LDLR class B repeat / Low-density lipoprotein-receptor YWTD domain / Tyrosine-protein kinase, receptor class II, conserved site / Receptor tyrosine kinase class II signature. / Six-bladed beta-propeller, TolB-like / Fibronectin type III domain / : / Fibronectin type 3 domain / Fibronectin type-III domain profile. / Fibronectin type III ...LDLR class B repeat / Low-density lipoprotein-receptor YWTD domain / Tyrosine-protein kinase, receptor class II, conserved site / Receptor tyrosine kinase class II signature. / Six-bladed beta-propeller, TolB-like / Fibronectin type III domain / : / Fibronectin type 3 domain / Fibronectin type-III domain profile. / Fibronectin type III / Fibronectin type III superfamily / Tyrosine-protein kinase, catalytic domain / Tyrosine kinase, catalytic domain / Tyrosine protein kinases specific active-site signature. / Tyrosine-protein kinase, active site / Serine-threonine/tyrosine-protein kinase, catalytic domain / Protein tyrosine and serine/threonine kinase / Protein kinase, ATP binding site / Protein kinases ATP-binding region signature. / Immunoglobulin-like fold / Protein kinase domain profile. / Protein kinase domain / Protein kinase-like domain superfamily 類似検索 - ドメイン・相同性
ジャーナル: Nat Commun / 年: 2025 タイトル: Structural basis for the interaction between the Drosophila RTK Sevenless (dROS1) and the GPCR BOSS. 著者: Jianan Zhang / Yuko Tsutsui / Hengyi Li / Tongqing Li / Yueyue Wang / Salma Laraki / Sofia Alarcon-Frias / Steven E Stayrook / Daryl E Klein / 要旨: Sevenless, the Drosophila homologue of ROS1 (University of Rochester Sarcoma) (herein, dROS1) is a receptor tyrosine kinase (RTK) essential for the differentiation of Drosophila R7 photoreceptor ...Sevenless, the Drosophila homologue of ROS1 (University of Rochester Sarcoma) (herein, dROS1) is a receptor tyrosine kinase (RTK) essential for the differentiation of Drosophila R7 photoreceptor cells. Activation of dROS1 is mediated by binding to the extracellular region (ECR) of the GPCR (G protein coupled receptor) BOSS (Bride Of Sevenless) on adjacent cells. Activation of dROS1 by BOSS leads to subsequent downstream signaling pathways including SOS (Son of Sevenless). However, the physical basis for how dROS1 interacts with BOSS has long remained unknown. Here we provide a cryo-EM structure of dROS1's extracellular region, which mediates ligand binding. We show that the extracellular region of dROS1 adopts a folded-over conformation stabilized by an N-terminal domain comprised of two disulfide stapled helical hairpins. We further narrowed down the interacting binding epitopes on both dROS1 and BOSS using hydrogen-deuterium exchange mass spectrometry (HDX-MS). This includes beta-strands in dROS1's third Fibronectin type III (FNIII) domain and a C-terminal peptide in BOSS' ECR. Our mutagenesis studies, coupled with AlphaFold complex predictions, support a binding interaction mediated by a hydrophobic interaction and beta-strand augmentation between these regions. Our findings provide a fundamental understanding of the regulatory function of dROS1 and further provide mechanistic insight into the human ortholog and oncogene ROS1.