The Journal of Neuroscience, April 1, 2003, 23(7):2675
Identification and Characterization of Aplysia
Adducin, an Aplysia Cytoskeletal Protein Homologous to
Mammalian Adducins: Increased Phosphorylation at a Protein Kinase C
Consensus Site during Long-Term Synaptic Facilitation
Lore M.
Gruenbaum1,
Diana M.
Gilligan2,
Marina
R.
Picciotto3,
Stéphane
Marinesco4, and
Thomas J.
Carew4
1 Boehringer Ingelheim Pharmaceuticals, Ridgefield,
Connecticut 06877, 2 Puget Sound Blood Center, Seattle,
Washington 98104, 3 Department of Psychiatry, Yale
University School of Medicine, New Haven, Connecticut 06508, and
4 Department of Neurobiology and Behavior, Center for
Learning and Memory, University of California, Irvine, California
92697-4550
Structural changes at synapses are associated with
long-term facilitation (LTF) of synaptic transmission between sensory
and motor neurons in Aplysia. We have cloned a cDNA
encoding Aplysia adducin (ApADD), the
Aplysia homolog of mammalian adducins that are
regulatory components of the membrane cytoskeleton. ApADD is recovered
in the particulate fraction of nervous system extracts and is localized
predominantly in the submembraneous region of Aplysia
neurons. ApADD is phosphorylated in vitro by protein
kinase C (PKC) at a site homologous to the in vivo PKC
phosphorylation site in mammalian adducins. Phosphorylation of ApADD at
this site is also detected in vivo in the intact
Aplysia nervous system and is increased 18 hr after
serotonin-induced LTF. In contrast, there is no change in
phosphorylation during short-term facilitation or 1 hr after initial
LTF induction. Thus, ApADD is modulated specifically with later phases
of LTF and provides an attractive candidate protein that contributes to
structural changes accompanying long-lasting synaptic alteration.
Key words:
adducins; protein kinase C; long-term facilitation; cytoskeleton; synaptic plasticity; serotonin
Copyright © 2003 Society for Neuroscience 0270-6474/03/2372675-11$05.00/0