title: A region encompassing the FERM domain of Jak1 is necessary for binding to the cytokine receptor gp130.
abstract: The terminal portion of the Janus kinases (Jaks) contains a divergent FERM (Four-point-one, Ezrin, Radixin, Moesin) homology domain comprising 19 conserved hydrophobic regions. To determine the role of this domain in governing recruitment of Jak1, but not Jak3, to the gp130 subunit of the interleukin-6 family of cytokine receptors, the interaction of three Jak1/Jak3 chimeras with gp130 was investigated. Chimeras 1, 2 and 3 (Jak1 FERM regions 1-19, 1-18 and 1-8/Jak3, respectively) were all enzymically active. Chimeras 1 and 2 interacted with the cytoplasmic domain of gp130, although less efficiently than Jak1. Only chimera 2, however, restored gp130 signalling in Jak1-negative cells. The data are consistent with recruitment of Jak1 to gp130 through the Jak1 FERM domain, but also emphasise the likely requirement for precise Jak/receptor orientation to sustain function.
authors.affiliation: Imperial Cancer Research Fund, London, UK.
authors.forename: C M
authors.initials: CM
authors.lastname: Hilkens
authors.forename: H
authors.initials: H
authors.lastname: Is'harc
authors.forename: B F
authors.initials: BF
authors.lastname: Lillemeier
authors.forename: B
authors.initials: B
authors.lastname: Strobl
authors.forename: P A
authors.initials: PA
authors.lastname: Bates
authors.forename: I
authors.initials: I
authors.lastname: Behrmann
authors.forename: I M
authors.initials: IM
authors.lastname: Kerr
mesh_terms: D000595:Amino Acid Sequence; D015703:Antigens, CD / Q000378:metabolism*; D001665:Binding Sites; D050822:Cytokine Receptor gp130; D003593:Cytoplasm / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000378:metabolism; D005354:Fibrosarcoma; D006801:Humans; D053613:Janus Kinase 1; D053616:Janus Kinase 3; D008562:Membrane Glycoproteins / Q000378:metabolism*; D008969:Molecular Sequence Data; D017434:Protein Structure, Tertiary; D011505:Protein-Tyrosine Kinases / Q000235:genetics / Q000378:metabolism*; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism; D050794:STAT1 Transcription Factor; D015398:Signal Transduction; D015534:Trans-Activators / Q000378:metabolism; D014407:Tumor Cells, Cultured
chemical_list: D015703:Antigens, CD; D004268:DNA-Binding Proteins; C494199:IL6ST protein, human; D008562:Membrane Glycoproteins; D011994:Recombinant Proteins; D050794:STAT1 Transcription Factor; C494079:STAT1 protein, human; D015534:Trans-Activators; D050822:Cytokine Receptor gp130; D011505:Protein-Tyrosine Kinases; C507904:JAK1 protein, human; C507933:JAK3 protein, human; D053613:Janus Kinase 1; D053616:Janus Kinase 3