How calcium makes endocytic receptors attractive.
Nutrients, biological waste-products, toxins, pathogens, and other ligands for endocytosis are typically captured by multidomain receptors with multiligand specificity. Upon internalization, the receptor-ligand complex segregates, followed by lysosomal degradation of the ligand and recycling of the receptor. Endosomal acidification and calcium efflux lead to the essential ligand-receptor affinity switch and separation. Recent data, including crystal structures of receptor-ligand complexes, now reveal how calcium, in different types of domain scaffolds, functions in a common way as a removable 'lynchpin' that stabilizes favorable positioning of ligand-attractive receptor residues. In addition to explaining how calcium depletion can cause ligand-receptor dissociation, the new data add further insight into how acidification contributes to dissociation through structural changes that affect the receptor calcium sites.
['Andersen|Christian B F|CB|', 'Moestrup|Søren K|SK|']
D000818:Animals D001692:Biological Transport D002118:Calcium D020013:Calcium Signaling D004705:Endocytosis D011992:Endosomes D005057:Eukaryotic Cells D005786:Gene Expression Regulation D006801:Humans D006863:Hydrogen-Ion Concentration D008024:Ligands D008958:Models, Molecular D011485:Protein Binding D017434:Protein Structure, Tertiary D011956:Receptors, Cell Surface
C-type lectin CUB EGF-like LDL receptor scavenger receptor