Protein phosphorylation is a post-translational modification (PTM) that plays multiple cellular roles. This reversible modification involves the addition of phosphate groups to specific serine, threonine, or tyrosine residues of proteins, mediated by protein kinases and removed by protein phosphatases. Protein phosphorylation has significant implications for epigenetics, gene expression, chromatin structure, and cellular differentiation. One role of protein phosphorylation in epigenetic regulation is in the control of gene transcription. Phosphorylation of transcription factors, co-regulators, and RNA polymerase subunits can each influence their activity and interactions with chromatin. For example, the C-terminal domain (CTD) of RNA polymerase II (RNAP II) can be extensively phosphorylated at specific serine and threonine residues and these phosphorylation events play a role in transcription initiation, elongation, and termination. For example, the kinase CDK7, along with its regulatory cyclin subunit Cyclin H, is a component of the general transcription factor TFIIH which phosphorylates the CTD of RNAP II at serine 5 (Ser5) during the early stages of transcription initiation. Histone phosphorylation is another important aspect of epigenetic regulation. Various kinases target histones, leading to changes in chromatin structure and gene expression. For example, phosphorylation of H3S10 is one of the earliest and most prominent histone modifications during mitosis and is involved in chromatin condensation into compact structures known as chromatids. Phosphorylation of histone H2A.X at serine 139 (γH2A.X) is a well-known marker of DNA damage and is involved in DNA repair processes. Ser 139 phosphorylation is catalysed by ATM (Ataxia Telangiectasia Mutated), a key component of the DNA damage response (DDR) pathway which plays a key role in detecting DNA double-strand breaks (DSBs) and initiating repair responses. Furthermore, protein phosphorylation can regulate the activities of chromatin-modifying enzymes, including histone acetyltransferases (HATs) and histone deacetylases (HDACs). Phosphorylation can either enhance or inhibit their enzymatic activities, leading to alterations in histone acetylation levels and chromatin accessibility. This dynamic regulation of histone acetylation is crucial for controlling gene expression patterns and maintaining epigenetic marks. An additional aspect of protein phosphorylation in epigenetic regulation is its role in DNA methylation. DNA methyltransferases (DNMTs) which add methyl groups to DNA are subject to regulatory phosphorylation. Phosphorylation of DNMTs can positively or negatively modulate their stability, localization, and activity, impacting DNA methylation patterns and gene expression. For example, phosphorylation can enhance DNMT activity by promoting its binding to DNA and increasing its affinity for the substrate, S-adenosylmethionine (SAM). Chromatin remodellers- enzymes responsible for altering chromatin structure – contain subunits also subject to regulatory phosphorylation. For example, CHD proteins, a family of chromatin remodellers that contain chromodomains and helicase domains can be phosphorylated by kinases like CDKs and PKC thereby modulating their activity and affecting their recruitment to specific gene loci. Finally, protein phosphorylation is essential for the regulation of epigenetic marks like DNA hydroxymethylation, which is involved in DNA demethylation processes. Phosphorylation of ten-eleven translocation (TET) enzymes, responsible for DNA hydroxymethylation, can influence their activity, thus affecting the dynamic balance between DNA methylation and demethylation, which is crucial for epigenetic regulation. We provide a comprehensive product catalogue of research tools for studying protein phosphorylation, including Aurora B antibodies, Thymidine Phosphorylase antibodies, and CAMKIV antibodies. Explore our full protein phosphorylation product range below and discover more, for less.