YAH1 Antibody

What is YAH1 and what are its primary cellular functions?

YAH1 functions as a small iron-sulfur protein in the mitochondria of Saccharomyces cerevisiae. It serves as a critical component in the electron transfer chain, transferring electrons through ferredoxin reductase to terminal acceptors such as cytochrome P450 enzymes. YAH1 plays several essential roles:

• Critical downstream regulatory target in the Hippo signaling pathway, crucial for organ size control and tumor suppression by restricting proliferation and promoting apoptosis

• Essential for iron-sulfur (Fe-S) cluster biogenesis and assembly in mitochondria

• Key component in cellular response to copper toxicity

• Involved in mitochondrial integrity and function

• Regulates the cortical actomyosin network, affecting tissue tension and 3D tissue shape

The yeast YAH1 is homologous to human FDX1 (Ferredoxin-1), which performs similar functions in human cells but specifically reduces mitochondrial CYP enzymes essential for adrenal steroidogenesis, bile acid formation, and vitamin D synthesis .

How do researchers validate the specificity of YAH1 antibodies?

A methodological approach to validate YAH1 antibodies includes:

• Western Blot Analysis: Confirm a single band at the expected molecular weight (approximately 19 kDa theoretical, but often observed at 14 kDa) . Compare wild-type cells with YAH1 knockout or knockdown cells.

• Immunoprecipitation Controls: Perform IP with the antibody followed by mass spectrometry analysis to confirm pull-down of YAH1/FDX1 protein.

• Immunofluorescence Cross-validation: Validate subcellular localization by co-staining with established mitochondrial markers.

• Heterologous Expression Systems: Test against recombinant YAH1/FDX1 protein expressed in bacteria or mammalian cells.

• Peptide Competition Assay: Pre-incubate the antibody with immunizing peptide before application to confirm specific binding.

What are optimal experimental conditions for using YAH1 antibodies in Western blotting?

For successful Western blotting with YAH1 antibodies, consider these methodological details:

• Sample Preparation:

  • Isolate mitochondrial fractions for enrichment of target protein

  • Include protease inhibitors and reducing agents (DTT or β-mercaptoethanol) to protect iron-sulfur clusters

  • Avoid prolonged storage of samples before electrophoresis

• Electrophoresis Conditions:

  • Use 12-15% polyacrylamide gels for optimal resolution of small proteins

  • Include positive controls such as recombinant YAH1/FDX1

• Transfer and Blocking:

  • PVDF membranes typically work better than nitrocellulose for small proteins

  • Transfer at lower voltage (30V) overnight at 4°C for efficient transfer

  • Block with 5% non-fat milk in TBS-T (BSA may be necessary for phospho-specific antibodies)

• Antibody Incubation:

  • Recommended dilution range: 1:1000-1:6000 for most commercial YAH1 antibodies

  • Incubate primary antibody overnight at 4°C

  • Wash extensively (5-6 times) with TBS-T

• Detection System:

  • Use high-sensitivity ECL substrates for enhanced detection

  • Consider fluorescent secondary antibodies for quantitative analysis

How can researchers optimize immunoprecipitation protocols using YAH1 antibodies?

For effective immunoprecipitation of YAH1/FDX1:

• Cell Lysis Optimization:

  • Use gentle lysis buffers containing 150-300mM NaCl, 1% NP-40 or Triton X-100, 50mM Tris pH 7.4

  • Include protease inhibitors, phosphatase inhibitors, and 1-2mM DTT

  • Perform lysis at 4°C with minimal mechanical disruption

• Pre-clearing Step:

  • Pre-clear lysate with Protein A/G beads to reduce non-specific binding

  • Centrifuge at 14,000g for 10 minutes before antibody addition

• Antibody Incubation:

  • Use 2-5μg antibody per 500μg-1mg protein lysate

  • Incubate with rotation overnight at 4°C

  • Add 30-50μl of pre-equilibrated Protein A/G beads and incubate for 2-4 hours

• Washing Conditions:

  • Use at least 4 washes with decreasing salt concentration

  • Final wash should be with PBS to remove detergents

• Elution and Analysis:

  • Elute by boiling in SDS sample buffer or use a peptide competition approach for native elution

  • Confirm IP efficiency by Western blot and consider mass spectrometry for interaction partners

How can researchers utilize YAH1 antibodies to investigate iron-sulfur cluster biogenesis?

