Aplysia synapse associated protein (APSAP): Identification, characterization, and selective interactions with Shaker-type potassium channels

Kathryn J. Reissner, Heather D. Boyle, Xiaojing Ye, Thomas Carew

Research output: Contribution to journalArticle

Abstract

The vertebrate post-synaptic density (PSD) is a region of high molecular complexity in which dynamic protein interactions modulate receptor localization and synaptic function. Members of the membrane-associated guanylate kinase (MAGUK) family of proteins represent a major structural and functional component of the vertebrate PSD. In order to investigate the expression and significance of orthologous PSD components associated with the Aplysia sensory neuron-motor neuron synapse, we have cloned an Aplysia Dlg-MAGUK protein, which we identify as Aplysia synapse associated protein (ApSAP). As revealed by western blot, RT-PCR, and immunocytochemical analyses, ApSAP is predominantly expressed in the CNS and is located in both sensory neuron and motor neurons. The overall amino acid sequence of ApSAP is 55-61% identical to Drosophila Dlg and mammalian Dlg-MAGUK proteins, but is more highly conserved within L27, PDZ, SH3, and guanylate kinase domains. Because these conserved domains mediate salient interactions with receptors and other PSD components of the vertebrate synapse, we performed a series of GST pull-down assays using recombinant C-terminal tail proteins from various Aplysia receptors and channels containing C-terminal PDZ binding sequences. We have found that ApSAP selectively binds to an Aplysia Shaker-type channel AKv1.1, but not to (i) NMDA receptor subunit AcNR1-1, (ii) potassium channel AKv5.1, (iii) receptor tyrosine kinase ApTrkl, (iv) glutamate receptor ApGluR1/4, (v) glutamate receptor ApGluR2/3, or (vi) glutamate receptor ApGluR7. These findings provide preliminary information regarding the expression and interactions of Dlg-MAGUK proteins of the Aplysia CNS, and will inform questions aimed at a functional analysis of how interactions in a protein network such as the PSD may regulate synaptic strength.

Original languageEnglish (US)
Pages (from-to)1006-1018
Number of pages13
JournalJournal of Neurochemistry
Volume105
Issue number3
DOIs
StatePublished - May 2008

Fingerprint

Shaker Superfamily of Potassium Channels
Aplysia
Synapses
Guanylate Kinases
Post-Synaptic Density
Proteins
Neurons
Glutamate Receptors
Vertebrates
Motor Neurons
Sensory Receptor Cells
Functional analysis
Neurotransmitter Receptor
Potassium Channels
Receptor Protein-Tyrosine Kinases
N-Methyl-D-Aspartate Receptors
Drosophila

Keywords

  • Aplysia
  • Aplysia synapse associated protein
  • Membrane-associated guanylate kinase
  • Post-synaptic density
  • Potassium channel

ASJC Scopus subject areas

  • Biochemistry
  • Cellular and Molecular Neuroscience

Cite this

Aplysia synapse associated protein (APSAP) : Identification, characterization, and selective interactions with Shaker-type potassium channels. / Reissner, Kathryn J.; Boyle, Heather D.; Ye, Xiaojing; Carew, Thomas.

In: Journal of Neurochemistry, Vol. 105, No. 3, 05.2008, p. 1006-1018.

Research output: Contribution to journalArticle

@article{cf717358926f46e29e687ee4f0572e29,
title = "Aplysia synapse associated protein (APSAP): Identification, characterization, and selective interactions with Shaker-type potassium channels",
abstract = "The vertebrate post-synaptic density (PSD) is a region of high molecular complexity in which dynamic protein interactions modulate receptor localization and synaptic function. Members of the membrane-associated guanylate kinase (MAGUK) family of proteins represent a major structural and functional component of the vertebrate PSD. In order to investigate the expression and significance of orthologous PSD components associated with the Aplysia sensory neuron-motor neuron synapse, we have cloned an Aplysia Dlg-MAGUK protein, which we identify as Aplysia synapse associated protein (ApSAP). As revealed by western blot, RT-PCR, and immunocytochemical analyses, ApSAP is predominantly expressed in the CNS and is located in both sensory neuron and motor neurons. The overall amino acid sequence of ApSAP is 55-61{\%} identical to Drosophila Dlg and mammalian Dlg-MAGUK proteins, but is more highly conserved within L27, PDZ, SH3, and guanylate kinase domains. Because these conserved domains mediate salient interactions with receptors and other PSD components of the vertebrate synapse, we performed a series of GST pull-down assays using recombinant C-terminal tail proteins from various Aplysia receptors and channels containing C-terminal PDZ binding sequences. We have found that ApSAP selectively binds to an Aplysia Shaker-type channel AKv1.1, but not to (i) NMDA receptor subunit AcNR1-1, (ii) potassium channel AKv5.1, (iii) receptor tyrosine kinase ApTrkl, (iv) glutamate receptor ApGluR1/4, (v) glutamate receptor ApGluR2/3, or (vi) glutamate receptor ApGluR7. These findings provide preliminary information regarding the expression and interactions of Dlg-MAGUK proteins of the Aplysia CNS, and will inform questions aimed at a functional analysis of how interactions in a protein network such as the PSD may regulate synaptic strength.",
keywords = "Aplysia, Aplysia synapse associated protein, Membrane-associated guanylate kinase, Post-synaptic density, Potassium channel",
author = "Reissner, {Kathryn J.} and Boyle, {Heather D.} and Xiaojing Ye and Thomas Carew",
year = "2008",
month = "5",
doi = "10.1111/j.1471-4159.2007.05202.x",
language = "English (US)",
volume = "105",
pages = "1006--1018",
journal = "Journal of Neurochemistry",
issn = "0022-3042",
publisher = "Wiley-Blackwell",
number = "3",

