DNAJC15 Antibody

What is DNAJC15 and why is it relevant to cancer research?

DNAJC15 (DnaJ Heat Shock Protein Family Member C15) is a mitochondrial TIMM23-related co-chaperonin that regulates oxidative phosphorylation efficiency, oxidative stress response, and lipid metabolism. It has gained significant attention in cancer research because its expression levels correlate with chemosensitivity, particularly in ovarian cancer. Loss of DNAJC15 expression due to promoter methylation has been associated with poor prognosis in breast, ovarian, neuroblastoma, and brain cancers . DNAJC15 functions as a negative regulator of the mitochondrial respiratory chain, preventing mitochondrial hyperpolarization and restricting ATP generation, while also acting as an import component of the TIM23 translocase complex and stimulating HSPA9 ATPase activity .

What types of DNAJC15 antibodies are available for research applications?

Researchers have access to both polyclonal and monoclonal DNAJC15 antibodies for various applications:

Both antibody types are typically supplied in PBS with sodium azide and glycerol, requiring storage at -20°C .

How do I select the optimal DNAJC15 antibody for my specific research application?

When selecting a DNAJC15 antibody, consider your experimental application, species of interest, and detection method. For protein localization studies requiring high specificity, monoclonal antibodies may be preferable. For applications needing greater sensitivity with potentially multiple epitope recognition, polyclonal antibodies might be advantageous. Review validation data specific to your application (WB, IHC) and tissue/cell type of interest. For example, Proteintech's 16063-1-AP antibody has been validated in mouse liver tissue and human brain tissue for Western blot applications, while their IHC validation includes human liver tissue . Always review specific dilution recommendations and titrate in your experimental system to optimize signal-to-noise ratios.

What are the recommended protocols for using DNAJC15 antibodies in Western blot applications?

For optimal Western blot results with DNAJC15 antibodies, follow these methodology guidelines:

• Sample preparation: Extract proteins from tissues (e.g., mouse liver, human brain) or cell lines using standard lysis buffers containing protease inhibitors.

• Protein loading: Load approximately 25μg protein per lane as used in validated protocols .

• Antibody dilution: For polyclonal antibodies like 16063-1-AP, use 1:1000-1:4000 dilution ; for monoclonal antibodies, 1:500-1:2000 is recommended .

• Blocking: Use 3% nonfat dry milk in TBST as validated in protocols .

• Secondary antibody: Apply HRP-conjugated anti-Rabbit IgG at approximately 1:10000 dilution .

• Detection: DNAJC15 has an observed molecular weight of 18-20 kDa, which is slightly higher than its calculated molecular weight of 16 kDa .

Always optimize protocols for your specific experimental system, as protein expression levels may vary across tissue and cell types.

How can I optimize immunohistochemistry protocols for DNAJC15 detection in different tissue types?

Successful immunohistochemical detection of DNAJC15 requires careful optimization based on tissue type:

• Fixation and embedding: Use standard formalin fixation and paraffin embedding procedures.

• Antigen retrieval: For polyclonal antibodies like 16063-1-AP, use TE buffer pH 9.0 for optimal retrieval; alternatively, citrate buffer pH 6.0 may be used .

• Antibody dilution: For polyclonal antibodies, use 1:50-1:500 dilution range ; for monoclonal antibodies, 1:100 dilution has been validated on multiple tissues .

• Tissue-specific considerations: DNAJC15 antibodies have been successfully used on multiple tissue types:

  • Human tissues: liver (including liver cancer), kidney

  • Mouse tissues: kidney, heart, testis

• Visualization: Standard DAB or other chromogenic detection systems are suitable.

Remember that each tissue type may require specific optimization of antigen retrieval conditions and antibody concentrations.

What controls should be implemented when working with DNAJC15 antibodies to ensure experimental validity?

