FUN14 Antibody

What is FUNDC1 and where is it primarily expressed?

FUNDC1 is an integral mitochondrial outer-membrane protein that mediates several critical cellular functions. It shows particularly high expression levels in tissues with high energy demands such as the heart and skeletal muscles . The protein contains a FUN14 domain and is encoded by the FUNDC1 gene (GeneID: 139341) . With a molecular weight of approximately 17 kDa, FUNDC1 serves as a key mediator in mitochondrial quality control and cellular homeostasis .

What types of FUNDC1 antibodies are available for research?

Several types of FUNDC1 antibodies are available for research applications. These primarily include rabbit polyclonal antibodies, some of which are conjugated with fluorescent markers like FITC (fluorescein isothiocyanate) . The antibodies are typically raised against synthetic peptides from the N-terminal region (amino acids 1-50) or recombinant fragments of human FUNDC1 protein . Both labeled and unlabeled antibodies are available depending on the intended application and detection method required for experiments.

What applications are FUNDC1 antibodies suitable for?

FUNDC1 antibodies are validated for several common laboratory techniques. Western blotting (WB) is the most frequently verified application, with recommended dilutions typically around 1:1000 . Immunohistochemistry on paraffin-embedded sections (IHC-P) is another validated application, often using dilutions around 1:50 . While less commonly mentioned in the search results, some antibodies might also be suitable for immunofluorescence, immunoprecipitation, or flow cytometry applications depending on the specific antibody preparation and validation data provided by manufacturers.

What species reactivity can be expected from FUNDC1 antibodies?

The available FUNDC1 antibodies show reactivity with different species, though this varies by product. Many antibodies react with human FUNDC1 . Some products also demonstrate cross-reactivity with mouse FUNDC1 . Certain antibodies may additionally react with rat FUNDC1 . When selecting an antibody for research, it's essential to verify the specific species reactivity needed for your experimental model, as this can vary significantly between different antibody products.

How does FUNDC1 function in mitochondrial quality control and mitophagy?

FUNDC1 serves as an activator of hypoxia-induced mitophagy, which is a critical mechanism for maintaining mitochondrial quality and cellular homeostasis . Mechanistically, FUNDC1 interacts with and recruits members of the LC3 protein family to mitochondria, facilitating the recognition and subsequent degradation of damaged mitochondria . During hypoxic conditions, FUNDC1 recruits DRP1 (Dynamin-related protein 1) to ER-mitochondria contact sites, promoting DRP1 oligomerization and GTPase activity . This recruitment facilitates mitochondrial fission, an essential step in the mitophagy process that allows for the segregation of damaged mitochondrial segments for subsequent degradation .

What is the relationship between FUNDC1 and endoplasmic reticulum-mitochondria communication?

FUNDC1 plays a crucial role in mediating the formation of mitochondria-associated endoplasmic reticulum membranes (MAMs) . These specialized membrane contact sites between mitochondria and the endoplasmic reticulum are essential for various cellular processes, including calcium signaling, lipid transfer, and mitochondrial dynamics. Through these MAMs, FUNDC1 influences intracellular Ca²⁺ communication between the two organelles . This calcium signaling is critical for numerous cellular functions, including energy production, apoptosis regulation, and cellular stress responses.

How does FUNDC1 contribute to angiogenesis and vascular development?

FUNDC1 mediates angiogenesis and neoangiogenesis through two primary mechanisms . First, it interferes with intracellular Ca²⁺ communication between the endoplasmic reticulum and mitochondria, which affects numerous downstream signaling pathways involved in endothelial cell function. Second, FUNDC1 regulates the expression of the vascular endothelial growth factor receptor KDR/VEGFR2 at both mRNA and protein levels . This regulation of VEGFR2, a key receptor in angiogenic signaling, allows FUNDC1 to influence vascular development, endothelial cell proliferation, migration, and blood vessel formation.

What role does FUNDC1 play in ferroptosis?

FUNDC1 has been identified as a contributor to hepatic ferroptosis, a form of regulated cell death characterized by iron-dependent lipid peroxidation . Mechanistically, FUNDC1 interacts directly with glutathione peroxidase 4 (GPX4), a critical enzyme that protects cells against ferroptosis by reducing lipid hydroperoxides . FUNDC1 facilitates the recruitment of GPX4 into mitochondria through the TOM/TIM complex (translocase of the outer/inner membrane), where GPX4 is subsequently degraded through mitophagy . This degradation of GPX4 increases cellular susceptibility to ferroptotic cell death, particularly in hepatic tissues.

How is FUNDC1 implicated in cancer biology?

Research indicates that FUNDC1 promotes breast cancer proliferation . While detailed mechanisms require further investigation, the connection likely involves FUNDC1's roles in mitochondrial dynamics, calcium signaling, and cell death regulation. In breast cancer tissues, immunohistochemical analysis of FUNDC1 expression can be performed using specific antibodies (such as Abcam ab173226) at a 1:500 dilution . FUNDC1 appears to have connections with BMI1, potentially involving signaling through NFATC1 motifs as suggested by luciferase reporter assays and chromatin immunoprecipitation experiments in breast cancer models .

