Signaling by the Hematopoietic Cytokine Receptors

This book is about cytokines, their receptors and especially about the mechanisms cytokine receptors employ to transduce their crucial biological activities. A central feature for these receptors is the lack of tyrosine kinase domains in their cytoplasmic domain, though induction of tyrosine phosphorylation is absolutely required for their biological effects. Recent discoveries on cytokine receptor signaling mechanisms explain this paradigm. Cytokine receptors are associated with cytoplasmic Jak tyrosine kinases which are activated following ligand binding and transduce the activation signal by phosphorylating substrate proteins. Importantly, Jak kinases phosphorylate and activate members of the STAT transcription factor family and thereby connect cytokine receptor activation to regulation of gene expression.