Histone H2AX

Paper Summary:

In this article, the writer explains that in the study of biology, histones are the main, large, organic compounds made of amino acids that are considered to be among the most important elements of chromatin. Chromatin is the compound and compact form of deoxyribonucleic acid (DNA) in the nucleus that makes up chromosomes. The paper studies one of the major and core histones, the DNA that wraps the nucleosome around two copies each of histone proteins, the H2AX and focuses on histone as a gene or protein in the aquatic environment. The paper also discusses that histone H2AX is characterized by having a long terminal tail on one end of the amino acid structure and that this feature is the main difference from H2A.

From the Paper:

"Once the DNA is damaged and its physiology is disturbed in normal healthy individual, the p53 protein or TP53 is activated and can start a cell cycle arrest. The tail of H2XA, also known as the carboxy terminus, rapidly becomes labeled with phosphate groups that generate species called gamma-H2AX. This protein functions as a tumor suppressor and protects the genes as it is closely controlled by phosphorylation. The phosphorylated histone H2AX cooperates in repairing the genetic damage. It preserves the stability of the cells and prevents the onset of tumors. In DNA repair, chromatic reorganization plays an important role. Chromatin is responsible in packaging the DNA into a smaller volume for it to fit in the cell. This process aims to strengthen the DNA to allow mitosis and meiosis, where the cells divides and separates into two identical sets. This is also vital in apoptosis, cell cycle checkpoints, and serves as a mechanism to control inheritable information from a gene. The H2AX histone phosphorylation kinetics correlated well with the kinetics of DNA-adducts removal at earlier recovery time points. The chromatin reorganization is composed of proteins that are involved in the process."

Sample of Sources Used:

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