Rigorous control implementation is essential for DNAJC15 antibody experiments:

• Positive controls: Use tissues/cells with confirmed DNAJC15 expression:

  • Western blot: Mouse liver tissue, human brain tissue

  • IHC: Human liver tissue

  • Cell lines: HepG2 cells have been validated for Western blot

• Negative controls:

  • Primary antibody omission to assess secondary antibody specificity

  • Isotype controls using non-specific rabbit IgG at equivalent concentrations

  • For advanced validation, DNAJC15 knockdown samples (e.g., using shRNA as in the ovarian cancer study) can serve as biological negative controls

• Expression verification: When manipulating DNAJC15 expression (overexpression or knockdown), verify changes at both mRNA and protein levels .

• Subcellular localization controls: As DNAJC15 is mitochondrial, co-staining with mitochondrial markers can confirm proper localization of detected signals.

How does DNAJC15 expression influence chemoresistance in ovarian cancer?

DNAJC15 plays a crucial role in modulating chemosensitivity in ovarian cancer through several mechanisms:

• Expression correlation: Lower DNAJC15 expression correlates significantly with cisplatin resistance in ovarian cancer cells. The IC50 for cisplatin is significantly higher in resistant cells with low DNAJC15 expression compared to sensitive counterparts .

• Causal relationship: Experimental manipulation of DNAJC15 levels directly impacts cisplatin sensitivity:

  • DNAJC15 overexpression in resistant A2780cis and SKOV3cis cells reduces cisplatin IC50

  • DNAJC15 knockdown in sensitive OC314 cells increases resistance

• Mechanism: DNAJC15 influences chemosensitivity partly through:

  • Regulation of drug efflux mechanisms

  • Modulation of ferroptosis susceptibility

  • Impact on tumorigenic properties and proliferative capabilities

These findings suggest DNAJC15 as a potential prognostic marker and therapeutic target in ovarian cancer.

What experimental approaches are used to study DNAJC15's impact on tumorigenic properties?

Researchers employ multiple complementary approaches to evaluate DNAJC15's influence on cancer cell behavior:

• 2D culture assays:

  • Clonogenic assays demonstrate that DNAJC15 overexpression decreases colony formation capacity, while knockdown increases it

• 3D culture models:

  • Spheroid formation and growth assays show that DNAJC15 overexpression significantly reduces spheroid volume

  • Conversely, DNAJC15 knockdown increases spheroid volume

  • These 3D models better recapitulate in vivo conditions than traditional 2D cultures

• Genetic manipulation strategies:

  • Overexpression using DDK-myc tagged vectors

  • Knockdown using shRNAs with appropriate scramble controls

  • Verification of manipulation success at both mRNA and protein levels, including confirmation of proper mitochondrial localization

• Drug sensitivity testing:

  • Determination of IC50 values for chemotherapeutic agents like cisplatin

  • Assessment of correlation between DNAJC15 levels and drug response

What is the connection between DNAJC15, ferroptosis, and chemoresistance in cancer?

Recent research has revealed a novel connection between DNAJC15, ferroptosis, and chemoresistance:

• Ferroptosis induction: High DNAJC15 expression is associated with:

  • Increased lipid peroxidation

  • Enhanced vulnerability to ferroptosis, an iron-dependent form of cell death

  • Accumulation of lipid droplets

• Mechanistic relationship:

  • DNAJC15 modulates mitochondrial function, which is critical for ferroptosis as mitochondria are major cellular iron stores

  • During ferroptosis, mitochondria undergo alterations in morphology, dynamics, energy metabolism, and oxidative stress

  • DNAJC15's regulation of oxidative phosphorylation may influence the cellular redox state and ferroptosis susceptibility

• Therapeutic implications:

  • Ferroptatin-1 treatment reduces lipid peroxidation, decreases cells' vulnerability to ferroptosis, and recovers cisplatin-resistant phenotypes

  • This suggests that DNAJC15-induced ferroptosis sensitivity is mechanistically linked to cisplatin sensitivity

  • Targeting ferroptosis pathways might overcome chemoresistance in cancers with low DNAJC15 expression

How can contradictory DNAJC15 expression data across different cancer types be reconciled in research?

