title: Molecular analysis of the function of the neuronal growth-associated protein GAP-43 by genetic intervention.
abstract: GAP-43 is a presynaptic membrane phosphoprotein that has been implicated in both the development and the modulation of neural connections. The availability of cDNA clones for GAP-43 makes it possible to examine with greater precision its role in neuronal outgrowth and physiology. We used Northern blots and in situ hybridization with GAP-43 antisense RNA probes to show that GAP-43 is expressed selectively in associative regions of the adult brain. Immunocytochemical analyses showed alterations in the pattern of GAP-43 expression in the hippocampus during reactive synaptogenesis following lesions of the perforant pathway. Genetic intervention methodology was used to analyze the molecular nature of GAP-43 involvement in synaptic plasticity. GAP-43-transfected PC12 cells displayed an enhanced response to nerve growth factor, suggesting that GAP-43 may be directly involved in neurite extension and in the modulation of the neuronal response to extrinsic trophic factors. Studies of PC12 cell transfectants, in which the synthesis of GAP-43 was blocked by expression of GAP-43 antisense RNA, showed that evoked dopamine release was significantly attenuated in these cells. The use of gene transfer into neurons with the HSV-1 vector is presented as a method of analyzing the interaction of GAP-43 with signal transduction systems during neurotransmitter release.
authors.affiliation: Department of Psychobiology, University of California, Irvine 92717.
authors.forename: R L
authors.initials: RL
authors.lastname: Neve
authors.forename: K J
authors.initials: KJ
authors.lastname: Ivins
authors.forename: L I
authors.initials: LI
authors.lastname: Benowitz
authors.forename: M J
authors.initials: MJ
authors.lastname: During
authors.forename: A I
authors.initials: AI
authors.lastname: Geller
mesh_terms: D000818:Animals; D001923:Brain Chemistry; D004247:DNA / Q000235:genetics; D016373:DNA, Antisense / Q000235:genetics; D019922:GAP-43 Protein; D005786:Gene Expression Regulation / Q000187:drug effects; D005822:Genetic Vectors; D006801:Humans; D008562:Membrane Glycoproteins / Q000096:biosynthesis / Q000235:genetics / Q000502:physiology*; D009414:Nerve Growth Factors / Q000494:pharmacology; D009419:Nerve Tissue Proteins / Q000096:biosynthesis / Q000235:genetics / Q000502:physiology*; D009473:Neuronal Plasticity / Q000502:physiology*; D016716:PC12 Cells / Q000187:drug effects / Q000378:metabolism; D010766:Phosphorylation; D011499:Protein Processing, Post-Translational; D016372:RNA, Antisense / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism; D011993:Recombinant Fusion Proteins / Q000096:biosynthesis / Q000235:genetics; D015398:Signal Transduction; D018139:Simplexvirus / Q000235:genetics; D014162:Transfection
chemical_list: D016373:DNA, Antisense; D019922:GAP-43 Protein; D008562:Membrane Glycoproteins; D009414:Nerve Growth Factors; D009419:Nerve Tissue Proteins; D016372:RNA, Antisense; D012333:RNA, Messenger; D011993:Recombinant Fusion Proteins; D004247:DNA