Igloo, a GAP-43-related gene expressed in the developing nervous system of Drosophila.
GAP-43 (growth-associated protein, 43 x 10(3) M(r)) is an essential, membrane-associated, neuronal phosphoprotein in vertebrates. The protein is abundantly produced in the growth cones of developing and regenerating neurons, and it is phosphorylated upon induction of long-term potentiation (LTP). Prior work has identified GAP-43-like proteins only in chordates. In this paper, a nervous system-specific gene from Drosophila melanogaster is described that encodes two proteins sharing biochemical activities and sequence homology with GAP-43. The region of homology encompasses the calmodulin-binding domain and protein kinase C (PKC) phosphorylation site of GAP-43. The fly proteins are shown to bind Drosophila calmodulin (CaM), and are phosphorylated by purified PKC after a fashion predicted from prior work with vertebrate GAP-43. GAP-43 is modified by palmitoylation. An amino-terminal myristoylation site is described for the Drosophila protein, which may play a similar role in membrane association in the fly. While a small family of GAP-43-related genes has been recognized in vertebrates, only a single gene appears to be present in the fly. As the Drosophila gene encodes two proteins, each with multiple calmodulin-binding domains and repeated sites for PKC phosphorylation, it may afford functions provided by the family of vertebrate genes.
Neel
V A
VA
Laboratory of Genetics, Rockefeller University, New York, NY 10021.
Young
M W
MW
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D015152:Blotting, Northern; D002147:Calmodulin / Q000378:metabolism; D003001:Cloning, Molecular; D017931:DNA Primers / Q000235:genetics; D004331:Drosophila melanogaster / Q000196:embryology* / Q000235:genetics; D019922:GAP-43 Protein; D015870:Gene Expression / Q000502:physiology; D006054:Goldfish / Q000235:genetics; D006133:Growth Substances / Q000235:genetics*; D008562:Membrane Glycoproteins / Q000235:genetics* / Q000378:metabolism; D008969:Molecular Sequence Data; D009419:Nerve Tissue Proteins / Q000235:genetics* / Q000378:metabolism; D009420:Nervous System / Q000196:embryology*; D051381:Rats; D016415:Sequence Alignment
D002147:Calmodulin; D017931:DNA Primers; D019922:GAP-43 Protein; D006133:Growth Substances; D008562:Membrane Glycoproteins; D009419:Nerve Tissue Proteins