ACOT11 Human

What is ACOT11 and what is its genomic organization?

ACOT11, also known as StAR-related lipid transfer protein 14 (STARD14), is an enzyme encoded by the ACOT11 gene in humans. The gene is located on chromosome 1p32.3 and contains 18 exons . The protein encoded contains 258 amino acids and forms a homodimer with another chain. Its theoretical weight is 26.67 kDa . The protein is a member of the acyl-CoA thioesterase family that catalyzes the hydrolysis of various Coenzyme A esters to free acids plus CoA .

What domains are present in the ACOT11 protein and how do they function?

ACOT11 contains a StAR-related lipid transfer domain, which is responsible for binding to lipids . This domain enables its acyl-CoA thioesterase activity toward medium (C12) and long-chain (C18) fatty acyl-CoA substrates . The protein has four known ligands that bind to its homodimer structure: polyethylene glycol, chlorine, glycerol, and a form of TCEP . The StAR-related transfer domain is critical for the protein's function in lipid metabolism and potentially its role in disease states.

What is the basic reaction catalyzed by ACOT11?

ACOT11, as part of the ACOT family, catalyzes the following hydrolysis reaction:
CoA ester + H2O → free acid + coenzyme A

This enzymatic activity distinguishes ACOTs from long-chain acyl-CoA synthetases, which perform the opposite reaction (ligating fatty acids to CoA) . Through this hydrolysis activity, ACOT11 potentially regulates intracellular levels of CoA esters, Coenzyme A, and free fatty acids, which are crucial for numerous cellular processes .

How does ACOT11 contribute to lipid metabolism regulation?

ACOT11 regulates intracellular levels of fatty acyl-CoA esters, which serve as more than just energy sources in cellular metabolism . By hydrolyzing these CoA esters, ACOT11 can influence multiple metabolic pathways. Fatty acyl-CoAs participate in allosteric regulation of enzymes including acetyl-CoA carboxylase, hexokinase IV, and the citrate condensing enzyme . Additionally, long-chain acyl-CoAs regulate ATP-sensitive potassium channels and calcium ATPases, thereby affecting insulin secretion . Through modulation of these fatty acid intermediates, ACOT11 likely serves as a metabolic checkpoint in lipid homeostasis.

What metabolic processes might be influenced by ACOT11 activity?

ACOT11's enzymatic activity potentially influences several key metabolic processes:

• Regulation of signal transduction through protein kinase C

• Modulation of retinoic acid-induced apoptosis

• Involvement in endomembrane system budding and fusion

• Regulation of protein targeting to various membranes

• Modulation of G protein α subunits via substrates for protein acylation

• Regulation of mitochondrial NAD+-dependent dehydrogenases through acylation, affecting amino acid catabolism

These diverse roles suggest ACOT11 might serve as a metabolic regulator at the intersection of lipid metabolism and numerous other cellular processes.

How is ACOT11 expression regulated in response to environmental factors?

Research in murine models indicates that ACOT11 expression in brown adipose tissue is induced by cold exposure and repressed by warmth . This temperature-dependent regulation suggests a potential role in thermogenesis. Additionally, expression patterns differ between obesity-resistant and obesity-prone mice, with higher expression observed in obesity-resistant mice . These findings indicate ACOT11 may function as an adaptive metabolic regulator responsive to environmental stressors.

What is the clinical profile of ACOT11 in cancer tissues?

Studies have shown high expression of ACOT11 in tumor samples compared to normal tissues . Particularly in lung squamous carcinoma (LUSC) patients, high ACOT11 expression correlates significantly with poor prognosis . Clinical data analysis from TCGA database (576 LUAD and 552 LUSC samples) confirmed this correlation . This expression pattern suggests ACOT11 may serve as a prognostic biomarker for certain types of lung cancer.

How does ACOT11 influence cancer cell behavior?

Experimental evidence demonstrates that ACOT11 promotes cell proliferation, migration, and invasion in lung cancer cells . Knockdown of ACOT11 inhibits these processes both in vitro and in vivo . Additionally, ACOT11 knockdown promotes cell apoptosis and cell cycle arrest via multiple signaling pathways . These effects suggest ACOT11 functions as an oncogenic driver in lung carcinoma, potentially through its influence on lipid metabolism and associated signaling pathways.

What proteins interact with ACOT11 in cancer-related processes?

Immunoprecipitation studies have identified that ACOT11 binds with CSE1L, which is a confirmed oncogene in lung cancer . This interaction suggests CSE1L might be a potential target of ACOT11 in cancer progression . Further proteomic analysis revealed an extensive interactome of 573 proteins that interact with ACOT11 , indicating its involvement in complex regulatory networks. These protein-protein interactions likely contribute to ACOT11's role in cancer pathogenesis.

