摘要
Protein kinases and protein phosphatases play key roles in regulating functions of diverse proteins which control
Protein kinases and protein phosphatases play key roles in regulating functions of diverse proteins which control numerous essential events in eukaryotes, such as transcriptional regulation, apoptosis, cell cycle progression, protein degradation and protein trafficking. Protein kinases transfer a phosphate from ATP to a specific residue(s), typically at serine, threonine, or tyrosine, in proteins, while phosphatases remove phosphoryl groups from proteins. Such a phosphorylation-dephosphorylation cycle can be regarded as a molecular "on-off" switch. It is estimated that the human genome contains over 2,000 kinases and 1,000 phosphatases. A very large number of protein kinases has been identified and studied in detail, and more and more, information concerning protein phosphatases has emerged recently.