HaploChIP: an in vivo assay

Area of Science:

• Genetics
• Molecular Biology
• Epigenetics

Background:

• Understanding allele-specific protein-DNA interactions is crucial for deciphering the functional impact of genetic variations in non-coding DNA on gene expression.
• Genetic variations, particularly single-nucleotide polymorphisms (SNPs), can influence gene regulation by altering protein binding affinities.

Purpose of the Study:

• To introduce and validate the haplotype-specific chromatin immunoprecipitation (haploChIP) method for analyzing allele-specific protein-DNA interactions.
• To demonstrate the utility of haploChIP in resolving differences in protein occupancy and gene expression between specific DNA haplotypes.

Main Methods:

• The haploChIP technique involves immunoprecipitating proteins crosslinked to DNA in living cells.
• Heterozygous single-nucleotide polymorphisms (SNPs) are utilized as markers to distinguish between different allelic origins.
• Antibodies targeting phosphorylated RNA Polymerase II (Pol II) are employed to assess differences in relative gene expression.

Main Results:

• The haploChIP method successfully differentiates protein-DNA binding at an allele-specific level.
• Relative protein occupancy on specific haplotypes can be resolved, allowing for the testing of hypotheses regarding transcription factor binding.
• Screening of haplotypes for differential gene expression is achievable using haploChIP with antibodies to phosphorylated Pol II.

Conclusions:

• HaploChIP is an effective approach for characterizing allele-specific protein-DNA interactions in living cells.
• This method provides insights into how genetic variations influence protein occupancy and gene regulation at the haplotype level.
• HaploChIP facilitates the study of functional consequences of genetic variation in non-coding DNA.