ACSS3 Antibody

What is ACSS3 and what is its primary function in cellular metabolism?

ACSS3 belongs to the ATP-dependent AMP-binding enzyme family and is primarily localized to the mitochondrial inner membrane. Its primary function is to activate acetate for lipid synthesis or energy generation . More specifically, ACSS3 catalyzes the synthesis of acetyl-CoA from short-chain fatty acids and plays a critical role in propionate catabolism, particularly in brown adipose tissue . The protein contains 686 amino acids with a molecular weight of approximately 75 kDa, and features 4 of 5 motifs that are characteristic of acyl-CoA synthetases .

In which tissues and cell types is ACSS3 predominantly expressed?

ACSS3 shows notable expression in several tissues and organs. According to proteomic analyses, it is highly expressed in the parathyroid gland, kidney, gallbladder, epididymis, and adrenal gland . Of particular interest to metabolic researchers, ACSS3 is abundantly expressed in brown adipose tissue (BAT), where it plays a significant role in propionate metabolism . The subcellular localization of ACSS3 is primarily in the mitochondria, specifically on the inner mitochondrial membrane .

What are the recommended protocols for using ACSS3 antibodies in Western Blot applications?

For Western Blot applications, the following recommendations apply based on validated protocols:

• Sample preparation: ACSS3 has been successfully detected in various samples including HepG2 cells, mouse kidney tissue, and rat kidney tissue .

• Antibody dilution: The recommended dilution range for polyclonal anti-ACSS3 antibodies in Western Blot is 1:1000-1:5000 . It's advisable to perform a dilution series to determine optimal conditions for your specific experimental system.

• Expected molecular weight: The observed molecular weight for ACSS3 in Western Blot is typically between 70-75 kDa , which corresponds well with the calculated molecular weight of 75 kDa for the 686 amino acid protein.

• Loading controls: Common loading controls used in published ACSS3 Western Blot experiments include β-Tubulin (dilution 1:5000) and GAPDH (dilution 1:1000) .

How should ACSS3 antibodies be used for immunohistochemistry and immunofluorescence applications?

For immunohistochemistry (IHC) and immunofluorescence (IF) applications:

• IHC protocol recommendations:

  • Dilution range: 1:20-1:200 for polyclonal antibodies

  • Antigen retrieval: Use TE buffer pH 9.0 (alternatively, citrate buffer pH 6.0 may be used)

  • Positive control tissues: Human liver tissue has been validated for ACSS3 detection by IHC

• IF/ICC protocol recommendations:

  • Dilution range: 1:200-1:800

  • Validated cell lines: U2OS cells have shown positive staining for ACSS3 in IF/ICC applications

• Storage and handling: Most ACSS3 antibodies should be stored at -20°C and are stable for one year after shipment. For long-term storage, antibodies in PBS with 0.02% sodium azide and 50% glycerol (pH 7.3) are recommended .

What is the role of ACSS3 in cancer research and how are ACSS3 antibodies utilized in this field?

ACSS3 has emerged as a significant factor in cancer research, with potential applications as both a biomarker and therapeutic target:

Researchers utilize ACSS3 antibodies in this context primarily for:

• Evaluating ACSS3 expression levels in tumor tissues via IHC

• Quantifying ACSS3 protein levels in cancer cell lines through Western Blot

• Investigating ACSS3's subcellular localization in cancer cells using IF/ICC

How is ACSS3 involved in metabolic disorders and what insights have antibody-based studies provided?

ACSS3 plays a crucial role in metabolic processes, particularly in adipose tissue metabolism:

• Role in brown adipose tissue: ACSS3 is highly expressed in brown adipose tissue (BAT) and is essential for propionate metabolism. Located on the mitochondrial inner membrane, it activates propionate in the propionate catabolism pathway .

• Impact on obesity and insulin resistance: Knockout studies have shown that deletion of the Acss3 gene in mice reduces BAT mass but increases white adipose tissue (WAT) mass, leading to glucose intolerance and insulin resistance. These effects are exacerbated by high-fat diet (HFD) feeding .

