n. (context genetics English) The set of all kinases expressed in a cell or contained in a genome.
In molecular biology, the kinome of an organism is the set of protein kinases in its genome. Kinases are enzymes that catalyze phosphorylation reactions (of amino acids) and fall into several groups and families, e.g., those that phosphorylate the amino acids serine and threonine, those that phosphorylate tyrosine and some that can phosphorylate both, such as the MAP2K and GSK families. The term was first used in 2002 by Gerard Manning and colleagues in twin papers analyzing the 518 human protein kinases and the evolution of protein kinases throughout eukaryotes. Other kinomes have been determined for rice, several fungi, nematodes, and insects, sea urchins, Dictyostelium discoideum, and the process of infection by Mycobacterium tuberculosis. Although the primary sequence of kinases shows substantial divergence between unrelated eukaryotes, variation in the motifs that are actually phosphorylated by eukaryotic kinases is much smaller.
As kinases are a major drug target and a major control point in cell behavior, the kinome has also been the target of large scale functional genomics with RNAi screens and of drug discovery efforts, especially in cancer therapeutics.
In animals, the kinome includes kinases that phosphorylate only tyrosine (tyrosine kinases), those that act on serine or threonine, and a few classes, such as GSK3 and MAP2K that can act on both. It was long believed that serine/threonine kinases played different metabolic roles than tyrosine kinases, the former being used mainly for inducing conformational changes versus the latter being used to create structural "handles" on proteins that to enable binding by an SH2 domain. However, recent research has shown that there are specialized protein domains that bind to phosphorylated serine and threonine residues, such as BRCA and FHA domains.