Click here to close Hello! We notice that you are using Internet Explorer, which is not supported by Xenbase and may cause the site to display incorrectly. We suggest using a current version of Chrome, FireFox, or Safari.
XB-ART-20418
Proc Natl Acad Sci U S A 1994 Dec 20;9126:12725-9.
Show Gene links Show Anatomy links

Cationic modulation of rho 1-type gamma-aminobutyrate receptors expressed in Xenopus oocytes.

Calvo DJ , Vazquez AE , Miledi R .


???displayArticle.abstract???
A study was made of the effects of di- and trivalent cations on homomeric rho 1-type gamma-aminobutyrate (GABA rho 1) receptors expressed in Xenopus oocytes after injection of mRNA coding for the GABA rho 1 subunit. GABA elicited large currents with a Kd approximately 1 microM. The properties of these GABA rho 1 receptors were similar to those of native bicuculline-resistant GABA receptors expressed by retinal mRNA. GABA rho 1 currents showed very little desensitization, were blocked by picrotoxin but not by bicuculline, and were not modulated by barbiturates, benzodiazepines, or beta-carbolines. Zn2+ reversibly decreased GABA rho 1 responses (IC50 = 22 microM). Other divalent cations were also tested and their rank order of potency was: Zn2+ approximately Ni2+ approximately Cu2+ > Cd2+, whereas Ba2+, Co2+, Sr2+, Mn2+, Mg2+, and Ca2+ showed little or no effect. In contrast, La3+ reversibly potentiated the GABA currents mediated by homomeric GABA rho 1 receptors, with an EC50 = 135 microM and a maximal potentiation of about 100% (GABA, 1 microM; La3+, 1 mM). Other lanthanides showed similar effects (Lu3+ > Eu3+ > Tb3+ > Gd3+ > Er3% > Nd3+ > La3+ > Ce3+). Thus, GABA rho 1 receptors contain sites for cationic recognition, and in particular, Zn2+ may play a role during synaptic transmission in the retina.

???displayArticle.pubmedLink??? 7809110
???displayArticle.pmcLink??? PMC45512
???displayArticle.link??? Proc Natl Acad Sci U S A
???displayArticle.grants??? [+]

Species referenced: Xenopus laevis
Genes referenced: rho rho.2

References [+] :
Assaf, Release of endogenous Zn2+ from brain tissue during activity. , Pubmed