title: VAMP subfamilies identified by specific R-SNARE motifs.
abstract: In eukaryotes, interactions among the alpha-helical coiled-coil domains (CCDs) of soluble N-ethylmaleimide-sensitive factor attachment protein receptors (SNAREs) play a pivotal role in mediating the fusion among vesicles and target membranes. Surface residues of such CCDs are major candidates to regulate the specificity of membrane fusion, as they may alter local charge at the interaction layers and surface of the fusion complex, possibly modulating its formation and/or the binding of non-SNARE regulatory factors. Based on alternate patterns in surface residues, we have identified two motifs which group vesicular SNAREs in two novel subfamilies: RG-SNAREs and RD-SNAREs. The RG-SNARE CCD is common to all members of the widely conserved family of long VAMPs or longins and to yeast and non-neuronal VAMPs, possibly mediating "basic" fusion mechanisms; instead, only synaptobrevins from Bilateria share an RD-SNARE CCD, which is likely to mediate interactions to specific, yet unknown, regulatory factors and/or be the landmark of rapid fusion reactions like that mediating the release of neurotransmitters.
authors.affiliation: Department of Biology, University of Padua, 35131 Padova, Italy.
authors.forename: Valeria
authors.initials: V
authors.lastname: Rossi
authors.forename: Raffaella
authors.initials: R
authors.lastname: Picco
authors.forename: Marcella
authors.initials: M
authors.lastname: Vacca
authors.forename: Maurizio
authors.initials: M
authors.lastname: D'Esposito
authors.forename: Michele
authors.initials: M
authors.lastname: D'Urso
authors.forename: Thierry
authors.initials: T
authors.lastname: Galli
authors.forename: Francesco
authors.initials: F
authors.lastname: Filippini
mesh_terms: D020816:Amino Acid Motifs / Q000235:genetics; D000595:Amino Acid Sequence / Q000235:genetics; D019943:Amino Acid Substitution / Q000235:genetics; D000818:Animals; D016384:Consensus Sequence / Q000235:genetics; D017124:Conserved Sequence / Q000235:genetics; D005057:Eukaryotic Cells / Q000737:chemistry; D019143:Evolution, Molecular; D006801:Humans; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D017434:Protein Structure, Tertiary; D050600:SNARE Proteins; D017386:Sequence Homology, Amino Acid; D052067:Soluble N-Ethylmaleimide-Sensitive Factor Attachment Proteins; D033921:Vesicular Transport Proteins / Q000737:chemistry* / Q000235:genetics
chemical_list: D050600:SNARE Proteins; D052067:Soluble N-Ethylmaleimide-Sensitive Factor Attachment Proteins; D033921:Vesicular Transport Proteins