ACC1 Antibody

What is ACC1 and what is its biological significance?

ACC1 (Acetyl-CoA carboxylase 1) is a complex multifunctional enzyme system that catalyzes the carboxylation of acetyl-CoA to malonyl-CoA, which represents the rate-limiting step in fatty acid synthesis. ACC1 is a biotin-containing enzyme highly enriched in lipogenic tissues . There are two main ACC forms: ACC1 (alpha) and ACC2 (beta), encoded by different genes. ACC1 provides materials for fatty acid synthesis (FAS), which requires energy consumption, while ACC2 provides inhibitors of fatty acid oxidation .

The enzyme is regulated at multiple levels:

• Long-term control through transcriptional and translational mechanisms

• Short-term regulation via phosphorylation/dephosphorylation of targeted serine residues

• Allosteric transformation by citrate or palmitoyl-CoA

Beyond its metabolic functions, ACC1 plays critical roles in:

• Regulation of glucagon secretion from pancreatic alpha-cells

• Modulation of cancer cell growth and proliferation

• Inflammatory processes related to T-cell differentiation

What types of ACC1 antibodies are available for research applications?

When selecting an ACC1 antibody, researchers should consider:

• The specific application (WB, IHC, etc.)

• The species reactivity needed (human, mouse, rat, etc.)

• The region of ACC1 to be detected (full-length, specific domains, phosphorylated forms)

• The validation data available for the antibody

How can researchers distinguish between antibodies targeting ACC1 enzyme and the ACC1 antibody that recognizes citrullinated proteins?

This distinction is important as both appear in scientific literature but represent entirely different entities:

ACC1 enzyme antibodies:

• Target the Acetyl-CoA carboxylase 1 enzyme (gene symbol: ACACA)

• Used for studying metabolism, fatty acid synthesis, and related disorders

• Typically recognize epitopes throughout the ~265-275 kDa protein

• Examples include catalog numbers like A15606, A19627, and 67373-1-Ig

ACC1 anti-citrullinated protein antibody:

• A specific monoclonal antibody clone that recognizes citrullinated collagen type II

• Binds to the citrullinated triple-helical C1 epitope (position 359-369)

• Specifically recognizes the second citrulline at position 365 in mouse Collagen Type II

• Relevant to rheumatoid arthritis research

• Found to cause arthritis by cross-reactivity to non-citrullinated epitopes

For clarity in experimental design, always check:

• The molecular weight of the target (ACC1 enzyme is ~265-275 kDa)

• The target protein (ACACA vs. citrullinated collagen)

• The relevant research context (metabolism/cancer vs. autoimmunity)

What are the optimal protocols for detecting ACC1 in Western blot analysis?

Western blot detection of ACC1 requires careful optimization due to its high molecular weight (~265-275 kDa) and complex regulation:

Sample preparation:

• Use RIPA buffer containing both protease and phosphatase inhibitors

• For metabolic tissues (liver, adipose), flash-freeze immediately after collection

• Load 25-50 μg of total protein per lane (more may be needed for tissues with low expression)

Electrophoresis considerations:

• Use low percentage gels (6-8%) for better resolution of high molecular weight proteins

• Run at lower voltage (80-100V) for improved separation

• Consider gradient gels for optimal resolution

Transfer recommendations:

• Wet transfer is preferred for high molecular weight proteins

• Transfer overnight at low voltage (30V) at 4°C

• Use 0.45 μm pore size PVDF membrane rather than 0.2 μm

Antibody incubation:

• Block with 5% BSA in TBST (rather than milk) for phospho-specific detection

• Recommended antibody dilutions range from 1:500 to 1:8000, depending on the specific antibody

• For ACC1 Rabbit pAb (A15606), a dilution of 1:1000 is effective for detecting the 240 kDa band

• For monoclonal antibodies like 67373-1-Ig, higher dilutions (1:10000-1:50000) are recommended

Detection systems:

• Enhanced chemiluminescence (ECL) with longer exposure times may be necessary

• For phosphorylated ACC1, use highly sensitive detection reagents

Controls:

• Positive controls: HepG2, HeLa, or mouse liver lysates show strong ACC1 expression

• Negative control: Sample treated with ACC1-specific siRNA

How should researchers design experiments to study ACC1 phosphorylation status?

