Targeting of neuromodulin (GAP-43) fusion proteins to growth cones in cultured rat embryonic neurons.
Neuromodulin (GAP-43) is a membrane protein that is transported to neuronal growth cones. Zuber and co-workers have proposed that the N-terminal 10 amino acid sequence of neuromodulin is sufficient to target proteins to growth cones. We demonstrate that a neuromodulin-beta-galactosidase fusion protein is transported to growth cones of cultured rat neurons, whereas a fusion protein containing the N-terminal 10 amino acids of neuromodulin and beta-galactosidase is not. A mutant neuromodulin lacking cysteines 3 and 4, the palmitylation sites required for membrane attachment, does not target beta-galactosidase to growth cones. We conclude that membrane attachment is required for growth cone accumulation and that structural elements, in addition to the first 10 amino acids of neuromodulin, may be required for growth cone targeting.
Liu
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Department of Pharmacology, University of Washington School of Medicine, Seattle 98195.
Chapman
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Storm
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D000818:Animals; D001483:Base Sequence; D015153:Blotting, Western; D002462:Cell Membrane / Q000378:metabolism; D002478:Cells, Cultured; D004622:Embryo, Mammalian / Q000294:innervation*; D005455:Fluorescent Antibody Technique; D019922:GAP-43 Protein; D008562:Membrane Glycoproteins / Q000235:genetics / Q000378:metabolism*; D008636:Mesencephalon / Q000166:cytology / Q000378:metabolism; D008969:Molecular Sequence Data; D009419:Nerve Tissue Proteins / Q000235:genetics / Q000378:metabolism*; D009474:Neurons / Q000166:cytology / Q000378:metabolism*; D009841:Oligonucleotides / Q000235:genetics; D051381:Rats; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D014162:Transfection; D001616:beta-Galactosidase / Q000235:genetics / Q000378:metabolism
D019922:GAP-43 Protein; D008562:Membrane Glycoproteins; D009419:Nerve Tissue Proteins; D009841:Oligonucleotides; D011993:Recombinant Fusion Proteins; D001616:beta-Galactosidase