}

TY - JOUR

T1 - Aplysia synapse associated protein (APSAP)

T2 - Identification, characterization, and selective interactions with Shaker-type potassium channels

AU - Reissner, Kathryn J.

AU - Boyle, Heather D.

AU - Ye, Xiaojing

AU - Carew, Thomas

PY - 2008/5

Y1 - 2008/5

N2 - The vertebrate post-synaptic density (PSD) is a region of high molecular complexity in which dynamic protein interactions modulate receptor localization and synaptic function. Members of the membrane-associated guanylate kinase (MAGUK) family of proteins represent a major structural and functional component of the vertebrate PSD. In order to investigate the expression and significance of orthologous PSD components associated with the Aplysia sensory neuron-motor neuron synapse, we have cloned an Aplysia Dlg-MAGUK protein, which we identify as Aplysia synapse associated protein (ApSAP). As revealed by western blot, RT-PCR, and immunocytochemical analyses, ApSAP is predominantly expressed in the CNS and is located in both sensory neuron and motor neurons. The overall amino acid sequence of ApSAP is 55-61% identical to Drosophila Dlg and mammalian Dlg-MAGUK proteins, but is more highly conserved within L27, PDZ, SH3, and guanylate kinase domains. Because these conserved domains mediate salient interactions with receptors and other PSD components of the vertebrate synapse, we performed a series of GST pull-down assays using recombinant C-terminal tail proteins from various Aplysia receptors and channels containing C-terminal PDZ binding sequences. We have found that ApSAP selectively binds to an Aplysia Shaker-type channel AKv1.1, but not to (i) NMDA receptor subunit AcNR1-1, (ii) potassium channel AKv5.1, (iii) receptor tyrosine kinase ApTrkl, (iv) glutamate receptor ApGluR1/4, (v) glutamate receptor ApGluR2/3, or (vi) glutamate receptor ApGluR7. These findings provide preliminary information regarding the expression and interactions of Dlg-MAGUK proteins of the Aplysia CNS, and will inform questions aimed at a functional analysis of how interactions in a protein network such as the PSD may regulate synaptic strength.

AB - The vertebrate post-synaptic density (PSD) is a region of high molecular complexity in which dynamic protein interactions modulate receptor localization and synaptic function. Members of the membrane-associated guanylate kinase (MAGUK) family of proteins represent a major structural and functional component of the vertebrate PSD. In order to investigate the expression and significance of orthologous PSD components associated with the Aplysia sensory neuron-motor neuron synapse, we have cloned an Aplysia Dlg-MAGUK protein, which we identify as Aplysia synapse associated protein (ApSAP). As revealed by western blot, RT-PCR, and immunocytochemical analyses, ApSAP is predominantly expressed in the CNS and is located in both sensory neuron and motor neurons. The overall amino acid sequence of ApSAP is 55-61% identical to Drosophila Dlg and mammalian Dlg-MAGUK proteins, but is more highly conserved within L27, PDZ, SH3, and guanylate kinase domains. Because these conserved domains mediate salient interactions with receptors and other PSD components of the vertebrate synapse, we performed a series of GST pull-down assays using recombinant C-terminal tail proteins from various Aplysia receptors and channels containing C-terminal PDZ binding sequences. We have found that ApSAP selectively binds to an Aplysia Shaker-type channel AKv1.1, but not to (i) NMDA receptor subunit AcNR1-1, (ii) potassium channel AKv5.1, (iii) receptor tyrosine kinase ApTrkl, (iv) glutamate receptor ApGluR1/4, (v) glutamate receptor ApGluR2/3, or (vi) glutamate receptor ApGluR7. These findings provide preliminary information regarding the expression and interactions of Dlg-MAGUK proteins of the Aplysia CNS, and will inform questions aimed at a functional analysis of how interactions in a protein network such as the PSD may regulate synaptic strength.

KW - Aplysia

KW - Aplysia synapse associated protein

KW - Membrane-associated guanylate kinase

KW - Post-synaptic density

KW - Potassium channel

UR - http://www.scopus.com/inward/record.url?scp=42449094676&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=42449094676&partnerID=8YFLogxK

U2 - 10.1111/j.1471-4159.2007.05202.x

DO - 10.1111/j.1471-4159.2007.05202.x

M3 - Article

C2 - 18182049

AN - SCOPUS:42449094676

VL - 105

SP - 1006

EP - 1018

JO - Journal of Neurochemistry

JF - Journal of Neurochemistry

SN - 0022-3042

IS - 3

ER -