Eucaryote signals-regulated protein

Of particular importance is the phosphorylation of eucaryotic transcription factors. Functional and mechanistic consequences of the phosphorylation of transcription factors will be discussed in more detail in the section on the regulation of eucaryotic transcription (see 1.4.3.2). Specific or non-specific protein phosphatases (see 7.5) can remove the phosphate residues and terminate the phosphorylation signal. 

The phosphorylation of proteins on Ser, Thr or Tyr residues is a basic tool for the regulation of protein activity (see 7.1). Many eucaryotic transcriptional activators are isolated as phosphorylated proteins. The phosphorylation occurrs mainly on the Ser and Thr residues, but can also be observed on the Tyr residues. The extent of phosphorylation is regulated via specific protein kinases and protein phosphatases, each components of signal transduction pathways (see ch. 7). The phosphorylation of transcriptio-... 

The phosphorylation of enzymes by specific protein kinases is a widespread mechanism for the regulation of enzyme activity. It represents a flexible and reversible means of regulation and plays a central role in signal transduction chains in eucaryotes. 

---