ZNF611 Antibody

What is ZNF611 and what are its known biological functions?

ZNF611 (Zinc Finger Protein 611) is a C2H2-type zinc finger protein that appears to be primarily involved in transcriptional regulation. According to current research findings, ZNF611:

• Functions as a DNA-binding transcription factor

• Binds specifically to SVA (SINE-VNTR-Alu) elements in the human genome

• Shows binding to all SVA subclasses (SVA-A through SVA-F), with particularly strong binding to the VNTR (Variable Number Tandem Repeat) domain

• Is expressed in multiple human tissues and cell lines, including HEK293 cells

Unlike its related protein ZNF91, ZNF611 does not appear to be essential for SVA repression in human embryonic stem cells, despite binding to these elements . The protein exists in multiple isoforms, with isoform a consisting of 705 amino acids and isoform b consisting of 636 amino acids .

What types of ZNF611 antibodies are commercially available for research applications?

Several types of ZNF611 antibodies are available for research, varying in their production methods, host species, and target epitopes:

Most commercially available antibodies show reactivity with human ZNF611, with some also demonstrating cross-reactivity with mouse samples . The N-terminal region (amino acids 1-30) is a common target for several polyclonal antibodies .

What are the recommended applications for ZNF611 antibodies?

ZNF611 antibodies have been validated for multiple laboratory applications with distinct optimization parameters:

• Western Blotting (WB): Most commonly validated application, typically at dilutions of 1:500-1:2000 . Observed molecular weight is approximately 81 kDa .

• ELISA: Validated for most antibodies at dilutions typically around 1:1000 .

• Flow Cytometry (FACS): Several antibodies are validated for flow cytometry at dilutions of 1:10-1:50 .

• Immunofluorescence (IF): Some antibodies, particularly monoclonal variants, have been validated for immunocytochemistry and immunofluorescence applications .

• Immunoprecipitation: Limited validation, but some antibodies like PCRP-ZNF548-1E11 have been recommended for this application .

When designing experiments, researchers should consider that different epitope targets may be more suitable for specific applications - for instance, N-terminal antibodies often perform well in Western blot applications, while full-length antibodies may be preferred for immunofluorescence studies.

How does ZNF611 interact with transposable elements in the human genome?

ZNF611 demonstrates specific binding patterns to SVA (SINE-VNTR-Alu) elements, which are hominid-specific composite retrotransposons. Research indicates:

• ZNF611 binds to approximately 58% of all SVA elements in the human genome

• Binding is primarily localized to the VNTR (Variable Number Tandem Repeat) domain of SVAs

• ZNF611 binding is concentrated in a central part of the VNTR region, compared to ZNF91 which binds at both the Alu-VNTR border and VNTR-SINE domain

• Motif analysis has revealed overlapping binding sites for ZNF611 and ZNF91 within the VNTR region

Interestingly, although ZNF611 binds to SVA elements, genetic deletion experiments in human embryonic stem cells show that unlike ZNF91, ZNF611 is not essential for SVA repression. Deletion of ZNF611 did not lead to transcriptional activation of SVAs, and there was no functional redundancy observed between ZNF91 and ZNF611 .

This suggests that while both proteins bind to similar genomic elements, they likely have distinct functions in controlling transposable element activity and gene regulation.

What methodological approaches can distinguish between ZNF611 and ZNF91 functions in experimental systems?

To differentiate between ZNF611 and ZNF91 functions, researchers have employed several complementary approaches:

• ChIP-seq/ChIP-exo comparison: Studies have used chromatin immunoprecipitation followed by sequencing to compare the binding profiles of both proteins across the genome. This revealed that ZNF91 binds to 88% of SVAs while ZNF611 binds 58%, with differential binding patterns within the SVA structure .

• Motif analysis: Researchers generated binding motifs from top-scoring ChIP peaks to identify the core binding sites of both proteins. This revealed partially overlapping but distinct DNA recognition sequences .

• CRISPR-Cas9 genetic knockouts: The definitive approach has been to create single and double knockout cell lines for ZNF91 and ZNF611 in human embryonic stem cells. By targeting the transcription start sites of these genes, researchers were able to completely abolish their expression and analyze the specific consequences .

• RNA-seq analysis: By comparing transcriptional profiles in wild-type, ZNF91 knockout, ZNF611 knockout, and double knockout cells, researchers determined that only ZNF91 deletion results in SVA activation. A principal component analysis of SVA transcripts clearly separated ZNF91 knockout cells from other genotypes .

• Epigenetic mark analysis: ChIP-seq for repressive (H3K9me3, KAP1) and active (H3K4me3, H3K27ac) histone modifications in the various knockout lines helped establish the specific role of ZNF91, but not ZNF611, in establishing repressive chromatin at SVA elements .

When designing similar experiments, researchers should consider including both single knockouts and double knockouts to assess potential functional redundancy.

What is known about ZNF611 protein structure and its evolutionary conservation?

The ZNF611 protein contains multiple zinc finger domains characteristic of C2H2 zinc finger proteins:

• Human ZNF611 isoform a consists of 705 amino acids, while isoform b has 636 amino acids

• The protein contains multiple zinc finger domains with conserved cysteine and histidine residues that coordinate zinc ions

• The N-terminal region (amino acids 1-30) is a common target for antibody production, suggesting it has distinctive epitopes

Evolutionary analysis has revealed:

• ZNF611 shows only small structural changes across different primate species

• Multiple sequence alignment of ZNF611 from different primates indicates conservation of functional zinc finger domains

• The protein appears to share significant sequence homology with other zinc finger proteins, particularly ZNF600 (87.4% similarity) and ZNF808 (77.6% similarity)

• The predicted DNA binding motif shows some differences between human and ancestral versions that may be relevant for binding SVA elements

When analyzing the evolutionary significance of ZNF611, it's important to note that while it shares binding targets with ZNF91, their functional roles appear to have diverged, with ZNF91 evolving more specialized functions in SVA element repression.