Investigating iron-sulfur cluster biogenesis with YAH1 antibodies requires multifaceted approaches:

• In vivo Fe-S Cluster Formation Assays:

  • Incorporate 55Fe radiolabeling to track cluster assembly in immunoprecipitated YAH1

  • Compare turnover rates of 55Fe-labeled, immunoprecipitated protein under various stressors

  • Design pulse-chase experiments to measure cluster stability and turnover

• Proximity-dependent Labeling:

  • Create YAH1-BioID or YAH1-APEX2 fusions to identify proximal proteins in the Fe-S biogenesis pathway

  • Validate interactions with co-immunoprecipitation using YAH1 antibodies

• Structure-Function Studies:

  • Use YAH1 antibodies to pull down mutant variants with altered Fe-S binding domains

  • Combine with activity assays to correlate structural integrity with functional output

• Stress Response Analysis:

  • Monitor YAH1 protein levels under oxidative stress, iron starvation, or copper excess

  • Correlate with enzymatic activities of Fe-S dependent enzymes

Research has shown that 55Fe turnover assays reveal that FeS integrity of Yah1 is particularly vulnerable to copper among tested proteins, and destabilization of the FeS domain of Yah1 produces copper hypersensitivity .

What approaches can effectively assess YAH1's role in copper toxicity response?

To investigate YAH1's involvement in copper response:

• Copper Sensitivity Assays:

  • Compare growth inhibition between wild-type and YAH1-overexpressing strains under copper stress

  • Analyze YAH1 mutant strains (e.g., the CR5 mutant) which show increased copper sensitivity

  • Measure dose-response relationships across different copper concentrations

• Molecular Interaction Studies:

  • Investigate interactions between YAH1 and copper homeostasis proteins

  • Use YAH1 antibodies for co-immunoprecipitation under normal and high copper conditions

• Transcriptional Regulation Analysis:

  • Examine how copper influences YAH1 expression levels

  • Monitor downstream targets upon YAH1 perturbation during copper stress

• Mitochondrial Function Assessment:

  • Measure electron transport chain activity in YAH1-depleted cells with/without copper

  • Analyze mitochondrial membrane potential and ROS production

Research has demonstrated that YAH1 overexpression rescues Rli1 dysfunction in copper toxicity conditions, and this copper-resistance function is conserved in the human ferredoxin, Fdx2 .

What methodological considerations are important when using YAH1 antibodies in different yeast genetic backgrounds?

Different yeast genetic backgrounds present unique challenges when working with YAH1 antibodies:

• Strain-Specific Expression Levels:

  • The BY-yeast background has known mitochondrial weaknesses affecting YAH1 detection

  • W303 strains may show different expression patterns requiring antibody titration

  • Industrial strains often have altered metabolism affecting YAH1 expression

• Epitope Accessibility Considerations:

  • Genetic background may influence post-translational modifications affecting antibody binding

  • Consider using multiple antibodies targeting different epitopes

  • Validate each new strain background with appropriate controls

• Genetic Interaction Analysis:

  • When studying double mutants, consider synthetic interactions that might alter YAH1 detection

  • Use quantitative Western blotting to accurately compare expression levels

• Cross-species Applications:

  • When transitioning between yeast species (S. cerevisiae vs. C. albicans), validate epitope conservation

  • Consider creating species-specific antibodies for divergent regions

How can researchers combine YAH1 antibody techniques with other methodologies to study mitochondrial function?

