed effects: 20-50% increase in survival rates in a dose-dependent manner (P < 0.05)
Current Research Limitations and Future Directions
Despite promising results, several limitations exist in the current research landscape for NACA:
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Limited number of well-designed human clinical trials, with only three human trials documented in systematic reviews
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Need for standardized protocols for NACA administration in different clinical contexts
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Limited long-term safety data for chronic administration
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Incomplete understanding of all potential therapeutic applications
Future research directions should focus on:
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Conducting larger, well-designed randomized controlled trials in humans
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Investigating optimal dosing regimens for different therapeutic applications
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Examining potential synergistic effects with other therapeutic agents
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Expanding research into additional oxidative stress-related conditions
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Developing improved delivery systems for targeted NACA delivery
Distinction from NACA Protein/Gene
It is important to note that "NACA" also refers to the Nascent polypeptide-associated complex alpha subunit, a protein encoded by the NACA gene in humans . This protein is distinct from the N-acetylcysteine amide compound discussed in this article. The NACA protein:
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Functions to prevent inappropriate targeting of non-secretory polypeptides to the endoplasmic reticulum
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Binds to nascent polypeptide chains as they emerge from ribosomes
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Has been shown to interact with BTF3, FADD, C-jun, and members of the taxilin family
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May act as a specific coactivator for JUN, binding to DNA and stabilizing the interaction of JUN homodimers with target gene promoters
This distinction is crucial when researching "NACA Human" to ensure appropriate contextualization of scientific findings.
Product Specs
Q&A
What is NACA and how does it differ structurally from NAC?
NACA (N-Acetylcysteine Amide) is a modified form of NAC (N-acetylcysteine) containing an amide group instead of a carboxyl group. This structural modification was specifically designed to neutralize the carboxyl group to enhance its ability to pass through cell membranes . The amide substitution increases NACA's lipophilicity, potentially improving its bioavailability and cellular penetration compared to NAC, particularly in crossing biological barriers such as the blood-brain barrier .
What are the primary research applications of NACA in human studies?
NACA has been investigated across multiple research domains including neuroscience, hematology, and oxidative stress modulation. Key research applications include: (1) neuroprotection in conditions involving blood-brain barrier disruption, (2) modulation of erythroid cell differentiation, (3) protection against ischemia-reperfusion injury, and (4) reduction of oxidative stress in various tissues . Research models range from in vitro human stem cell-derived systems to animal models that simulate human pathological conditions.
How are human stem cell models utilized to test NACA efficacy at the blood-brain barrier?
Researchers have developed sophisticated "brain-on-chip" experimental models using human stem cell-derived cells to simulate the blood-brain barrier. These models typically employ a two-layered setup with channels that carry simulated blood, inflammation agents, and anti-inflammatory drugs through compartments representing both the perivascular space within the brain and the external vascular system . The barrier between these compartments consists of cells that mimic the blood-brain barrier's tight junctions. This model allows minute-by-minute monitoring of how the barrier responds to inflammatory challenges and NACA administration, providing dynamic data that would be impossible to obtain in vivo .
What are the methodological considerations when designing human cell experiments with NACA?
When designing experiments involving NACA in human cell models, researchers should consider:
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Cell source specificity: Human stem cell-derived models provide greater translational relevance than animal-derived cells .
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Dosage determination: Concentration-response studies should precede main experiments.
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Timing protocols: For inflammation studies, pre-treatment, co-treatment, and post-treatment protocols may yield different insights.
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Appropriate controls: Both negative controls and NAC-treated positive controls should be included for comparative efficacy assessment.
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Measurement parameters: Multiple endpoints should be assessed, including barrier integrity, inflammatory marker expression, and oxidative stress indicators .
How does NACA modulate oxidative stress in human tissues?
NACA functions as a potent antioxidant through multiple mechanisms. As a free radical scavenger, it directly neutralizes reactive oxygen species. Additionally, NACA serves as a precursor for glutathione synthesis, replenishing intracellular glutathione levels that are critical for cellular redox balance . In human tissue models, NACA has demonstrated superior antioxidant capacity compared to NAC, particularly in conditions of ischemia-reperfusion where the total antioxidative status was significantly higher and total oxidative status lower in NACA-treated samples . This dual action of direct scavenging and glutathione enhancement makes NACA particularly effective in conditions of acute oxidative stress.
