Adenosine Diphosphate Ribose (ADP-ribose) is a nucleotide derivative that plays a crucial role in cellular processes, particularly in the regulation of cell signaling and metabolism. It is composed of three main components: adenosine, diphosphate (ADP), and ribose.
Adenosine represents one of the four nucleobases found in RNA, and it provides the molecular backbone for ADP-ribose. Diphosphate refers to the presence of two phosphate groups, which are essential for energy transfer within cells. Ribose is a sugar molecule that acts as the primary building block for the nucleotide.
ADP-ribose functions as a signaling molecule involved in various cellular processes, including DNA repair, calcium signaling, and regulation of transcription factors. It is synthesized through the enzymatic activity of specific proteins known as poly(ADP-ribose) polymerases (PARPs), which add ADP-ribose units to target proteins.
Once synthesized, ADP-ribose can be attached to different amino acid residues in proteins, forming poly(ADP-ribose) chains. These chains serve as platforms for the recruitment of other proteins involved in DNA repair, chromatin remodeling, and gene expression.
Furthermore, ADP-ribose can be cleaved to release the ADP-ribose molecule or further modified by additional enzymes, such as ADP-ribose hydrolases and ADP-ribosyltransferases, which in turn regulate the activity of target proteins.
Overall, adenosine diphosphate ribose is an important molecule involved in diverse cellular processes, functioning as a mediator of protein-protein interactions, intracellular signaling, and regulation of key biological functions.