For comprehensive mitochondrial function analysis:

• Multimodal Imaging:

  • Combine immunofluorescence using YAH1 antibodies with live-cell imaging of mitochondrial potential

  • Correlate YAH1 localization with mitochondrial dynamics during stress responses

  • Implement super-resolution microscopy to visualize YAH1 distribution within mitochondrial subcompartments

• Metabolic Profiling Integration:

  • Compare metabolomic profiles between wild-type and YAH1-depleted cells

  • Correlate YAH1 protein levels with changes in TCA cycle intermediates

  • Measure oxygen consumption rates in conjunction with YAH1 expression analysis

• Proteomics Approaches:

  • Use quantitative proteomics to identify changes in the mitochondrial proteome upon YAH1 manipulation

  • Implement thermal proteome profiling to assess YAH1 stability under different conditions

  • Analyze post-translational modifications of YAH1 and interacting partners

• Transcriptional Response Analysis:

  • Combine ChIP-seq using YAH1 antibodies with RNA-seq to correlate YAH1 binding with gene expression

  • Identify transcription factors that regulate YAH1 expression during mitochondrial stress

How can researchers effectively study cross-talk between YAH1 and the Hippo signaling pathway?

For investigating YAH1's involvement in the Hippo pathway:

• Co-immunoprecipitation Studies:

  • Use YAH1 antibodies to pull down complexes and identify interactions with Hippo pathway components

  • Perform reciprocal IPs with Hippo pathway proteins to validate interactions

  • Map interaction domains through truncation mutants

• Phosphorylation Dynamics:

  • Analyze YAH1 phosphorylation status in response to Hippo pathway activation/inhibition

  • Utilize phospho-specific antibodies to track activity-dependent modifications

• Subcellular Localization Studies:

  • Track YAH1 trafficking between mitochondria and other cellular compartments during Hippo signaling

  • Implement proximity ligation assays to validate in situ interactions

• Transcriptional Regulation Analysis:

  • Examine how YAH1 affects TEAD-dependent transcription through reporter assays

  • Analyze YAP1/TAZ nuclear translocation in cells with altered YAH1 levels

YAH1 has been identified as a critical downstream regulatory target in the Hippo signaling pathway, crucial for organ size control and tumor suppression by restricting proliferation and promoting apoptosis .

How should researchers address non-specific binding issues with YAH1 antibodies?

When encountering non-specific binding:

• Antibody Validation Strategies:

  • Test multiple antibody clones targeting different epitopes

  • Validate with knockout/knockdown controls and overexpression systems

  • Consider using tagged versions of YAH1 with antibodies against the tag

• Protocol Optimization:

  • Increase blocking stringency (5% BSA or commercial blocking agents)

  • Apply higher dilution of primary antibody (1:5000-1:6000)

  • Increase washing duration and number of wash steps

  • Add 0.1-0.5% SDS to wash buffer for high stringency

• Sample Preparation Considerations:

  • Enrich for mitochondrial fractions to increase signal-to-noise ratio

  • Reduce sample loading to minimize background

  • Consider native vs. denaturing conditions based on epitope accessibility

• Detection System Adjustment:

  • Use highly specific secondary antibodies with minimal cross-reactivity

  • Consider fluorescent secondaries for quantitative analysis and multiplex detection

What are the methodological considerations for studying YAH1-dependent iron homeostasis?

For iron homeostasis studies:

• Iron Supplementation/Chelation Experiments:

  • Design dose-response studies with iron chelators (e.g., BPS, DFO)

  • Test recovery with iron supplementation after depletion

  • Monitor YAH1 levels throughout iron perturbation

• Fe-S Cluster Transfer Assays:

  • Measure transfer efficiency from YAH1 to recipient proteins in vitro

  • Compare wild-type YAH1 with mutant variants in transfer capability

  • Correlate with functional outputs of recipient proteins

• Iron-specific Cellular Imaging:

  • Implement iron-specific probes alongside YAH1 immunostaining

  • Correlate iron distribution with YAH1 localization

  • Use electron microscopy with gold-labeled antibodies for ultrastructural analysis

• Genetic Interaction Studies:

  • Create double mutants with iron regulatory genes

  • Assess synthetic phenotypes with iron transporters or regulators

  • Use quantitative growth assays under iron limitation/excess

YAH1 has been found to be particularly vulnerable to copper toxicity, which may have implications for iron-sulfur cluster integrity and subsequent iron homeostasis mechanisms .