ACC1 phosphorylation, particularly at Ser79 by AMPK, is a key regulatory mechanism that inhibits its activity. Properly designed experiments to study this regulation include:

Experimental treatments to modulate ACC1 phosphorylation:

• AMPK activators (metformin, AICAR, exercise, glucose deprivation) increase phosphorylation

• Insulin stimulation decreases phosphorylation

• Fasting/feeding cycles alter phosphorylation status

Sample collection and processing:

• Include phosphatase inhibitors in all buffers

• Rapidly process samples at cold temperatures

• For in vivo studies, flash-freeze tissues immediately after collection

Analytical approaches:

• Western blot analysis:

  • Use phospho-specific antibodies (targeting pSer79)

  • Always normalize to total ACC1 levels

  • Express results as phospho-ACC1/total ACC1 ratio

• Immunoprecipitation:

  • Enrich for ACC1 protein using specific antibodies

  • Probe blots with phospho-specific antibodies

  • Use 0.5-4 μg antibody for 200-400 μg of total protein lysate

• Functional correlation:

  • Link phosphorylation status to enzymatic activity measurements

  • Correlate with metabolic outcomes (lipid synthesis rates, malonyl-CoA levels)

Validation approaches:

• Use phosphatase treatment of some samples as negative controls

• Include genetic models (ACC1 mutants with altered phosphorylation sites)

• Compare results with direct ACC1 activity measurements

What methodological approaches can be used to study ACC1 degradation mechanisms?

The study of ACC1 degradation has revealed important mechanisms in cancer biology, particularly in leukemogenesis. Research has shown that ACC1 can be targeted for ubiquitin-proteasome degradation by complexes such as Trib1-COP1 . Experimental approaches include:

Ubiquitination analysis:

• Immunoprecipitate ACC1, then probe with anti-ubiquitin antibodies

• Treat cells with proteasome inhibitors (MG132) to accumulate ubiquitinated proteins

• Research shows that "ACC1 coexpressed with Tribbles (Trib1, Trib2, and Trib3) and COP1 in cells was strongly polyubiquitinated"

Protein stability assays:

• Cycloheximide chase: Block protein synthesis with cycloheximide, then collect samples at different time points

• Track protein degradation using ACC1 antibodies via Western blot

• Compare stability between wild-type ACC1 and degradation-resistant mutants

Mutational analysis:

• Generate ACC1 mutants lacking potential ubiquitination sites

• Compare stability of wild-type vs. mutant proteins

• The K1759R and Helix1mut mutants show resistance to Trib1-COP1-mediated degradation

Identification of E3 ligase complexes:

• Use ACC1 antibodies for co-immunoprecipitation to identify interaction partners

• Validate interactions with reciprocal co-IPs

• Test effects of ligase activity-deficient mutants (such as Trib1/CSmut)

In vivo degradation studies:

• Generate mouse models expressing degradation-resistant ACC1 mutants

• Use immunohistochemistry with ACC1 antibodies to compare expression patterns

• Analyze phenotypic consequences (metabolism, cancer development)

• Research shows that ACC1 stabilization "delayed the onset of AML with increases in mature myeloid cells in mouse models"

How does ACC1 function in pancreatic alpha cells and what techniques can be used to study its role in glucagon secretion?

Recent research has revealed that ACC1 plays a critical role in alpha cell function and glucagon secretion, with significant implications for diabetes research . Methodological approaches include:

Genetic manipulation strategies:

• Generate alpha cell-specific ACC1 knockout models using Cre-lox technology

• "Transgenic mice expressing Cre-recombinase under the control of the glucagon promoter were crossed with ACC1-floxed mice to generate gluACC1KO"

• Validate deletion using RT-PCR and immunohistochemistry with ACC1 antibodies

Cell isolation techniques:

• Use fluorescence-activated cell sorting (FACS) to isolate alpha cells

• Researchers used "a label-free FACS protocol to enrich primary alpha-cells from dissociated islets"

• Confirm cell identity by glucagon expression and ACC1 deletion

Functional assessment of glucagon secretion:

• Perform static incubation assays with isolated islets

• Measure glucagon secretion in response to glucose challenges

• Research found that "glucagon secretion from gluACC1KO islets was insensitive to changes in glucose concentrations"

Morphological analysis:

• Quantify alpha cell area, number, and size using immunohistochemistry

• Compare pancreatic sections from control and ACC1-knockout mice

• Findings showed that "loss of ACC1 caused a reduction in alpha-cell area of the pancreas, glucagon content and individual alpha-cell size"

Mechanistic investigations:

• Study ATP-sensitive potassium (KATP) channel activity using patch-clamp electrophysiology

• Measure P/Q- and L-type calcium currents

• Analyze S-acylation of the KATP channel subunit using acyl-biotin exchange assays

• Research identified "ACC-dependent alterations in S-acylation of the KATP channel subunit, Kir6.2"

These approaches revealed that ACC1 is essential for normal alpha cell function, with its deletion resulting in impaired glucagon secretion and reduced cell size, suggesting a novel metabolic pathway regulating hormone secretion.

What is the role of ACC1 in cancer metabolism and how can ACC1 antibodies advance cancer research?

ACC1's role in cancer metabolism is complex, with evidence suggesting both tumor-promoting and tumor-suppressing functions depending on the cancer context. ACC1 antibodies enable sophisticated studies through several approaches:

Expression analysis in tumor tissues:

• Use immunohistochemistry with optimized ACC1 antibodies (1:50-1:200 dilution)

• Compare expression across cancer types, stages, and grades

• Human colon carcinoma and breast cancer tissues show strong ACC1 expression

Investigation of ACC1 regulation in cancer:

• Study protein degradation mechanisms using immunoprecipitation with ACC1 antibodies

• Research revealed that "the Trib1-COP1 complex degrades ACC1 through the ubiquitin-proteasome system"

• Expression of degradation-resistant ACC1 mutants suppressed cancer cell growth

Functional consequences of ACC1 modulation:

• Monitor ROS levels and NADPH consumption in cancer cells

• Research found that "stable ACC1 protein expression suppressed the growth-promoting activity and increased ROS levels with the consumption of NADPH"

• Correlate ACC1 expression with metabolic parameters and cell growth

In vivo cancer models:

• Generate models with altered ACC1 expression or stability

• Track cancer progression using appropriate markers

• Studies showed that ACC1 stabilization "delayed the onset of AML with increases in mature myeloid cells in mouse models"

• ACC1 "promoted the terminal differentiation of Trib1-COP1–expressing cells and eradicated leukemia-initiating cells"

Therapeutic implications:

• Test effects of ACC1 modulators on cancer cell growth

• Investigate synergy with conventional cancer therapies

• Research indicates that "ACC1 is a natural inhibitor of AML development" and "upregulated expression of the ACC1 protein has potential as an effective strategy for cancer therapy"

These findings highlight ACC1's complex role in cancer, revealing unexpected tumor-suppressive functions in certain contexts and suggesting new therapeutic opportunities.

How can researchers investigate the role of ACC1 antibodies in autoimmune diseases?

When studying ACC1 in autoimmunity contexts, it's important to distinguish between two separate entities:

• The metabolic enzyme ACC1 and its role in immune cell function

• The specific monoclonal antibody called ACC1 that recognizes citrullinated proteins in rheumatoid arthritis

For the ACC1 antibody that targets citrullinated proteins, research approaches include:

Characterization of binding specificity:

• The ACC1 antibody "recognizes the second citrulline at position 365 in mouse Collagen Type II"

• It "binds to flexible triple-helical Collagen Type II determinants and many citrullinated CII peptides"

• Studies showed it "was found to cross-react with several non-citrullinated epitopes on native Collagen Type II"

Structural analysis of antibody-epitope interactions:

• Use X-ray crystallography to study binding mechanisms

• Research revealed that "recognition is governed by a shared structural motif 'RG-TG' within all the epitopes, including electrostatic potential-controlled citrulline specificity"

In vivo pathogenicity studies:

• Transfer purified antibodies to animal models

• Analyze effects on joint inflammation and cartilage integrity

• Studies found that the ACC1 antibody could cause "proteoglycan depletion of cartilage and severe arthritis in mice"

Contrasting research findings:

• Recent studies provide conflicting evidence on arthritogenicity

• Some research indicates that "none of the ACPAs showed arthritogenicity nor induced pain-associated behavior in mice"

• Certain antibodies may even be protective, with one study showing an antibody that "protected mice from antibody-induced arthritis"

• This protection was "epitope-specific and dependent on the interaction between E4-citrullinated α-enolase immune complexes with FCGR2B on macrophages, resulting in increased IL-10 secretion"

This area of research highlights the complexity of autoantibody functions in rheumatoid arthritis, with some antibodies promoting pathology while others may have protective effects.

