Point mutation of glycine receptor alpha 1 subunit in the spasmodic mouse affects agonist responses.
Homozygotic spasmodic (spd/spd) mice suffer from a motor disorder resembling poisoning by the glycine receptor antagonist strychnine. Here, a point mutation was identified in the glycine receptor alpha 1 subunit gene of the spasmodic mouse which predicts an alanine-to-serine exchange at position 52 of the mature polypeptide. Upon expression in Xenopus laevis oocytes, alpha 1A52S receptor channels displayed reduced responses to glycine, beta-alanine and taurine when compared to recombinant alpha 1 glycine receptors. As glycine receptor content in spinal cord and native molecular weight appeared unaltered, this suggests that the spasmodic phenotype results from an altered neurotransmitter sensitivity of the mutant alpha 1A52S subunit.
Saul
B
B
Zentrum für Molekulare Biologie and Neurologische Universitätsklinik, Universität Heidelberg, Germany.
Schmieden
V
V
Kling
C
C
Mülhardt
C
C
Gass
P
P
Kuhse
J
J
Becker
C M
CM
D000409:Alanine / Q000494:pharmacology*; D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D017931:DNA Primers; D005998:Glycine / Q000494:pharmacology*; D051379:Mice; D008810:Mice, Inbred C57BL; D008817:Mice, Mutant Strains; D008969:Molecular Sequence Data; D017354:Point Mutation; D018009:Receptors, Glycine / Q000187:drug effects / Q000235:genetics*; D013035:Spasm / Q000235:genetics / Q000378:metabolism; D013654:Taurine / Q000494:pharmacology*; D014982:Xenopus laevis
D017931:DNA Primers; D018009:Receptors, Glycine; D013654:Taurine; D000409:Alanine; D005998:Glycine