• Propionate metabolism: Acss3 knockout or HFD feeding significantly elevates propionate levels in BAT and serum. This elevated propionate induces autophagy in cultured brown and white adipocytes, driving adipocyte autophagy that contributes to obesity and metabolic syndrome .

• Therapeutic implications: Pharmacological inhibition of autophagy using hydroxychloroquine ameliorates obesity, hepatic steatosis, and insulin resistance in Acss3 knockout mice, suggesting potential therapeutic approaches for metabolic disorders .

ACSS3 antibodies have been instrumental in elucidating these mechanisms through:

• Detection of ACSS3 expression in different adipose tissue types

• Confirmation of ACSS3 localization to the mitochondrial inner membrane

• Validation of ACSS3 knockout models

• Analysis of downstream metabolic effects in various tissues

How can researchers address cross-reactivity concerns when using ACSS3 antibodies?

Cross-reactivity is an important consideration when working with antibodies targeting members of protein families. For ACSS3 antibodies:

• ACSS family homology: ACSS3 belongs to the acyl-CoA synthetase short-chain family, which includes other members like ACSS1 and ACSS2. These proteins share structural similarities that could potentially lead to cross-reactivity .

• Validation strategies:

  • Western Blot with positive and negative controls: Include samples with known ACSS3 expression levels as well as samples from knockout models or ACSS3-depleted cells to confirm specificity.

  • Peptide competition assays: Pre-incubating the antibody with excess ACSS3 peptide should abolish specific signals.

  • Alternative antibodies: Use antibodies raised against different epitopes of ACSS3 to confirm findings.

  • Cross-validation with other techniques: Combine antibody-based detection with mRNA expression analysis or mass spectrometry.

• Species considerations: While many ACSS3 antibodies show cross-reactivity between human, mouse, and rat samples , it's important to verify specificity for your species of interest, particularly for less commonly studied organisms.

What are the critical factors affecting reproducibility in ACSS3 antibody-based experiments?

Several factors can influence the reproducibility of experiments using ACSS3 antibodies:

• Antibody quality and validation:

  • Lot-to-lot variation: Different lots of the same antibody may show variation in specificity and sensitivity.

  • Validation status: Check if the antibody has been validated for your specific application and cell/tissue type.

  • Storage conditions: Improper storage can lead to antibody degradation. Most ACSS3 antibodies should be stored at -20°C or -80°C .

• Experimental conditions:

  • Sample preparation: Variations in cell lysis methods, buffer compositions, or tissue processing can affect ACSS3 detection.

  • Protocol optimization: Antibody dilution, incubation time, and washing steps should be optimized for each experimental system.

  • Antigen retrieval methods: For IHC applications, the choice between TE buffer pH 9.0 and citrate buffer pH 6.0 can impact results .

• Biological variables:

  • Cell/tissue state: ACSS3 expression may vary depending on metabolic conditions, cell confluence, or tissue microenvironment.

  • Nutritional status: Given ACSS3's role in metabolism, the nutritional state of cells or animals can significantly impact its expression level .

How are ACSS3 antibodies being used to investigate its role in the immune microenvironment of cancer?

Recent research has begun exploring the relationship between ACSS3 and the immune microenvironment in various cancers:

• Immune cell infiltration: ACSS3 expression has been found to correlate with immune cell infiltration patterns in different tumor types. Researchers are using antibodies to assess ACSS3 expression in tumor tissues and correlating these findings with immune cell profiles .

• Immune checkpoint interactions: Studies have investigated the relationship between ACSS3 expression levels and immune checkpoint inhibitors (ICIs) response. Tools like the Cancer Immunomics Atlas (TCIA), TIDE (Tumor Immune Dysfunction and Exclusion), and ImmuCellAI (Immune Cell Abundance Identifier) have been used to assess this relationship .

• Single-cell resolution analysis: Advanced techniques combining ACSS3 antibody staining with single-cell sequencing data (from databases like TISCH) are being employed to validate tumor microenvironment results with single-cell resolution, providing deeper insights into the cellular context of ACSS3 expression .

