Interaction of synaptotagmin with the cytoplasmic domains of neurexins.
Synaptotagmin, a major intrinsic membrane protein of synaptic vesicles that binds Ca2+, was purified from bovine brain and immobilized onto Sepharose 4B. Affinity chromatography of brain membrane proteins on immobilized synaptotagmin revealed binding of alpha- and beta-neurexins to synaptotagmin in a Ca(2+)-independent manner. Using a series of recombinant proteins in which glutathione S-transferase was fused to the cytoplasmic domains of three different neurexins or of control proteins, it was found that synaptotagmin specifically interacts with the cytoplasmic domains of neurexins but not of control proteins. This interaction is dependent on a highly conserved, 40 amino acid sequence that makes up most of the cytoplasmic tails of the neurexins. Our data suggest a direct interaction between the cytoplasmic domains of a plasma membrane protein (the neurexins) and a protein specific for a subcellular organelle (synaptotagmin). Such an interaction could have an important role in the docking and targeting of synaptic vesicles in the nerve terminal.
Hata
Y
Y
Howard Hughes Medical Institute, University of Texas, Southwestern Medical Center, Dallas 75235.
Davletov
B
B
Petrenko
A G
AG
Jahn
R
R
Südhof
T C
TC
D000595:Amino Acid Sequence; D000818:Animals; D001665:Binding Sites; D001923:Brain Chemistry; D002135:Calcium-Binding Proteins; D002417:Cattle; D002462:Cell Membrane / Q000737:chemistry; D002846:Chromatography, Affinity; D003593:Cytoplasm / Q000378:metabolism*; D005982:Glutathione Transferase / Q000235:genetics; D015151:Immunoblotting; D007163:Immunosorbent Techniques; D008562:Membrane Glycoproteins / Q000302:isolation & purification / Q000378:metabolism*; D008565:Membrane Proteins / Q000302:isolation & purification / Q000378:metabolism; D008969:Molecular Sequence Data; D009419:Nerve Tissue Proteins / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism*; D011950:Receptors, Cholinergic / Q000378:metabolism; D018000:Receptors, Peptide; D011993:Recombinant Fusion Proteins / Q000737:chemistry / Q000378:metabolism; D013572:Synaptic Vesicles / Q000737:chemistry; D050857:Synaptotagmins
D002135:Calcium-Binding Proteins; D008562:Membrane Glycoproteins; D008565:Membrane Proteins; D009419:Nerve Tissue Proteins; D011950:Receptors, Cholinergic; D018000:Receptors, Peptide; D011993:Recombinant Fusion Proteins; C034800:alpha-latrotoxin receptor; D050857:Synaptotagmins; D005982:Glutathione Transferase