Human 5-HT3A -- Ser 397

Species Original Mutated to Mutation
Human Ser 397  


Rat Equivalent Thr 396    
Mouse Equivalent Thr 402 Ala T402A


The mutation was made in the mouse 5-HT3A long splice variant in which Thr402 (mouse 5-HT3A short) is numbered Thr408 (due to the insertion of an extra 6 amino acids).

Simultaneous mutation of this residue and all other putative phosphorylation sites (replacement by alanine) in the mouse (cloned from NCB-20 cells) 5-HT3A receptor's intracellular loops (TM1-2 and TM3-4) failed to affect modulation by ethanol. Recombinant 5-HT3A receptors were expressed in Xenopus Oocytes (cRNA injection) and 5-HT-evoked currents were recorded using two-electrode voltage-clamp. The effect of replacing all intracellular Ser, Thr and Tyr (by Ala) was to shift the 5-HT concentration-response relationship slightly to the left (more potent).

Machu TK, Coultrap SJ, Waugh MD, Hamilton ME. (1999) Mutation of putative phosphorylation sites in the 5-hydroxytryptamine3 receptor does not eliminate its modulation by ethanol. Alcohol Clin Exp Res. 23(1):12-7

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