title: A third member of the synapsin gene family.
abstract: Synapsins are a family of neuron-specific synaptic vesicle-associated phosphoproteins that have been implicated in synaptogenesis and in the modulation of neurotransmitter release. In mammals, distinct genes for synapsins I and II have been identified, each of which gives rise to two alternatively spliced isoforms. We have now cloned and characterized a third member of the synapsin gene family, synapsin III, from human DNA. Synapsin III gives rise to at least one protein isoform, designated synapsin IIIa, in several mammalian species. Synapsin IIIa is associated with synaptic vesicles, and its expression appears to be neuron-specific. The primary structure of synapsin IIIa conforms to the domain model previously described for the synapsin family, with domains A, C, and E exhibiting the highest degree of conservation. Synapsin IIIa contains a novel domain, termed domain J, located between domains C and E. The similarities among synapsins I, II, and III in domain organization, neuron-specific expression, and subcellular localization suggest a possible role for synapsin III in the regulation of neurotransmitter release and synaptogenesis. The human synapsin III gene is located on chromosome 22q12-13, which has been identified as a possible schizophrenia susceptibility locus. On the basis of this localization and the well established neurobiological roles of the synapsins, synapsin III represents a candidate gene for schizophrenia.
authors.affiliation: Laboratory of Molecular and Cellular Neuroscience, The Rockefeller University, 1230 York Avenue, New York, NY 10021-6399, USA. koah@rockvax.rockefeller.edu
authors.forename: H T
authors.initials: HT
authors.lastname: Kao
authors.forename: B
authors.initials: B
authors.lastname: Porton
authors.forename: A J
authors.initials: AJ
authors.lastname: Czernik
authors.forename: J
authors.initials: J
authors.lastname: Feng
authors.forename: G
authors.initials: G
authors.lastname: Yiu
authors.forename: M
authors.initials: M
authors.lastname: Häring
authors.forename: F
authors.initials: F
authors.lastname: Benfenati
authors.forename: P
authors.initials: P
authors.lastname: Greengard
mesh_terms: D017398:Alternative Splicing; D000595:Amino Acid Sequence; D000818:Animals; D001921:Brain / Q000378:metabolism*; D002540:Cerebral Cortex / Q000378:metabolism; D002874:Chromosome Mapping; D002892:Chromosomes, Human, Pair 22; D019976:Cloning, Organism; D018076:DNA, Complementary; D005091:Exons; D017353:Gene Deletion; D006801:Humans; D007438:Introns; D051379:Mice; D018345:Mice, Knockout; D008969:Molecular Sequence Data; D005810:Multigene Family; D009479:Neuropeptides / Q000096:biosynthesis* / Q000737:chemistry / Q000235:genetics*; D009928:Organ Specificity; D010750:Phosphoproteins / Q000096:biosynthesis* / Q000737:chemistry / Q000235:genetics*; D016133:Polymerase Chain Reaction; D012333:RNA, Messenger / Q000096:biosynthesis; D051381:Rats; D011994:Recombinant Proteins / Q000096:biosynthesis / Q000737:chemistry; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D016704:Synapsins / Q000096:biosynthesis* / Q000737:chemistry / Q000172:deficiency / Q000235:genetics*; D013572:Synaptic Vesicles / Q000378:metabolism; D014158:Transcription, Genetic
chemical_list: D018076:DNA, Complementary; D009479:Neuropeptides; D010750:Phosphoproteins; D012333:RNA, Messenger; D011994:Recombinant Proteins; C111812:SYN3 protein, human; D016704:Synapsins