PMID: 18775332

 

    Legend: Sugar

Title : Structural organization of a full-length gp130 / LIF-R cytokine receptor transmembrane complex

Abstract :

1. gp130 is a shared receptor for at least nine cytokines and can signal either as a homodimer or as a heterodimer with Leukemia Inhibitory Factor Receptor ( LIF-R )
2. Here, we biophysically and structurally characterize the full-length, transmembrane form of a quaternary cytokine receptor complex consisting of gp130 , LIF-R , the cytokine Ciliary Neurotrophic Factor ( CNTF ), and its alpha receptor ( CNTF-Ralpha )
3. Thermodynamic analysis indicates that, unlike the cooperative assembly of the symmetric gp130 / Interleukin-6 / IL-6Ralpha hexameric complex, CNTF / CNTF-Ralpha heterodimerizes gp130 and LIF-R via noncooperative energetics to form an asymmetric 1:1:1:1 complex
4. Single particle electron microscopic analysis of the full-length gp130 / LIF-R / CNTF-Ralpha / CNTF quaternary complex elucidates an asymmetric structural arrangement, in which the receptor extracellular and transmembrane segments join as a continuous, rigid unit, poised to sensitively transduce ligand engagement to the membrane-proximal intracellular signaling regions
5. These studies also enumerate the organizing principles for assembly of the "tall" class of gp130 family cytokine receptor complexes including LIF , IL-27 , IL-12 , and others