• Immune cycle impact: ACSS3 expression has been assessed in relation to the seven stages of the cancer immune cycle, including cancer cell antigen release, antigen presentation, immune cell activation, transportation, infiltration, recognition, and killing of cancer cells .

What novel therapeutic approaches are being investigated based on ACSS3 function, and how do antibodies contribute to this research?

Emerging research on ACSS3 has revealed potential therapeutic approaches in several disease contexts:

• Cancer therapy: Given ACSS3's role in promoting cancer cell growth under metabolic stress conditions, it represents a promising target for cancer treatment, particularly for bladder cancer . Researchers are using antibodies to:

  • Evaluate ACSS3 expression levels in patient samples to identify candidates for targeted therapy

  • Monitor changes in ACSS3 expression in response to existing treatments

  • Develop and test ACSS3-targeted therapeutic approaches

• Metabolic disorders: The discovery that ACSS3 deficiency leads to propionate accumulation, which triggers adipocyte autophagy and promotes obesity, has opened new therapeutic avenues . Researchers are exploring:

  • Autophagy inhibitors like hydroxychloroquine to counteract the metabolic effects of propionate accumulation

  • Strategies to modulate ACSS3 activity to maintain proper propionate metabolism

  • ACSS3 antibodies are essential for monitoring treatment effects at the protein level

• Drug discovery: The GSCA database and CellMiner tools are being used to identify small molecule compounds that may affect ACSS3 expression or function . Antibodies play a crucial role in:

  • High-throughput screening assays to identify compounds affecting ACSS3

  • Validation of hit compounds in cellular models

  • Mechanistic studies to understand how these compounds modulate ACSS3 activity

What are common challenges when detecting ACSS3 in tissue samples, and how can they be addressed?

Researchers may encounter several challenges when detecting ACSS3 in tissue samples:

• Low signal intensity:

  • Solution: Optimize antigen retrieval methods. For ACSS3, TE buffer pH 9.0 is recommended, though citrate buffer pH 6.0 may also work .

  • Alternative approach: Try signal amplification systems or more sensitive detection methods.

• Background staining:

  • Solution: Increase blocking time or concentration, optimize antibody dilution (1:20-1:200 for IHC), and ensure thorough washing between steps .

  • Alternative approach: Use more specific secondary antibodies or alternative detection systems.

• Tissue-specific variations:

  • Solution: ACSS3 is highly expressed in specific tissues like parathyroid gland, kidney, gallbladder, epididymis, and adrenal gland . Use these as positive controls when optimizing protocols.

  • Alternative approach: Adjust fixation protocols based on the specific tissue being examined.

• Degradation during processing:

  • Solution: Minimize time between tissue collection and fixation, and ensure proper fixation conditions.

  • Alternative approach: Consider using frozen sections rather than paraffin-embedded tissues for certain applications.

How can researchers differentiate between ACSS3 isoforms using antibody-based techniques?

ACSS3 can exist in different isoforms, with up to 2 isoforms reported due to alternative splicing . To differentiate between these isoforms:

• Isoform-specific antibodies:

  • Selection strategy: Choose antibodies raised against epitopes unique to specific isoforms.

  • Validation: Confirm isoform specificity using overexpression systems or isoform-specific knockdown.

• Western Blot analysis:

  • Resolution: Use lower percentage gels (6-8%) to better separate high molecular weight isoforms.

  • Expected patterns: The full-length ACSS3 protein has a transit peptide with 29 amino acids , which affects the observed molecular weight.

  • Controls: Include recombinant ACSS3 isoforms as size references.

• Combined approaches:

  • RT-PCR + Western Blot: Complement protein detection with mRNA analysis to identify which isoforms are being expressed.

  • Mass spectrometry: Use antibodies for immunoprecipitation followed by mass spectrometry to identify specific isoforms.

• Subcellular localization:

  • Immunofluorescence: Different isoforms may show distinct subcellular localization patterns, with the full-length form primarily in mitochondria .

  • Fractionation: Combine cell fractionation with Western Blot to analyze isoform distribution across cellular compartments.