When encountering contradictory DNAJC15 expression patterns across cancer types, consider these methodological approaches:

• Standardized expression analysis:

  • Use multiple detection methods (RT-qPCR, Western blot, IHC) with validated antibodies

  • Include appropriate housekeeping genes/proteins as loading controls

  • Report fold changes relative to normal tissue from the same patient when possible

• Epigenetic regulation assessment:

  • Analyze methylation status of DNAJC15 promoter CpG islands and 5' coding sequence

  • Methylation has been reported in multiple cancers including breast, ovarian, neuroblastoma, and brain cancers

  • Correlate methylation patterns with expression levels

• Tissue and cell type considerations:

  • Evaluate expression in specific cell populations within heterogeneous tumors

  • Consider microenvironmental influences on expression

  • Analyze expression in cancer stem cells versus differentiated tumor cells

• Clinical correlation:

  • Stratify expression data by patient outcomes, treatment history, and molecular subtypes

  • Consider the confounding effects of previous treatments on DNAJC15 expression

  • Analyze longitudinal samples to track expression changes during disease progression

What are the optimal experimental designs for investigating DNAJC15's role in mitochondrial function?

Comprehensive investigation of DNAJC15's mitochondrial functions requires multi-faceted experimental designs:

• Mitochondrial localization and interaction studies:

  • Immunofluorescence co-localization with mitochondrial markers

  • Submitochondrial fractionation to determine precise localization

  • Co-immunoprecipitation to identify interaction partners (e.g., TIMM23, HSPA9)

  • Proximity ligation assays for in situ protein-protein interaction visualization

• Functional mitochondrial assays:

  • Oxygen consumption rate (OCR) measurement using Seahorse XF analyzers

  • Mitochondrial membrane potential assessment using JC-1 or TMRM dyes

  • ATP production quantification

  • ROS production measurement

• Import assays:

  • In vitro mitochondrial protein import assays with isolated mitochondria

  • Analysis of TIM23 complex function in the presence/absence of DNAJC15

  • Assessment of HSPA9 ATPase activity modulation

• Dynamic mitochondrial responses:

  • Live-cell imaging of mitochondrial morphology and dynamics

  • Assessment of mitochondrial responses to metabolic stress

  • Analysis of mitochondrial quality control pathways (mitophagy, fission/fusion)

How can researchers investigate the relationship between DNAJC15 and lipid metabolism in the context of ferroptosis?

To explore DNAJC15's role in lipid metabolism and ferroptosis, implement these advanced methodological approaches:

• Lipid profiling and peroxidation assessment:

  • Lipidomic analysis to identify specific lipid changes associated with DNAJC15 expression

  • BODIPY staining for lipid droplet quantification

  • C11-BODIPY or LiperFluo for lipid peroxidation measurement

  • 4-HNE immunostaining for detecting lipid peroxidation byproducts

• Iron metabolism analysis:

  • Labile iron pool measurement using fluorescent probes (e.g., Phen Green SK)

  • Iron regulatory protein (IRP) activity assays

  • Assessment of iron-responsive element (IRE)-containing mRNAs

  • Quantification of ferritin and transferrin receptor levels

• Ferroptosis pathway manipulation:

  • Ferroptosis inducers (e.g., erastin, RSL3) dose-response curves

  • Ferroptosis inhibitors (e.g., Ferrostatin-1, liproxstatin-1) rescue experiments

  • Genetic manipulation of key ferroptosis regulators (GPX4, SLC7A11, ACSL4) in DNAJC15-modified cells

• Mechanistic connection investigations:

  • Analysis of mitochondrial phospholipid composition in relation to DNAJC15 levels

  • Assessment of cardiolipin peroxidation specifically

  • Evaluation of DNAJC15's impact on membrane potential and its relationship to lipid metabolism

  • Investigation of potential direct interactions between DNAJC15 and lipid metabolic enzymes

What are the key considerations when validating DNAJC15 as a prognostic biomarker in cancer research?