What is the role of NACA in human erythroid cell differentiation?
Research indicates that NACA functions as a positive regulator in human erythroid cell differentiation. Protein distribution analyses show that NACA is expressed in undifferentiated TF-1 cells and in human cord-blood-derived CD34+ progenitor cells . Importantly, this expression is maintained throughout erythroid differentiation but is suppressed during megakaryocytic or granulocytic differentiation pathways . Ectopic expression experiments demonstrate that NACA can significantly accelerate erythroid-lineage differentiation when introduced into CD34+ cells under appropriate culture conditions . This suggests NACA has lineage-specific regulatory functions in hematopoiesis.
How can researchers optimize experimental design when studying NACA's effects on the blood-brain barrier?
Optimizing experimental design for blood-brain barrier studies requires careful consideration of multiple variables. Researchers should:
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Enhance the signal-to-noise ratio by controlling for confounding variables that may mask NACA's effects .
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Implement standardized methodology following APA guidelines for experiments with human participants or human-derived materials .
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Clearly identify independent variables (e.g., NACA concentration, exposure duration) and dependent variables (e.g., barrier permeability, inflammatory marker expression) .
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Consider time-course experiments to capture both immediate and delayed effects of NACA on barrier function.
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Employ both functional and molecular readouts to comprehensively assess barrier integrity before and after NACA treatment .
How do the therapeutic effects of NACA compare to NAC in human-relevant models?
The comparative efficacy of NACA versus NAC has been evaluated in several experimental models relevant to human conditions. Below is a comparison table based on research findings:
What methodological differences should researchers consider when transitioning from NAC to NACA studies?
Researchers transitioning from NAC to NACA studies should consider several methodological adjustments:
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Dosage equivalence: Due to NACA's potentially greater bioavailability, dose-response studies should be conducted rather than assuming equivalent dosing to NAC.
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Timing protocols: NACA's enhanced membrane permeability may alter optimal administration timing.
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Biomarker selection: Additional biomarkers of cellular penetration may be relevant for NACA studies.
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Model selection: Models specifically designed to evaluate barrier penetration (like the blood-brain barrier) become more relevant with NACA.
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Delivery methods: Different formulation or delivery systems may be optimal for NACA compared to NAC.
How can NACA be utilized in human neural tissue protection studies?
NACA shows promise for neural tissue protection through several mechanisms. Researchers can utilize this compound in:
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Blood-brain barrier integrity studies: NACA has demonstrated protective effects against inflammation-induced barrier breakdown in human stem cell models .
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Oxidative stress protection: NACA can be applied in models of neural oxidative damage to evaluate its protective capacity.
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Neurodegenerative disease models: Given its antioxidant properties, NACA may be valuable in models of conditions like Alzheimer's and Parkinson's diseases where oxidative stress plays a pathogenic role .
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Traumatic brain injury research: NACA's neuroprotective capacity can be evaluated in models simulating traumatic brain injury.
When designing such studies, researchers should implement comprehensive readouts including molecular markers of oxidative stress, inflammatory mediators, and functional assessments of neural activity.
What is the significance of NACA's nucleic acid-binding capability in research applications?
The discovery that NACA contains a nucleic acid-binding region opens new research directions . This capability suggests that NACA may play roles in:
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Transcriptional regulation: NACA may directly influence gene expression patterns.
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mRNA stabilization or processing: The nucleic acid binding capacity could affect post-transcriptional processes.
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Chromatin interactions: NACA might participate in chromatin remodeling or accessibility.
Researchers can design experiments to investigate these possibilities using techniques such as:
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Chromatin immunoprecipitation (ChIP) assays to identify NACA-DNA interactions
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RNA immunoprecipitation to identify NACA-RNA interactions
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Gene expression analyses following NACA modulation
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Structure-function studies using mutated NACA lacking the nucleic acid-binding region
How should researchers address variability in NACA experimental outcomes?
