[Classification of cytokine receptor superfamily and signal transduction--structural feature and functional property]

Abstract

Cytokines are groups of protein mediators that are involved in cell to cell communication and are classified into several distinct families based on their receptor structures. The class I cytokine receptor family includes most of interleukins and colony stimulating factors receptors and shares a conserved extracellular motif with homology to the fibronectin type III domain. While they do not have any intrinsic enzymatic activity, they bind a member of JAK family kinases. The receptors form a homo- or hetero-multimer by cytokine binding and activate the JAKs associated with the receptor. There are some groups of cytokines which exhibit similar functions by sharing the same receptor subunit.