Does histone phosphorylation increase or decrease gene expression?

In addition to recruitment of histone demethylase(s), histone phosphorylation is thought to facilitate gene expression by structural relaxation of chromatin via neutralization of positive charge on histone proteins, reducing their affinity for DNA and generating a DNA structure permissive for transcription.

What phosphorylates H3?

Meiotic phosphorylation of histone H3 At meiosis, as in mitosis, a specific spacio-temporal phosphorylation of histone H3 at serine 10 was detected. In Tetrahymena, upon micronuclei entering in metaphase of meiosis I histone H3 is phosphorylated, and subsequently dephosphorylated at anaphase (Wei et al., 1998).

What is histone H3?

Histone H3 is one of the five main histones involved in the structure of chromatin in eukaryotic cells. Featuring a main globular domain and a long N-terminal tail, H3 is involved with the structure of the nucleosomes of the ‘beads on a string’ structure.

Are histones found in chromosomes?

Figure 1: Chromosomes are composed of DNA tightly-wound around histones. Chromosomal DNA is packaged inside microscopic nuclei with the help of histones. These are positively-charged proteins that strongly adhere to negatively-charged DNA and form complexes called nucleosomes.

How many types of histones are there?

DNA strands wrap around proteins called histones, which are composed into structures called nucleosomes. There are four types of histones, named: H2A, H2B, H3, and H4.

What happens when H3 is acetylated?

A model proposed that the acetylation of H3 histones activates gene transcription by attracting other transcription related complexes. Therefore, the acetyl mark provides a site for protein recognition where transcription factors interact with the acetylated histone tails via their bromodomain.

What is the role of histone H3S10 phosphorylation?

One of them is the phosphorylation of serine 10 on histone H3 (H3S10ph). H3S10ph is emerging as an important player in the initiation and propagation of cancer, as it facilitates cellular malignant transformation and participates in fundamental cellular functions.

How is h3s10ph phosphorylated in metaphase chromosomes?

Since highly condensed metaphase chromosomes are heavily H3S10 phosphorylated in most organisms analyzed thus far, increased H3S10ph was proposed a distinctive mark for dividing cells [ 11, 31 ].

Why is h3s10ph important in the epigenome?

H3S10ph and enzymes responsible for deposition of this histone modification are important for chromatin activity and oncogenesis. Epigenetic-drugs targeting this axis of modifications, potentially in combination with conventional or targeted therapy, provide a promising angle in search for knowledge-driven therapeutic strategies in oncology.

Is the h3s10ph mark erased during mitosis?

In contrast to other modifications of H3 tail like H3K9me2 or H3K9ac, H3S10ph mark does not become erased as cell enters mitosis [ 27 ], but its abundance increases during cell division, compared to the interphase [ 28, 29 ]. High H3S10ph occupancy along the entire length of chromosomal arms is typically observed in prophase and metaphase.