Daniel T Baptista-Hon

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BACKGROUND AND PURPOSE Morphine is an antagonist at 5-HT(3) A receptors. 5-HT(3) and opioid receptors are expressed in many of the same neuronal pathways where they modulate gut motility, pain and reinforcement. There is increasing interest in the 5-HT3B subunit, which confers altered pharmacology to 5-HT(3) receptors. We investigated the mechanisms of(More)
The 5-HT3A receptor homology model, based on the partial structure of the nicotinic acetylcholine receptor from Torpedo marmorata, reveals an asymmetric ion channel with five portals framed by adjacent helical amphipathic (HA) stretches within the 114-residue loop between the M3 and M4 membrane-spanning domains. The positive charge of Arg-436, located(More)
Functional expression of voltage-gated Na(+) channels (VGSCs) has been demonstrated in multiple cancer cell types where channel activity induces invasive activity. The signaling mechanisms by which VGSCs promote oncogenesis remain poorly understood. We explored the signal transduction process critical to VGSC-mediated invasion on the basis of reports(More)
Picrotoxin and t-butylbicyclophosphorothionate (TBPS) are GABA(A) receptor (GABA(A)R) open channel blockers. However, picrotoxin displaceable [(35)S]TBPS binding to α1β2γ2 GABA(A)Rs occurs in the absence of GABA, suggesting that access to the binding site is independent of activation. Alternatively, spontaneous gating may provide access to the channel. In(More)
KEY POINTS The functional importance of residues in loop G of the GABAA receptor has not been investigated. D43 and T47 in the α1 subunit are of particular significance as their structural modification inhibits activation by GABA. While the T47C substitution had no significant effect, non-conservative substitution of either residue (D43C or T47R) reduced(More)
KEY POINTS The role of the β1 strand in GABAA receptor function is unclear. It lies anti-parallel to the β2 strand, which is known to participate in receptor activation. Molecular dynamics simulation revealed solvent accessible residues within the β1 strand of the GABAA β3 homopentamer that might be amenable to analysis using the substituted Cys(More)
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