Fosforilatsioon
Fosforilatsioon is a biochemical process in which a phosphate group is added to a molecule, typically a protein or nucleotide, through the formation of a phosphoester bond. This process is catalyzed by enzymes known as kinases, which transfer a phosphate group from a donor molecule, usually ATP (adenosine triphosphate), to a specific acceptor molecule. The addition of a phosphate group can alter the structure, function, or stability of the target molecule. For example, in signal transduction pathways, fosforilatsioon can activate or deactivate enzymes, leading to changes in cellular processes such as gene expression, cell division, and metabolism. The reverse process, where a phosphate group is removed, is called defosforilatsioon and is catalyzed by phosphatases. Fosforilatsioon plays a crucial role in various biological processes, including cell signaling, cell cycle regulation, and gene transcription. Abnormal fosforilatsioon has been linked to several diseases, such as cancer and neurodegenerative disorders. Understanding the mechanisms and regulation of fosforilatsioon is essential for developing targeted therapies for these conditions.