Molecular basis of synaptic vesicle cargo recognition by the endocytic sorting adaptor stonin 2.
Synaptic transmission depends on clathrin-mediated recycling of synaptic vesicles (SVs). How select SV proteins are targeted for internalization has remained elusive. Stonins are evolutionarily conserved adaptors dedicated to endocytic sorting of the SV protein synaptotagmin. Our data identify the molecular determinants for recognition of synaptotagmin by stonin 2 or its Caenorhabditis elegans orthologue UNC-41B. The interaction involves the direct association of clusters of basic residues on the surface of the cytoplasmic domain of synaptotagmin 1 and a beta strand within the mu-homology domain of stonin 2. Mutation of K783, Y784, and E785 to alanine within this stonin 2 beta strand results in failure of the mutant stonin protein to associate with synaptotagmin, to accumulate at synapses, and to facilitate synaptotagmin internalization. Synaptotagmin-binding-defective UNC-41B is unable to rescue paralysis in C. elegans stonin mutant animals, suggesting that the mechanism of stonin-mediated SV cargo recognition is conserved from worms to mammals.
Jung
Nadja
N
Department of Membrane Biochemistry, Institute of Chemistry and Biochemistry, Freie Universität Berlin, 14195 Berlin, Germany.
Wienisch
Martin
M
Gu
Mingyu
M
Rand
James B
JB
Müller
Sebastian L
SL
Krause
Gerd
G
Jorgensen
Erik M
EM
Klingauf
Jürgen
J
Haucke
Volker
V
D033942:Adaptor Proteins, Vesicular Transport; D000595:Amino Acid Sequence / Q000502:physiology; D019943:Amino Acid Substitution / Q000502:physiology; D000818:Animals; D017173:Caenorhabditis elegans; D029742:Caenorhabditis elegans Proteins / Q000235:genetics / Q000378:metabolism*; D002460:Cell Line; D017124:Conserved Sequence; D004705:Endocytosis / Q000502:physiology*; D019143:Evolution, Molecular; D006801:Humans; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism*; D009154:Mutation / Q000235:genetics; D009420:Nervous System / Q000378:metabolism* / Q000648:ultrastructure; D017729:Presynaptic Terminals / Q000378:metabolism* / Q000648:ultrastructure; D011485:Protein Binding / Q000502:physiology; D017434:Protein Structure, Tertiary / Q000502:physiology; D021381:Protein Transport / Q000502:physiology; D009435:Synaptic Transmission / Q000502:physiology; D013572:Synaptic Vesicles / Q000378:metabolism* / Q000648:ultrastructure; D050863:Synaptotagmin I / Q000378:metabolism*; D033921:Vesicular Transport Proteins / Q000235:genetics / Q000378:metabolism*
D033942:Adaptor Proteins, Vesicular Transport; D029742:Caenorhabditis elegans Proteins; D008565:Membrane Proteins; C429267:STON2 protein, human; D050863:Synaptotagmin I; C526449:Unc-41 protein, C elegans; D033921:Vesicular Transport Proteins