Structural analysis uncovers lipid-binding properties of Notch ligands.
The Notch pathway is a core cell-cell signaling system in metazoan organisms with key roles in cell-fate determination, stem cell maintenance, immune system activation, and angiogenesis. Signals are initiated by extracellular interactions of the Notch receptor with Delta/Serrate/Lag-2 (DSL) ligands, whose structure is highly conserved throughout evolution. To date, no structure or activity has been associated with the extreme N termini of the ligands, even though numerous mutations in this region of Jagged-1 ligand lead to human disease. Here, we demonstrate that the N terminus of human Jagged-1 is a C2 phospholipid recognition domain that binds phospholipid bilayers in a calcium-dependent fashion. Furthermore, we show that this activity is shared by a member of the other class of Notch ligands, human Delta-like-1, and the evolutionary distant Drosophila Serrate. Targeted mutagenesis of Jagged-1 C2 domain residues implicated in calcium-dependent phospholipid binding leaves Notch interactions intact but can reduce Notch activation. These results reveal an important and previously unsuspected role for phospholipid recognition in control of this key signaling system.
Department of Biochemistry, University of Oxford, South Parks Road, Oxford OX1 3QU, UK.
Chandramouli R
CR
Chillakuri
Devon
D
Sheppard
Ma Xenia G
MX
Ilagan
Laurie R
LR
Holt
Felicity
F
Abbott
Shaoyan
S
Liang
Raphael
R
Kopan
Penny A
PA
Handford
Susan M
SM
Lea
D000595:Amino Acid Sequence; D002118:Calcium / Q000737:chemistry; D002135:Calcium-Binding Proteins / Q000235:genetics / Q000378:metabolism* / Q000648:ultrastructure; D002454:Cell Differentiation / Q000235:genetics; D002460:Cell Line; D018360:Crystallography, X-Ray; D029721:Drosophila Proteins; D004789:Enzyme Activation / Q000235:genetics; D050556:Fatty Acid-Binding Proteins / Q000378:metabolism* / Q000648:ultrastructure; D057809:HEK293 Cells; D006801:Humans; D036341:Intercellular Signaling Peptides and Proteins / Q000235:genetics / Q000378:metabolism*; D000072100:Jagged-1 Protein; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism* / Q000648:ultrastructure; D008969:Molecular Sequence Data; D010743:Phospholipids / Q000378:metabolism; D017434:Protein Structure, Tertiary; D051880:Receptors, Notch / Q000378:metabolism; D016415:Sequence Alignment; D000072099:Serrate-Jagged Proteins; D015398:Signal Transduction / Q000235:genetics
D002135:Calcium-Binding Proteins; C512941:DLK1 protein, human; D029721:Drosophila Proteins; D050556:Fatty Acid-Binding Proteins; D036341:Intercellular Signaling Peptides and Proteins; C000606273:JAG1 protein, human; D000072100:Jagged-1 Protein; D008565:Membrane Proteins; D010743:Phospholipids; D051880:Receptors, Notch; C000606278:Ser protein, Drosophila; D000072099:Serrate-Jagged Proteins; D002118:Calcium