Structure of synaptophysin: a hexameric MARVEL-domain channel protein.
Synaptophysin I (SypI) is an archetypal member of the MARVEL-domain family of integral membrane proteins and one of the first synaptic vesicle proteins to be identified and cloned. Most all MARVEL-domain proteins are involved in membrane apposition and vesicle-trafficking events, but their precise role in these processes is unclear. We have purified mammalian SypI and determined its three-dimensional (3D) structure by using electron microscopy and single-particle 3D reconstruction. The hexameric structure resembles an open basket with a large pore and tenuous interactions within the cytosolic domain. The structure suggests a model for Synaptophysin's role in fusion and recycling that is regulated by known interactions with the SNARE machinery. This 3D structure of a MARVEL-domain protein provides a structural foundation for understanding the role of these important proteins in a variety of biological processes.
Arthur
Christopher P
CP
MCD Biology, University of Colorado, Boulder, CO 80309, USA.
Stowell
Michael H B
MH
D020816:Amino Acid Motifs; D000595:Amino Acid Sequence; D000818:Animals; D001923:Brain Chemistry; D002417:Cattle; D019281:Dimerization; D007473:Ion Channels / Q000737:chemistry*; D026901:Membrane Transport Proteins / Q000737:chemistry*; D008954:Models, Biological; D008958:Models, Molecular; D009185:Myelin Proteins / Q000737:chemistry*; D062806:Myelin and Lymphocyte-Associated Proteolipid Proteins; D011487:Protein Conformation; D017433:Protein Structure, Secondary; D017434:Protein Structure, Tertiary; D011510:Proteolipids / Q000737:chemistry*; D017386:Sequence Homology, Amino Acid; D013572:Synaptic Vesicles / Q000737:chemistry; D016708:Synaptophysin / Q000737:chemistry* / Q000235:genetics / Q000302:isolation & purification / Q000648:ultrastructure
D007473:Ion Channels; D026901:Membrane Transport Proteins; D009185:Myelin Proteins; D062806:Myelin and Lymphocyte-Associated Proteolipid Proteins; D011510:Proteolipids; D016708:Synaptophysin