Addressing variability in NACA experimental outcomes requires systematic approaches to experimental design and analysis:
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Implement rigorous standardization of protocols, including preparation, storage, and administration of NACA.
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Follow standardized ethics approval procedures for human-derived materials .
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Conduct power analyses to determine appropriate sample sizes for detecting expected effect sizes.
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Minimize noise factors by controlling experimental conditions and identifying potential confounding variables .
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Consider individual variability in response to NACA by increasing biological replicates and potentially stratifying analyses.
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Employ appropriate statistical methods that account for the distribution characteristics of the data and multiple comparisons.
What are the key considerations for translating NACA findings from experimental models to human applications?
Translational considerations for NACA research include:
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Model relevance: Prioritize human cell-derived models over animal models where possible for greater translational validity .
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Dosage scaling: Develop appropriate algorithms for scaling experimental doses to potential human applications.
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Pharmacokinetic differences: Account for species-specific differences in NACA metabolism and distribution.
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Target tissue accessibility: Consider barriers to NACA delivery that exist in intact human systems but may be absent in simplified models.
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Duration effects: Evaluate both acute and chronic administration effects, as clinical applications may require extended treatment protocols.
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Combination effects: Assess potential interactions with other medications or treatments likely to be co-administered in clinical settings.
What emerging techniques could enhance NACA human research?
Emerging techniques that could advance NACA research include:
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Organ-on-chip technologies: More sophisticated multi-organ systems that capture complex physiological interactions relevant to NACA action .
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Single-cell analysis: Techniques to evaluate cell-specific responses to NACA within heterogeneous tissues.
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In vivo imaging: Non-invasive methods to track NACA distribution and effects in living systems.
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-omics approaches: Multi-omics integration (genomics, proteomics, metabolomics) to comprehensively assess NACA's effects on cellular systems.
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AI-assisted experimental design: Machine learning approaches to optimize experimental conditions and predict outcomes.
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CRISPR-mediated target validation: Precise genetic manipulation to validate proposed mechanisms of NACA action.
How might researchers expand the applications of NACA beyond current domains?
Based on its mechanisms and current research, NACA could be explored in:
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Inflammatory disorders: Given its effects on oxidative stress and the blood-brain barrier, NACA could be investigated in systemic inflammatory conditions.
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Aging research: NACA's antioxidant properties may have applications in age-related oxidative damage models.
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Cancer research: The role of NACA in cell differentiation suggests potential applications in cancer differentiation therapy approaches .
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Metabolic disorder models: Oxidative stress plays a role in metabolic conditions, offering another potential application area.
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Regenerative medicine: NACA's effects on erythroid differentiation suggest potential applications in directed differentiation protocols for stem cells .
Product Science Overview
The Nascent Polypeptide-Associated Complex Alpha (NACA) is a crucial protein in humans, encoded by the NACA gene. This protein plays a significant role in the early stages of protein synthesis, ensuring that newly synthesized polypeptides are correctly processed and transported within the cell.
The NACA gene is located on chromosome 12 in humans . The protein encoded by this gene is part of the nascent polypeptide-associated complex (NAC), which is composed of two subunits: alpha (NACA) and beta. The alpha subunit is responsible for binding nascent polypeptide chains as they emerge from the ribosome .
NACA prevents inappropriate interactions between nascent polypeptides and cytosolic proteins by binding to the emerging polypeptide chains . This binding blocks the interaction with the signal recognition particle (SRP), which normally targets nascent secretory peptides to the endoplasmic reticulum (ER) . By doing so, NACA ensures that only proteins with signal peptides are directed to the ER, while others remain in the cytosol .
NACA plays a vital role in maintaining protein homeostasis within the cell. It prevents the mislocalization of non-secretory proteins to the ER, which could lead to cellular stress and dysfunction . Additionally, NACA is involved in various cellular processes, including transcription regulation, protein transport, and skeletal muscle development .
Recent studies have highlighted the importance of NACA in preventing the formation of protein aggregates, which are associated with neurodegenerative diseases such as Alzheimer’s and Huntington’s . Understanding the function of NACA and its role in protein quality control can provide insights into the development of therapeutic strategies for these diseases.
