Expression of the synaptic vesicle proteins VAMPs/synaptobrevins 1 and 2 in non-neural tissues.
The VAMPs/synaptobrevins (Vp/Sybs) are small integral membrane proteins. Two isoforms, Vp/Syb 1 and Vp/Syb 2, are considered to be specific to neural tissue. They are associated with synaptic vesicles and are believed to play an important role in neurotransmitter release. A third isoform, cellubrevin, has recently been found in non-neural tissues. We now report that the distribution of Vp/Syb 1 and Vp/Syb 2 is wider than previously thought. RNA transcripts for both Vp/Syb 1 and Vp/Syb 2 were found in rat skeletal muscle and in several other rat non-neural tissues, and antibodies specific for Vp/Syb 2 detected a protein in the endoplasmic reticulum-Golgi area of skeletal muscle. Thus Vp/Sybs 1 and 2 are not restricted to the nervous system but appear to be co-expressed with cellubrevin in many different tissues. This redundancy of Vp/Sybs in a single cell may be required to control the specificity of vesicle-target interaction in the several pathways of intracellular vesicle traffic that are operative within each cell.
Ralston
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E
Laboratory of Neurobiology, NINDS, National Institutes of Health, Bethesda, Maryland 20892.
Beushausen
S
S
Ploug
T
T
D002001:Adipose Tissue, Brown / Q000378:metabolism*; D000595:Amino Acid Sequence; D000818:Animals; D001921:Brain / Q000378:metabolism*; D004721:Endoplasmic Reticulum / Q000378:metabolism; D005455:Fluorescent Antibody Technique; D015870:Gene Expression; D006056:Golgi Apparatus / Q000378:metabolism; D008297:Male; D008565:Membrane Proteins / Q000032:analysis / Q000096:biosynthesis*; D008969:Molecular Sequence Data; D009132:Muscles / Q000166:cytology / Q000378:metabolism*; D009419:Nerve Tissue Proteins / Q000032:analysis / Q000096:biosynthesis*; D016133:Polymerase Chain Reaction / Q000379:methods; D050683:R-SNARE Proteins; D051381:Rats; D017208:Rats, Wistar; D017386:Sequence Homology, Amino Acid; D014158:Transcription, Genetic
D008565:Membrane Proteins; D009419:Nerve Tissue Proteins; D050683:R-SNARE Proteins