What are the common challenges when using ACC1 antibodies in Western blot and how can they be resolved?

Working with ACC1 in Western blot presents several challenges due to its high molecular weight and complex regulation:

ACC1-specific considerations:

• For the high molecular weight of ACC1 (~265-275 kDa):

  • Use low percentage gels (6-8%)

  • Extend transfer time for large proteins

  • Consider wet transfer methods rather than semi-dry

• For phosphorylation detection:

  • Block with BSA rather than milk

  • Include phosphatase inhibitors in all buffers

  • Compare results with total ACC1 antibodies

• Verification strategies:

  • Use positive control lysates (HepG2, HeLa, mouse liver)

  • Include siRNA knockdown samples as negative controls

  • Test multiple ACC1 antibodies targeting different epitopes

How can researchers optimize immunohistochemistry protocols for ACC1 detection in different tissue types?

Successful immunohistochemical detection of ACC1 requires optimization based on tissue type and experimental needs:

Antigen retrieval optimization:

• Primary recommendation: TE buffer pH 9.0

• Alternative: citrate buffer pH 6.0

• Heat-induced epitope retrieval methods (pressure cooker or microwave)

• Optimal retrieval conditions may vary by tissue type and fixation method

Antibody selection and dilution:

• For ACC1 Rabbit pAb (A15606), recommended dilutions are 1:50-1:200

• For monoclonal antibodies, such as 67373-1-Ig, use 1:500-1:2000

• Test multiple dilutions to determine optimal concentration

Tissue-specific considerations:

• Liver: Shows strong endogenous expression, may need higher antibody dilutions

• Adipose tissue: May require additional steps to remove lipids

• Muscle: Additional permeabilization may be beneficial

• Pancreatic islets: Consider co-staining with cell type markers (insulin, glucagon)

Detection systems:

• For tissues with lower expression: Consider signal amplification systems

• For co-localization studies: Use fluorescent secondary antibodies

• For quantitative analysis: DAB detection with standardized development times

Controls:

• Positive tissue controls: Liver, adipose tissue, colon carcinoma

• Negative controls: Primary antibody omission, isotype controls

• Specificity controls: Pre-adsorption with immunizing peptide, ACC1 knockdown tissues

Validation examples:

• Successful IHC has been demonstrated in human colon carcinoma, human liver, and breast cancer tissue

• Antigen retrieval with high pressure in citrate buffer pH 6.0 has shown good results

How can researchers differentiate between ACC1 and ACC2 in experimental systems?

Distinguishing between ACC1 and ACC2 isoforms is crucial for understanding their distinct metabolic functions:

Expression pattern analysis:

• ACC1 (Acaca) mRNA expression is typically higher than ACC2 (Acacb) in many tissues

• Research found "ACC1 (Acaca) mRNA expression was ~18-fold higher than ACC2 (Acacb) in alpha-cells, and ~121-fold higher than ACC2 in beta-cells"

Isoform-specific antibody selection:

• Choose antibodies targeting unique regions of ACC1 vs. ACC2

• Validate specificity using Western blotting in tissues with known differential expression

• Test in knockout/knockdown models when available

Genetic manipulation approaches:

• Generate isoform-specific knockdowns using targeted siRNAs

• Create conditional knockout models for specific tissues

• The search results describe "gluACC1KO mice" with alpha cell-specific deletion of ACC1

Combined approaches for functional differentiation:

• Subcellular localization:

  • ACC1 is primarily cytosolic while ACC2 associates with mitochondria

  • Use confocal microscopy with isoform-specific antibodies

  • Co-stain with organelle markers

• Functional assays:

  • Measure fatty acid synthesis rates (primarily ACC1 function)

  • Assess fatty acid oxidation (influenced by ACC2)

  • Correlate with protein levels detected by isoform-specific antibodies

• Metabolic profiling:

  • Analyze malonyl-CoA levels in different cellular compartments

  • Measure lipid synthesis versus oxidation rates

  • Connect metabolic outcomes to specific isoform activity

These approaches allow researchers to distinguish the specific roles of ACC1 and ACC2 in various physiological and pathological contexts.

