RRC ID 6656
Author Weidenhaupt M, Bruckert F, Louwagie M, Garin J, Satre M.
Title Functional and molecular identification of novel members of the ubiquitous membrane fusion proteins alpha- and gamma-SNAP (soluble N-ethylmaleimide-sensitive factor-attachment proteins) families in Dictyostelium discoideum.
Journal Eur J Biochem
Abstract The soluble N-ethylmaleimide-sensitive-factor-attachment proteins (SNAP) are eukaryotic soluble proteins required for membrane fusion. Based on their initial identification in bovine brain cytosol, they are divided in alpha/beta and gamma subfamilies. SNAPs act as adapters between N-ethylmaleimide-sensitive factor (NSF), a hexameric ATPase, and membrane SNARE proteins (SNAP receptors). Within the NSF/SNAP/SNARE complex, SNAPs contribute to the catalysis of an ATP-driven conformational change in the SNAREs, resulting in dissociation of the complex. We have constructed a Dictyostelium discoideum strain overexpressing a c-myc-tagged form of D. discoideum NSF (NSF-myc). Its immunoprecipitation from detergent-solubilized membrane extracts reveals two associated polypeptides with apparent molecular masses of 33 and 36 kDa (p33 and p36) that are absent in NSF-myc immunoprecipitates from cytosol. Analysis of trypsin-digested peptides by microsequencing and mass spectrometry and comparison with cDNA sequences identify p33 and p36 as the D. discoideum homologues of alpha- and gamma-SNAP, respectively. The alpha-/gamma-SNAP molar ratio is close to 3 in vegetative amoebae from this organism. The molecular identification of gamma-SNAP in plants (Arabidopsis thaliana) and insects (Drosophila melanogaster) documents, for the first time, the wide distribution of the gamma subtype. Altogether, these results suggest a specific role for gamma-SNAP, distinct from that of alpha-SNAP.
Volume 267(7)
Pages 2062-70
Published 2000-4-1
DOI 10.1046/j.1432-1327.2000.01212.x
PII ejb1212
PMID 10727946
MeSH Amino Acid Sequence Animals Carrier Proteins / chemistry Carrier Proteins / genetics Carrier Proteins / metabolism* Dictyostelium / genetics Dictyostelium / metabolism* Humans Membrane Proteins / chemistry Membrane Proteins / genetics Membrane Proteins / metabolism* Molecular Sequence Data Phylogeny Plasmids Protein Structure, Secondary Proto-Oncogene Proteins c-myc / metabolism Sequence Homology, Amino Acid Soluble N-Ethylmaleimide-Sensitive Factor Attachment Proteins Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization Vesicular Transport Proteins*
Times Cited 15
Cellular slime molds G02305