Association of GABA(B) receptors and members of the 14-3-3 family of signaling proteins.
Two GABA(B) receptors, GABA(B)R1 and GABA(B)R2, have been cloned recently. Unlike other G protein-coupled receptors, the formation of a heterodimer between GABA(B)R1 and GABA(B)R2 is required for functional expression. We have used the yeast two hybrid system to identify proteins that interact with the C-terminus of GABA(B)R1. We report a direct association between GABA(B) receptors and two members of the 14-3-3 protein family, 14-3-3eta and 14-3-3zeta. We demonstrate that the C-terminus of GABA(B)R1 associates with 14-3-3zeta in rat brain preparations and tissue cultured cells, that they codistribute after rat brain fractionation, colocalize in neurons, and that the binding site overlaps partially with the coiled-coil domain of GABA(B)R1. Furthermore we show a reduced interaction between the C-terminal domains of GABA(B)R1 and GABA(B)R2 in the presence of 14-3-3. The results strongly suggest that GABA(B)R1 and 14-3-3 associate in the nervous system and begin to reveal the signaling complexities of the GABA(B)R1/GABA(B)R2 receptor heterodimer.
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A
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Medical Research Council Laboratory of Molecular Cell Biology and Department of Pharmacology, University College London, Gower Street, London, WC1E 6BT, United Kingdom.
Kittler
J T
JT
Uren
J M
JM
Calver
A R
AR
Pangalos
M N
MN
Walsh
F S
FS
Moss
S J
SJ
D048948:14-3-3 Proteins; D000818:Animals; D001923:Brain Chemistry / Q000502:physiology; D019556:COS Cells; D002458:Cell Fractionation; D015870:Gene Expression / Q000502:physiology; D006624:Hippocampus / Q000166:cytology; D066298:In Vitro Techniques; D009474:Neurons / Q000166:cytology / Q000378:metabolism; D017434:Protein Structure, Tertiary; D051381:Rats; D018080:Receptors, GABA-B / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D015398:Signal Transduction / Q000502:physiology*; D013569:Synapses / Q000378:metabolism; D014162:Transfection; D020798:Two-Hybrid System Techniques; D014446:Tyrosine 3-Monooxygenase / Q000235:genetics* / Q000378:metabolism*
D048948:14-3-3 Proteins; D018080:Receptors, GABA-B; D014446:Tyrosine 3-Monooxygenase