What are the optimal conditions for immunohistochemistry with FUNDC1 antibodies?

For immunohistochemistry on paraffin-embedded tissues (IHC-P), FUNDC1 antibodies typically work well at dilutions ranging from 1:50 to 1:500, depending on the specific antibody and tissue preparation . The tissue preparation process should include deparaffinization, antigen retrieval using citrate buffer (pH 6.0), blocking of endogenous peroxidase activity with hydrogen peroxide, and serum blocking with bovine serum albumin (BSA) . Following primary antibody incubation, appropriate secondary antibodies should be applied, and visualization can be achieved using DAB (3,3'-Diaminobenzidine) solution. Hematoxylin counterstaining can be employed to visualize nuclei .

What controls should be included when working with FUNDC1 antibodies?

When working with FUNDC1 antibodies, several controls should be included to ensure experimental validity. Negative controls typically employ isotype-matched immunoglobulins (such as rabbit IgG) instead of the primary antibody . Positive controls should include tissues known to express high levels of FUNDC1, such as heart or skeletal muscle samples . For quantitative analyses, a scoring system that accounts for both staining intensity and the percentage of positive cells can be employed, with final scores ranging from 0 to 12 based on multiplying intensity scores (0-3) with extent scores (0-4) .

What are the recommended storage conditions for FUNDC1 antibodies?

FUNDC1 antibodies should typically be stored at -20°C in small aliquots to prevent repeated freeze-thaw cycles that can degrade antibody quality . For FITC-conjugated antibodies, special precautions should be taken to avoid exposure to light, as fluorophores are light-sensitive and can photobleach . Most FUNDC1 antibodies are supplied in buffers containing stabilizers like glycerol (often at 50%) and preservatives such as sodium azide (0.09%) or Proclin-300 (0.03%) . These storage conditions help maintain antibody stability and functionality for extended periods.

What dilutions are recommended for Western blotting with FUNDC1 antibodies?

For Western blotting applications, FUNDC1 antibodies are typically recommended at dilutions ranging from 1:500 to 1:1000 . The exact optimal dilution may vary depending on the specific antibody preparation, the expression level of FUNDC1 in the sample, and the detection method employed. When using FUNDC1 antibodies for Western blotting, they should detect a band at approximately 17 kDa, which corresponds to the molecular weight of the FUNDC1 protein . As with all antibody applications, optimization of dilution ratios for specific experimental conditions may be necessary.

Why might Western blots with FUNDC1 antibodies show multiple bands?

Multiple bands in Western blots using FUNDC1 antibodies could occur for several reasons. FUNDC1 may undergo post-translational modifications like phosphorylation, particularly under conditions such as hypoxia that activate its mitophagy function . Additionally, since FUNDC1 is involved in protein-protein interactions with multiple partners including LC3, DRP1, and GPX4, some cross-reactivity might occur in certain sample preparations . Ensuring proper sample preparation, including effective denaturation, appropriate blocking, and stringent washing conditions, can help minimize non-specific binding. Verification with knockout or knockdown controls would be valuable to confirm band specificity.

How can background be reduced in immunohistochemistry with FUNDC1 antibodies?

To reduce background staining in immunohistochemistry using FUNDC1 antibodies, several approaches can be implemented. Thorough blocking with 3% bovine serum albumin (BSA) or appropriate blocking reagents is essential . Optimization of primary antibody dilution is critical, as too concentrated antibody solutions can increase non-specific binding. Using appropriate antigen retrieval methods, such as citrate buffer treatment, can improve specific staining while reducing background . Additionally, including adequate washing steps between incubations and careful titration of the detection system components can significantly improve signal-to-noise ratios in FUNDC1 immunohistochemistry.

What are special considerations when working with FITC-conjugated FUNDC1 antibodies?

When working with FITC-conjugated FUNDC1 antibodies, several special considerations apply. These antibodies have specific excitation/emission profiles (499/515 nm) and are typically used with the 488 nm laser line . To maintain fluorophore integrity, they must be protected from light exposure during storage and handling to prevent photobleaching . For microscopy applications, appropriate filters must be used to capture the specific emission wavelength. Additionally, tissue autofluorescence in the green spectrum can sometimes interfere with FITC signals, so proper controls and potentially spectral unmixing might be necessary for accurate data interpretation.

How can cross-reactivity issues be addressed when using FUNDC1 antibodies?

To address potential cross-reactivity issues with FUNDC1 antibodies, researchers should implement several strategies. First, antibodies raised against synthetic peptides or recombinant fragments unique to FUNDC1 should be selected . Pre-absorption controls, where the antibody is pre-incubated with excess antigen before application to samples, can help confirm specificity. Validation in samples with FUNDC1 knockdown or knockout is the gold standard for confirming antibody specificity. Additionally, comparing staining patterns across multiple FUNDC1 antibodies targeting different epitopes can increase confidence in the observed results and help distinguish true signal from cross-reactivity artifacts.