How can researchers use ACC1 antibodies to investigate post-translational modifications beyond phosphorylation?

While phosphorylation is the most studied modification of ACC1, recent research has revealed other important post-translational modifications that can be investigated:

Ubiquitination studies:

• Immunoprecipitate ACC1 using specific antibodies, then probe with anti-ubiquitin antibodies

• Research demonstrated that "ACC1 coexpressed with Tribbles (Trib1, Trib2, and Trib3) and COP1 in cells was strongly polyubiquitinated"

• Treatment with proteasome inhibitors like MG132 can help accumulate ubiquitinated forms

S-acylation analysis:

• ACC1 has been linked to S-acylation of proteins in alpha cells

• Research identified "ACC-dependent alterations in S-acylation of the KATP channel subunit, Kir6.2"

• Use acyl-biotin exchange assays to detect protein S-acylation

Acetylation investigations:

• Some research suggests ACC1 may regulate protein acetylation

• Studies indicated that "ACC1 acts as a tumor suppressor by regulating the energy balance and suppressing protein acetylation in solid tumor xenograft models"

• Compare acetylation patterns in systems with normal vs. altered ACC1 levels

Methodological approaches:

• Mass spectrometry:

  • Enrichment of ACC1 by immunoprecipitation

  • Analysis of post-translational modifications using proteomic approaches

  • Quantitative comparison across different conditions

• Site-specific mutants:

  • Generate ACC1 mutants lacking specific modification sites

  • Compare functional consequences

  • Validate using antibodies against specific modifications

• Proximity labeling:

  • Use BioID or APEX2 fusions with ACC1

  • Identify proteins in close proximity that might modify ACC1

  • Validate interactions using co-immunoprecipitation with ACC1 antibodies

These investigations will provide deeper insights into the complex regulation of ACC1 and its roles in health and disease.

What emerging applications of ACC1 antibodies show promise for translational research?

ACC1 research is increasingly revealing opportunities for translational applications in multiple disease areas:

Cancer therapeutics:

• ACC1 stabilization has shown promise in leukemia models

• Research found that "stable ACC1 protein expression suppressed the growth-promoting activity" and "delayed the onset of AML"

• ACC1 antibodies can help identify patients who might benefit from metabolism-targeting therapies

• Use IHC with ACC1 antibodies to stratify tumors based on expression patterns

Metabolic disorders:

• Dysregulated ACC1 contributes to conditions like fatty liver disease and insulin resistance

• Monitor ACC1 expression and phosphorylation status as biomarkers of metabolic health

• Study effects of existing drugs (like metformin) on ACC1 regulation

Diabetes research:

• ACC1's role in glucagon secretion has significant implications for diabetes

• Research demonstrated that ACC1 "plays a critical role in the intrinsic regulation of glucagon secretion"

• ACC1 antibodies can help monitor changes in islet cell biology during disease progression

• Potential development of targeted therapies for dysregulated glucagon secretion

Autoimmune disease biomarkers:

• Anti-citrullinated protein antibodies (including ACC1) are hallmarks of rheumatoid arthritis

• Some research suggests these antibodies have different functional effects

• One study found that a specific antibody "protected mice from antibody-induced arthritis"

• Monitoring specific antibody profiles might help predict disease course or treatment response

Methodological advances:

• Development of antibodies targeting specific ACC1 phosphorylation sites for monitoring pathway activation

• Creation of proximity-labeling tools to study ACC1 interactome in different disease contexts

• Application in advanced imaging techniques to monitor ACC1 dynamics in living systems

These translational applications highlight ACC1's emerging importance as both a therapeutic target and biomarker across multiple disease areas.