Identification of a nonneuronal isoform of synaptotagmin.
Synaptotagmins, which have been found exclusively in neuroendocrine or exocrine tissues, have been implicated in the regulation of secretory vesicle fusion with the plasma membrane. The present paper describes a synaptotagmin isoform (synaptotagmin-5) which exhibits 49% amino acid identity to synaptotagmin-1 and -2. Synaptotagmin-5 mRNA is expressed in rat kidney, adipose tissue, lung, and heart, as well as at higher levels in brain and PC12 cells. Antiserum specific for the synaptotagmin-5 isoform recognizes a protein of about 50 kDa which is about 6-fold more abundant in brain synaptic vesicles than in whole brain membranes.
Hudson
A W
AW
Department of Cell Biology, Harvard Medical School, Boston, MA 02115, USA.
Birnbaum
M J
MJ
D000273:Adipose Tissue / Q000378:metabolism; D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D001921:Brain / Q000378:metabolism*; D002135:Calcium-Binding Proteins; D002460:Cell Line; D003001:Cloning, Molecular; D006224:Cricetinae; D015870:Gene Expression; D007668:Kidney / Q000378:metabolism; D008168:Lung / Q000378:metabolism; D008562:Membrane Glycoproteins / Q000096:biosynthesis* / Q000737:chemistry / Q000302:isolation & purification; D008969:Molecular Sequence Data; D008970:Molecular Weight; D018482:Muscle, Skeletal / Q000378:metabolism; D009206:Myocardium / Q000378:metabolism; D009419:Nerve Tissue Proteins / Q000096:biosynthesis* / Q000737:chemistry / Q000302:isolation & purification; D009928:Organ Specificity; D016716:PC12 Cells; D010802:Phylogeny; D012333:RNA, Messenger / Q000032:analysis / Q000096:biosynthesis; D051381:Rats; D011994:Recombinant Proteins / Q000096:biosynthesis / Q000737:chemistry; D017386:Sequence Homology, Amino Acid; D013572:Synaptic Vesicles / Q000378:metabolism*; D050863:Synaptotagmin I; D050857:Synaptotagmins; D014162:Transfection
D002135:Calcium-Binding Proteins; D008562:Membrane Glycoproteins; D009419:Nerve Tissue Proteins; D012333:RNA, Messenger; D011994:Recombinant Proteins; D050863:Synaptotagmin I; C494312:Syt1 protein, rat; C494297:Syt5 protein, rat; D050857:Synaptotagmins