ApTrkl, a Trk-like receptor, mediates serotonin- dependent ERK activation and long-term facilitation in Aplysia sensory neurons.
The Trk family of receptor tyrosine kinases plays a role in synaptic plasticity and in behavioral memory in mammals. Here, we report the discovery of a Trk-like receptor, ApTrkl, in Aplysia. We show that it is expressed in the sensory neurons, the locus for synaptic facilitation, which is a cellular model for memory formation. Serotonin, the facilitatory neurotransmitter, activates ApTrkl, which, in turn, leads to activation of ERK. Finally, inhibiting the activation of ApTrkl with the Trk inhibitor K252a or using dsRNA to inhibit ApTrkl blocks the serotonin-mediated activation of ERK in the cell body, as well as the cell-wide long-term facilitation induced by 5-HT application to the cell body. Thus, transactivation of the receptor tyrosine kinase ApTrkl by serotonin is an essential step in the biochemical events leading to long-term facilitation in Aplysia.
Ormond
Jake
J
Montreal Neurological Institute, McGill University, 3801 University Avenue, Montreal, Quebec H3A-2B4, Canada.
Hislop
Jonathan
J
Zhao
Yali
Y
Webb
Neil
N
Vaillaincourt
Francois
F
Dyer
John R
JR
Ferraro
Gino
G
Barker
Phil
P
Martin
Kelsey C
KC
Sossin
Wayne S
WS
D000595:Amino Acid Sequence; D000818:Animals; D001048:Aplysia / Q000502:physiology*; D001483:Base Sequence; D015153:Blotting, Western; D004789:Enzyme Activation / Q000502:physiology; D004791:Enzyme Inhibitors / Q000494:pharmacology; D019706:Excitatory Postsynaptic Potentials; D048049:Extracellular Signal-Regulated MAP Kinases / Q000187:drug effects / Q000502:physiology*; D006801:Humans; D007150:Immunohistochemistry; D017774:Long-Term Potentiation / Q000502:physiology; D008969:Molecular Sequence Data; D009473:Neuronal Plasticity / Q000502:physiology; D009475:Neurons, Afferent / Q000502:physiology*; D020794:Receptor Protein-Tyrosine Kinases / Q000502:physiology*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012701:Serotonin / Q000378:metabolism
D004791:Enzyme Inhibitors; D012701:Serotonin; D020794:Receptor Protein-Tyrosine Kinases; D048049:Extracellular Signal-Regulated MAP Kinases