Download MendeleyStructure of a Janus kinase cytokine receptor complex reveals the basis for dimeric activation.
Glassman, C.R., Tsutsumi, N., Saxton, R.A., Lupardus, P.J., Jude, K.M., Garcia, K.C.(2022) Science 376: 163-169
- PubMed: 35271300
- DOI: https://doi.org/10.1126/science.abn8933
- Primary Citation of Related Structures:
7T6F - PubMed Abstract:
Cytokines signal through cell surface receptor dimers to initiate activation of intracellular Janus kinases (JAKs). We report the 3.6-angstrom-resolution cryo-electron microscopy structure of full-length JAK1 complexed with a cytokine receptor intracellular domain Box1 and Box2 regions captured as an activated homodimer bearing the valine→phenylalanine (VF) mutation prevalent in myeloproliferative neoplasms. The seven domains of JAK1 form an extended structural unit, the dimerization of which is mediated by close-packing of the pseudokinase (PK) domains from the monomeric subunits. The oncogenic VF mutation lies within the core of the JAK1 PK interdimer interface, enhancing packing complementarity to facilitate ligand-independent activation. The carboxy-terminal tyrosine kinase domains are poised for transactivation and to phosphorylate the receptor STAT (signal transducer and activator of transcription)-recruiting motifs projecting from the overhanging FERM (four-point-one, ezrin, radixin, moesin)-SH2 (Src homology 2)-domains. Mapping of constitutively active JAK mutants supports a two-step allosteric activation mechanism and reveals opportunities for selective therapeutic targeting of oncogenic JAK signaling.
Organizational Affiliation:
Department of Molecular and Cellular Physiology, Stanford University School of Medicine, Stanford, CA 94305, USA.