What cell models are appropriate for ACOT11 functional studies?

Based on reported research protocols, lung carcinoma cell lines A549 and NCI-H1975 have been successfully used for ACOT11 studies . These cell lines exhibit moderate ACOT11 expression levels, making them suitable for both gene silencing and overexpression experiments . Cells should be cultured at 37°C in Dulbecco's modified Eagle's medium (DMEM) containing 10% fetal bovine serum, 100 units/mL penicillin, and 100 mg/mL streptomycin in a humidified atmosphere of 5% CO2 .

What methods are effective for ACOT11 knockdown in experimental models?

Lentiviral vector-based RNA interference has proven effective for ACOT11 knockdown. The methodology involves:

• Designing shRNAs targeting ACOT11 (e.g., target sequence: TTGTCTATGCAGACACCAT)

• Packaging lentiviral vectors carrying these shRNAs (and often EGFP under CMV promoter control)

• Infecting cells at a multiplicity of infection (MOI) of 10

• Transducing cells for 72 hours

• Selecting transductants with puromycin (2.5 μg/mL) for 48 hours

• Confirming knockdown efficiency via microscopy and molecular techniques

This approach provides stable ACOT11 knockdown for both in vitro and in vivo experiments.

How can ACOT11 protein interactions be studied experimentally?

Co-immunoprecipitation (Co-IP) has been successfully employed to examine interactions between ACOT11 and potential partner proteins:

• Overexpress 3X Flag-ACOT11 in appropriate cell lines (e.g., A549)

• Use flag antibody for immunoprecipitation

• Detect interacting proteins via Western blot

• For more comprehensive interaction profiling, combine with mass spectrometry

This approach has successfully identified interactions such as that between ACOT11 and CSE1L, providing insights into ACOT11's functional mechanisms.

What is the correlation between ACOT11 expression and clinical features in cancer patients?

Clinical data analysis reveals relationships between ACOT11 expression and patient characteristics. A study of 139 lung cancer patients showed the following distribution:

How can ACOT11 expression be assessed in clinical samples?

Immunohistochemistry (IHC) is an effective method for assessing ACOT11 expression in clinical samples. The protocol involves:

• Preparing tissue microarray (TMA) slides containing paired cancer and normal tissue samples

• Hybridizing with primary antibody against ACOT11 (1:50; Rabbit anti-Human, SIGMA)

• Capturing images with microscope and processing using appropriate software (e.g., Nano Zoomer Digital Pathology View)

• Having independent pathologists assess the immunohistochemical score while blinded to clinical data

• Statistical analysis to determine significance of expression differences

This methodology allows for reliable assessment of ACOT11 protein levels in patient samples.

What are the knowledge gaps in ACOT11 research that need addressing?

While significant progress has been made in understanding ACOT11's role in cancer, several knowledge gaps remain:

• The precise molecular mechanisms by which ACOT11 promotes cancer cell proliferation and invasion

• The full spectrum of signaling pathways influenced by ACOT11 activity

• The significance of the 573 proteins identified in ACOT11's interactome

• The therapeutic potential of targeting ACOT11 in cancer treatment

• The roles of ACOT11 in other cancer types beyond lung carcinoma

• The relationship between ACOT11's metabolic functions and its oncogenic properties

Addressing these questions would advance our understanding of ACOT11 biology and its potential as a therapeutic target.

What experimental approaches might yield new insights into ACOT11 function?

Advanced experimental approaches that could further elucidate ACOT11 function include:

• CRISPR-Cas9 gene editing to create precise ACOT11 functional domain mutations

• Metabolomic profiling to identify specific lipid metabolites regulated by ACOT11

• Single-cell RNA sequencing to characterize ACOT11-expressing cell populations in heterogeneous tumors

• In vivo models with tissue-specific ACOT11 knockout/overexpression

• Structural biology approaches to identify small molecule inhibitors of ACOT11

• Systems biology integration of transcriptomic, proteomic, and metabolomic data to build comprehensive ACOT11 regulatory networks

These approaches would provide multi-dimensional insights into ACOT11 biology and potential therapeutic interventions.

What are the potential translational applications of ACOT11 research?

Based on current knowledge, several translational applications of ACOT11 research merit exploration:

• Development of ACOT11 as a prognostic biomarker for lung cancer patients

• Targeting of ACOT11 enzymatic activity or protein-protein interactions for cancer therapy

• Combination therapies targeting ACOT11 alongside established cancer treatments

• Stratification of patients based on ACOT11 expression for personalized treatment approaches

• Exploration of ACOT11's role in cancer metabolism as a potential vulnerability

These translational directions could eventually lead to improved diagnostic and therapeutic options for cancer patients.