A novel family of growth factor receptors: a common binding domain in the growth hormone, prolactin, erythropoietin and IL-6 receptors, and the p75 IL-2 receptor beta-chain.
Lymphokine and hematopoietic growth factors control the differentiation and proliferation of diverse cell types by binding to specific cell-surface receptors. Strikingly, the recently elucidated sequences of the interleukin-6 and erythropoietin receptors, and the interleukin-2 receptor beta-chain (p75), display a significant evolutionary resemblance of their extracellular domains. This homology extends to the binding domains of the growth hormone/prolactin class of receptors. Alternatively, little similarity exists between the cytoplasmic extensions of these diverse receptors. I discuss the evolutionary and functional implications of this broad, mosaic receptor relationship, with particular reference to possible structural resemblances between the cognate growth factors.
Bazan
J F
JF
Department of Biochemistry and Biophysics, University of California, San Francisco 94143-0448.
D000595:Amino Acid Sequence; D000818:Animals; D004921:Erythropoietin / Q000378:metabolism; D006801:Humans; D015850:Interleukin-6 / Q000502:physiology; D046911:Macromolecular Substances; D051379:Mice; D008969:Molecular Sequence Data; D011817:Rabbits; D011956:Receptors, Cell Surface / Q000235:genetics*; D017467:Receptors, Erythropoietin; D011971:Receptors, Immunologic / Q000235:genetics*; D015375:Receptors, Interleukin-2 / Q000235:genetics; D019947:Receptors, Interleukin-6; D011981:Receptors, Prolactin / Q000235:genetics; D011986:Receptors, Somatotropin / Q000235:genetics; D012689:Sequence Homology, Nucleic Acid
D015850:Interleukin-6; D046911:Macromolecular Substances; D011956:Receptors, Cell Surface; D017467:Receptors, Erythropoietin; D011971:Receptors, Immunologic; D015375:Receptors, Interleukin-2; D019947:Receptors, Interleukin-6; D011981:Receptors, Prolactin; D011986:Receptors, Somatotropin; D004921:Erythropoietin