Human 5-HT3A -- Tyr 83

Species Original Mutated to Mutation
Human Tyr 83  

 

Rat Equivalent Tyr 88    
Mouse Equivalent Tyr 88

Ala

Ser

Y88A

Y88S

 

mTyr88Ala

Nine residues (Thr 86, Thr 87, Tyr 88, Ile 89, Tyr 91, Arg 92, Gln 93, Tyr 94, Trp 95) were mutated individually to alanine (alanine scanning mutagenesis). The ligands [3H]granisetron, curare, and serotonin were used to examine receptor binding.

W90F was analyzed instead of W90A, and it proved to be the only one that significantly affected the interaction of curare with the receptor. R92A was the only substitution that altered the affinity of the agonist serotonin. W90F, R92A, and Y94A all reduced the affinity of [3H] ganisetron. The periodicity of this effect suggests the involvement of a beta-strand.

Yan D, Schulte MK, Bloom KE, White MM (1999) Structural Features of the Ligand-binding Domain of the Serotonin 5HT3 Receptor. The Journal of Biological Chemistry 274 (9): 5537-5541

Eleven residues (Tyr 50, Tyr 73, Tyr 88, Tyr 91, Tyr 94, Tyr 141, Tyr 143, Tyr 153, Tyr 167, Tyr 234, Tyr 240) were mutated individually for alanine, serine and some residues for phenylalanine. The ligands [3H]granisetron and 5-HT were used to examine the prosperities of ligands binding sites and functional structure of the 5-HT3A receptor.

The mouse 5-HT3A receptors were expressed in Xenopus Oocytes using (cRNA injection) using two-electrode voltage-clamp technique and HEK293 cells were used in radioligand binding and calcium imaging assays to study an affinity and potency of the 5-HT3A receptor.

Mutants Y88A and Y88S are not crucial for structure and ligand binding of the mouse 5-HT3A receptors. Although [3H]granisetron binding was observed with Y88A and Y88S mutants, these mutants are not significantly altered the affinity of the antagonist [3H] granisetron from wild-type receptor.

Price KL, Lummis SCR (2004). The role of Tyrosine residues in the extracellular domain of the 5-Hydroxytryptamine3 receptor.The Journal of Biological Chemistry 279(22):23294-23301

 

mTyr88Ser

Mutants Y88A and Y88S are not crucial for structure and ligand binding of the mouse 5-HT3A receptors. Although [3H]granisetron binding was observed with Y88A and Y88S mutants, these mutants are not significantly altered the affinity of the antagonist [3H] granisetron from wild-type receptor.

Price KL, Lummis SCR (2004). The role of Tyrosine residues in the extracellular domain of the 5-Hydroxytryptamine3 receptor.The Journal of Biological Chemistry 279(22):23294-23301

 

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