Histone H2AX in DNA repair
نویسندگان
چکیده
In eucaryotic cells, DNA is bound to various proteins and forms a complex nucleoprotein structure called chromatin. Indispensable and ubiquitous chromatin components are histones, small proteins of highly conserved primary structure. Two molecules of each H2A, H2B, H3 and H4 type, form the nucleosomal core around which a 146 base pair (bp) stretch of DNA is wrapped. Histone H1 is bound to about 40 bp linker DNA. A sketch of the nucleosomal core structure is shown in Fig. 1. The repeats of this unit structure together with the linker region form the so-called beads on a string, that can be seen on photographs of relaxed chromatin in an electron microscope.
منابع مشابه
Expression of phosphorylated histone H2AX in blood lymphocytes of patients undergoing angiographic procedures following exposure to X‐rays
Introduction: Coronary angiography is a Diagnostic-Therapeutic method involving ionizing radiation. This method causes to DNA damage with form double stranded breaks which is followed by the phosphorylation of the histone, H2AX. H2AX is a key factor in the repair process of damaged DNA which will accumulate to damage sites. In human cells, H2AX constitutes about 10% of the H2A ...
متن کاملEvaluating Gamma-H2AX Expression as a Biomarker of DNA Damage after X-ray in Angiography Patients
Objective: Coronary heart disease (CHD) is one of the most common diseases. Coronary angiography (CAG) is an important apparatus used to diagnose and treat this disease. Since angiography is performed through exposure to ionizing radiation, it can cause harmful effects induced by double-stranded breaks in DNA which is potentially life-threatening damage. The aim of the present study is to inves...
متن کاملCritical role of lysine 134 methylation on histone H2AX for γ-H2AX production and DNA repair
The presence of phosphorylated histone H2AX (γ-H2AX) is associated with the local activation of DNA-damage repair pathways. Although γ-H2AX deregulation in cancer has previously been reported, the molecular mechanism involved and its relationship with other histone modifications remain largely unknown. Here we find that the histone methyltransferase SUV39H2 methylates histone H2AX on lysine 134...
متن کاملDNA Repair: The Importance of Phosphorylating Histone H2AX
How phosphorylated histone H2AX, known as gamma-H2AX, functions in the cellular response to DNA double-strand breaks is the subject of intensive investigation. Recent research in yeast and mammalian cells shows that gamma-H2AX facilitates post-replicational DNA repair by recruiting cohesin, a protein complex that holds sister chromatids together.
متن کاملA PP4-phosphatase complex dephosphorylates gamma-H2AX generated during DNA replication.
The histone H2A variant H2AX is rapidly phosphorylated in response to DNA double-stranded breaks to produce gamma-H2AX. gamma-H2AX stabilizes cell-cycle checkpoint proteins and DNA repair factors at the break site. We previously found that the protein phosphatase PP2A is required to resolve gamma-H2AX foci and complete DNA repair after exogenous DNA damage. Here we describe a three-protein PP4 ...
متن کاملγ-H2AX as a protein biomarker for radiation exposure response in ductal carcinoma breast tumors: Experimental evidence and literature review
Background: H2AX is a histone variant that is systematically found and ubiquitously distributed throughout the genome. DNA double-strand breaks (DSBs) induce phosphorylation of H2AX at serine 139 (γH2AX), an immunocytochemical assay with antibodies recognizing γH2AX has become the gold standard for the detection of DSBs. The importance of this assay to investigate different individu...
متن کامل