Rigorous validation of DNAJC15 as a prognostic biomarker requires these methodological considerations:

• Sample collection and processing standardization:

  • Define precise collection, fixation, and storage protocols

  • Establish quality control metrics for sample inclusion

  • Consider both fresh/frozen and FFPE sample types for complementary analyses

• Multi-level detection approach:

  • DNA: Methylation analysis of DNAJC15 promoter using bisulfite sequencing or methylation-specific PCR

  • RNA: Expression quantification using RT-qPCR or RNA-seq

  • Protein: IHC with validated antibodies and standardized scoring systems

• Clinical correlation and statistical validation:

  • Multivariate analysis controlling for clinical variables (age, stage, grade)

  • Kaplan-Meier survival analysis with appropriate statistical testing

  • Time-dependent ROC analysis for prognostic performance

  • Independent validation cohorts with sufficient statistical power

• Integration with existing biomarkers:

  • Assess added prognostic value beyond established markers

  • Develop and validate combinatorial biomarker panels

  • Correlate DNAJC15 status with treatment response for predictive biomarker potential

How can researchers address inconsistent DNAJC15 western blot results across different tissue types?

When encountering variable DNAJC15 western blot results, implement these troubleshooting strategies:

• Sample preparation optimization:

  • Ensure complete protease inhibition during extraction

  • For mitochondrial proteins like DNAJC15, consider mitochondrial enrichment protocols

  • Test different lysis buffers compatible with membrane-associated proteins

  • For tissues with high lipid content, include additional washing steps

• Protein detection refinement:

  • Optimize primary antibody concentration based on tissue type (1:1000-1:4000 for polyclonal, 1:500-1:2000 for monoclonal)

  • Extend primary antibody incubation time (overnight at 4°C)

  • Test both reducing and non-reducing conditions

  • Implement gradient gels to better resolve the 18-20 kDa DNAJC15 protein

• Signal-to-noise optimization:

  • Adjust blocking conditions (3% milk in TBST is validated)

  • Test alternative membrane types (PVDF vs. nitrocellulose)

  • Implement more stringent washing protocols

  • Consider enhanced chemiluminescence systems for low-abundance detection

• Differential expression considerations:

  • Recognize that DNAJC15 levels vary naturally across tissues

  • Load appropriate positive controls (human brain or mouse liver tissue)

  • Consider longer exposure times for tissues with lower expression

What strategies can improve DNAJC15 detection in immunohistochemistry of challenging tissues?

For difficult tissue samples in DNAJC15 IHC applications, implement these advanced techniques:

• Antigen retrieval optimization:

  • Compare TE buffer (pH 9.0) versus citrate buffer (pH 6.0)

  • Test different retrieval times and temperatures

  • For highly fixed tissues, consider protease-based retrieval methods

  • Implement pressure cooker-based retrieval for consistent results

• Signal amplification approaches:

  • Utilize tyramide signal amplification systems for low-abundance detection

  • Consider polymer-based detection systems with higher sensitivity

  • Implement avidin-biotin amplification methods

  • Increase DAB development time while maintaining low background

• Background reduction techniques:

  • Include avidin/biotin blocking for tissues with high endogenous biotin

  • Add FcR blocking for tissues with high FcR expression

  • Pre-absorb primary antibodies with tissue powder from negative control samples

  • Implement dual peroxidase and alkaline phosphatase blocking

• Specialized tissue approaches:

  • For fatty tissues, extend deparaffinization steps

  • For tissues with high pigmentation, consider bleaching protocols

  • For necrotic tumor regions, focus analysis on viable tumor areas

  • For highly autofluorescent tissues, use spectral imaging or chromogenic rather than fluorescent detection