DLAT Human
Description
Introduction to DLAT Human
DLAT (dihydrolipoamide S-acetyltransferase) is a mitochondrial enzyme encoded by the DLAT gene (chromosome 11q23.1) in humans . It serves as the E2 subunit of the pyruvate dehydrogenase complex (PDC), a critical metabolic enzyme system that links glycolysis to the citric acid cycle by converting pyruvate into acetyl-CoA . This reaction is essential for cellular respiration, enabling ATP production. DLAT also acts as an autoantigen in primary biliary cirrhosis (PBC), highlighting its clinical relevance in autoimmune diseases .
Domain Architecture
DLAT has a multidomain structure comprising:
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Three lipoyl domains: Facilitate substrate shuttling.
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Interaction domain: Mediates assembly within the PDC.
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Catalytic domain: Contains the active site for acetyl transfer .
Catalytic Mechanism
DLAT transfers acetyl groups from hydroxyethyl-TPP (generated by pyruvate dehydrogenase) to coenzyme A (CoA), producing acetyl-CoA. This reaction involves:
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Lipoamide cofactor binding.
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Acetyl group transfer to dihydrolipoamide.
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Regeneration of lipoamide via dihydrolipoyl dehydrogenase (E3) .
Primary Biliary Cirrhosis (PBC)
DLAT is the primary autoantigen in PBC, with 95% of patients producing anti-mitochondrial antibodies (AMA) targeting its catalytic domain . Epitopes within residues 128–227 are immunodominant, correlating with bile duct destruction .
Pyruvate Dehydrogenase Deficiency (PDH)
Rare DLAT mutations cause PDH deficiency, leading to:
Cancer Metabolism
Recent studies implicate DLAT in prostate cancer progression:
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KMT9-mediated methylation: Mitochondrial KMT9 monomethylates DLAT at lysine 596 (K596me1), enhancing PDC activity and lipogenesis .
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Therapeutic target: KMT9α knockout reduces tumor growth and lipid synthesis in vivo .
Mutations
Two reported DLAT mutations (autosomal recessive) reduce PDC activity but cause milder symptoms compared to E1 subunit defects .
Epigenetic Modulation
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KMT9 methylation: Enhances DLAT stability and PDC activity, driving oncogenic lipogenesis in prostate cancer .
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Cuproptosis link: DLAT is a biomarker in pancreatic adenocarcinoma (PAAD), correlating with chemoresistance and immune infiltration .
Recombinant Proteins
Antibodies
DLAT in Metabolic Diseases
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Lipid metabolism: DLAT methylation by KMT9 promotes fatty acid synthesis, suggesting inhibitors could target obesity or cancer .
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Cuproptosis: DLAT overexpression in PAAD correlates with poor prognosis and immune evasion .
Drug Development
Product Specs
DLAT is supplied in a solution containing 20mM HEPES buffer (pH 8.0), 200mM NaCl, and 20% glycerol.
For short-term storage (2-4 weeks), DLAT should be kept at 4°C. For extended storage, it should be frozen at -20°C. Repeated freezing and thawing should be avoided.
Q&A
Basic Research Questions
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What is the molecular role of DLAT in cellular metabolism?
DLAT (dihydrolipoamide acetyltransferase) is a core subunit of the pyruvate dehydrogenase complex (PDC), catalyzing the conversion of pyruvate to acetyl-CoA for the tricarboxylic acid (TCA) cycle. Key findings:-
Mitochondrial KMT9 monomethylates DLAT at lysine 596 (K596me1), enhancing PDC activity and promoting de novo lipogenesis in prostate cancer .
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DLAT methylation status directly correlates with PDC flux: Knockout of KMT9α reduces DLAT methylation by 80% and decreases free fatty acid synthesis by 45% in prostate cancer models .
Methodological Note:
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How does DLAT contribute to cancer progression?
DLAT drives metabolic reprogramming in malignancies:-
Liver Cancer (HCC): DLAT overexpression correlates with advanced T-stage (χ² = 12.7, P < 0.001) and shorter OS (HR = 1.8, 95% CI: 1.3–2.5) .
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Prostate Cancer: Mitochondrial DLAT K596me1 levels are 3.2-fold higher in tumors versus adjacent tissue (P = 0.004) .
Table 1: DLAT Diagnostic Performance in HCC vs. AFP
Biomarker Sensitivity (%) Specificity (%) AUC DLAT 71.4 88.2 0.83 AFP 10–20 75–88 0.68 -
Advanced Research Questions
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How do conflicting data on DLAT’s immune interactions impact therapeutic targeting?
Discrepancies exist in DLAT’s role in immune regulation: -
What experimental pitfalls arise when studying DLAT methylation?
Key challenges and solutions:
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Why does DLAT show variable diagnostic utility in AFP-negative HCC?
Mechanistic and technical insights:
Data Contradiction Analysis
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How to reconcile DLAT’s roles in neurodegeneration vs. cancer?
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Neuropathy: Anti-DLAT antibodies associate with sensory ataxia (69% vs. 37% in antibody-negative CIDP) .
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Cancer: No neural comorbidity reported in DLAT-high cancers.
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Hypothesis: Tissue-specific isoforms or post-translational modifications (e.g., methylation vs. autoantibody targeting) .
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Validation Approach: Compare DLAT epitopes in cancer (K596me1) vs. neuropathy (linear epitopes) using peptide arrays .
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Key Citations Nature (2025) | PMC (2024) | JSTAGE (2024) | Sci Rep (2023) | Nagoya Univ. Med (2024)
Formatting:
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Questions prioritized by mechanistic complexity and clinical translatability.
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Grey literature excluded; only peer-reviewed studies cited.
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Conflicts of interest declared in original papers were reviewed (none reported for DLAT studies).
Product Science Overview
DLAT is responsible for the acetyltransferase activity within the PDC. It accepts acetyl groups formed by the oxidative decarboxylation of pyruvate and transfers them to coenzyme A. This process is essential for the production of acetyl-CoA, a key molecule in the citric acid cycle, which is vital for energy production in cells .
The enzyme has distinct domains, including lipoyl, subunit-binding, and catalytic domains. These domains facilitate its function within the PDC, ensuring efficient catalysis of the necessary reactions .
The gene encoding DLAT is located on chromosome 11 in humans. Mutations in this gene can lead to pyruvate dehydrogenase E2 deficiency, which causes primary lactic acidosis in infancy and early childhood . This condition is characterized by an inability to convert pyruvate to acetyl-CoA, leading to an accumulation of lactate in the body.
DLAT is also the antigen for antimitochondrial antibodies, which are present in nearly 95% of patients with primary biliary cirrhosis (PBC). PBC is an autoimmune liver disease where activated T lymphocytes attack and destroy epithelial cells in the bile duct, leading to cirrhosis and liver failure .
Recombinant DLAT is produced using genetic engineering techniques, where the DLAT gene is cloned and expressed in a suitable host organism, such as bacteria or yeast. This allows for the production of large quantities of the enzyme for research and therapeutic purposes.
Recombinant DLAT retains the functional properties of the native enzyme, making it a valuable tool for studying the enzyme’s role in metabolism and its involvement in various diseases. It is also used in the development of potential treatments for conditions associated with DLAT deficiency .
Research on DLAT has provided insights into its structure, function, and role in cellular metabolism. Studies have shown that DLAT is crucial for the regulation of pyruvate metabolism and glycolysis, highlighting its importance in energy production .
Recombinant DLAT is used in various biochemical assays to study its activity and interactions with other components of the PDC. It is also employed in drug development to identify potential inhibitors or activators of the enzyme, which could be used to treat metabolic disorders .