What are the optimal conditions for Western blot analysis using ZNF611 antibodies?

For optimal Western blot results with ZNF611 antibodies, researchers should consider the following protocol elements:

Sample preparation:

• Cell lysates from HEK293 cells, Jurkat cells, or mouse brain tissue have been successfully used for ZNF611 detection

• Standard lysis buffers containing protease inhibitors are recommended

Electrophoresis and transfer:

• Use standard SDS-PAGE with 8-10% gels to properly resolve the ~81 kDa ZNF611 protein

• Transfer to PVDF or nitrocellulose membranes using standard protocols

Antibody incubation:

• Primary antibody dilutions:

  • Polyclonal antibodies: 1:500-1:2000

  • For N-terminal specific antibodies: 1:100-1:500

• Recommended blocking: 5% non-fat milk or BSA in TBST

• Incubation time: Overnight at 4°C for primary antibody

Detection:

• Use appropriate secondary antibodies (anti-rabbit or anti-mouse HRP conjugates)

• Expected band size: ~81 kDa for the main isoform

• Consider longer exposure times if signal is weak

Troubleshooting tips:

• If non-specific bands appear, increase the blocking time or antibody dilution

• For weak signals, reduce antibody dilution or increase protein loading

• For validation, consider using ZNF611 knockout or knockdown samples as negative controls

How can researchers optimize immunofluorescence experiments with ZNF611 antibodies?

For successful immunofluorescence detection of ZNF611, consider the following optimization steps:

Cell fixation and permeabilization:

• 4% paraformaldehyde fixation for 15-20 minutes at room temperature

• Permeabilization with 0.1-0.3% Triton X-100 in PBS for 10 minutes

Blocking and antibody incubation:

• Block with 5-10% normal serum (matching secondary antibody host) in PBS

• Primary antibody dilutions:

  • Monoclonal antibodies (e.g., 4F1 clone): 1:100 for IF applications

  • N-terminal antibodies may require optimization between 1:50-1:200

Visualization and imaging:

• Secondary antibodies: Anti-rabbit or anti-mouse conjugated to fluorophores (Alexa Fluor 488 recommended based on similar protocols)

• Include nuclear counterstain (DAPI)

• Confocal microscopy is preferred for subcellular localization

Expected localization pattern:

• ZNF611, being a transcription factor, should show predominant nuclear localization

• Some punctate nuclear staining may be observed, consistent with binding to specific genomic regions

Controls to include:

• Primary antibody omission control

• Isotype control

• If possible, ZNF611 knockdown or knockout samples

• Consider co-staining with other nuclear markers to confirm localization

While optimizing, remember that protein expression levels may vary across cell types, with documented expression in HEK293 cells, Jurkat cells, and various human tissues .

What considerations are important when designing ChIP experiments targeting ZNF611?

Chromatin immunoprecipitation (ChIP) experiments for ZNF611 require careful planning:

Antibody selection:

• Choose antibodies validated for ChIP applications

• Consider monoclonal antibodies for higher specificity

• Ensure antibody recognizes the native, non-denatured protein form

Cross-linking and chromatin preparation:

• Standard 1% formaldehyde cross-linking for 10 minutes is typically sufficient

• Sonication parameters should be optimized to generate ~200-500bp fragments

• Verify fragmentation by agarose gel electrophoresis

Immunoprecipitation protocol:

• Pre-clear chromatin with protein A/G beads

• Use 2-5 μg of ZNF611 antibody per IP reaction

• Include IgG control and input samples

• Include a positive control antibody (e.g., H3K4me3)

Target validation and analysis:

• qPCR primers should target known ZNF611 binding sites, particularly within SVA elements

• Focus on the VNTR regions of SVA elements, where ZNF611 binding is concentrated

• For ChIP-seq analysis, consider using MACS2 for peak calling

• Compare ZNF611 binding profiles with those of ZNF91 for comprehensive analysis

Data interpretation considerations:

• ZNF611 binds to approximately 58% of SVA elements

• Binding is primarily localized to the central part of the VNTR domain

• ZNF611-bound elements are also frequently bound by ZNF91

• Consider performing motif analysis to identify the core binding sequence

Based on published research, expect significant binding at SVA elements of all subclasses, with particularly strong signals at the VNTR regions.

What experimental controls should be included when studying ZNF611 function?

When investigating ZNF611 function, robust controls are essential for meaningful interpretation:

For protein expression/localization studies:

For functional studies:

• Gene expression analysis:

  • Compare multiple ZNF611 target genes to non-target genes

  • Include analysis of related zinc finger proteins (especially ZNF91)

  • Use RNA-seq to capture genome-wide effects

• Chromatin studies:

  • Include IgG control in ChIP experiments

  • Compare ZNF611 binding with ZNF91 binding patterns

  • Analyze both active (H3K4me3, H3K27ac) and repressive (H3K9me3) histone marks

• Genetic manipulation:

  • Use multiple sgRNAs when creating knockout lines

  • Include single knockouts of ZNF611, ZNF91, and double knockouts to assess redundancy

  • Complement knockout studies with rescue experiments

• Evolutionary context:

  • Compare human ZNF611 function with orthologs from other primates

  • Assess binding to SVA elements from different evolutionary periods