110 Functional characterization of calcium channel reconstituted on xenopus oocytes with neuronal α1 and β subunits

Development of reliable expression systems for use in identification and functional characterization of proteins required for secretory Cl channel activity is key to understanding the molecular basis of cystic fibrosis (CF). Until now, heterologous expression of epithelial Cl channels had not been accomplished. We show here that Xenopus oocytes express an adenosine 3',5'-cyclic monophosphate (cAMP)-activated Cl conductance after injection of mRNA from shark rectal gland. Current through this conductance was rapidly activated by intracellular application of cAMP, reversed near the chloride equilibrium potential (ECl), blocked by the Cl channel inhibitor 5-nitro-2-(3-phenylpropylamino) benzoate, and was not affected by preincubation with the intracellular calcium buffer bis-(2-amino-5-methylphenoxy)-ethane-N,N,N',N'-tetraacetic acid tetraacetoxymethyl ester, a condition that prohibits activation of the endogenous Ca-activated Cl conductance.

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Functional Characterization of the Arabidopsis Abscisic Acid Transporters NPF4.5 and NPF4.6 in Xenopus Oocytes

Frontiers in Plant Science ◽

10.3389/fpls.2020.00144 ◽

2020 ◽

Vol 11 ◽

Cited By ~ 3

Author(s):

Sophie Léran ◽

Mélanie Noguero ◽

Claire Corratgé-Faillie ◽

Yann Boursiac ◽

Chantal Brachet ◽

...

Keyword(s):

Abscisic Acid ◽

Xenopus Oocytes ◽

Functional Characterization

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Expression and functional characterization of the cardiac L-type calcium channel carrying a skeletal muscle DHP-receptor mutation causing hypokalaemic periodic paralysis

Pflügers Archiv - European Journal of Physiology ◽

10.1007/s004240050021 ◽

1996 ◽

Vol 431 (3) ◽

pp. 461 ◽

Cited By ~ 30

Author(s):

H. Lerche ◽

N. Klugbauer ◽

F. Lehmann-Horn ◽

F. Hofmann ◽

W. Melzer

Keyword(s):

Skeletal Muscle ◽

Calcium Channel ◽

Functional Characterization ◽

Periodic Paralysis ◽

Hypokalaemic Periodic Paralysis

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Structure and Functional Characterization of a Novel Human Low-Voltage Activated Calcium Channel

Journal of Neurochemistry ◽

10.1046/j.1471-4159.1999.0720791.x ◽

1999 ◽

Vol 72 (2) ◽

pp. 791-799 ◽

Cited By ~ 70

Author(s):

Mark E. Williams ◽

Mark S. Washburn ◽

Michael Hans ◽

Arturo Urrutia ◽

Paul F. Brust ◽

...

Keyword(s):

Calcium Channel ◽

Low Voltage ◽

Functional Characterization

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Revisiting the functional properties of NPF6.3/NRT1.1/CHL1 in xenopus oocytes

10.1101/244467 ◽

2018 ◽

Cited By ~ 2

Author(s):

Mélanie Noguero ◽

Sophie Léran ◽

Eléonore Bouguyon ◽

Chantal Brachet ◽

Pascal Tillard ◽

...

Keyword(s):

Transport Properties ◽

Xenopus Oocytes ◽

Nitrate Concentration ◽

Functional Characterization ◽

Nitrate Transport ◽

Experimental Conditions ◽

Point Mutant ◽

Electrode Voltage ◽

Nitrate Transporters

ABSTRACTWithin the Arabidopsis NPF proteins, most of the characterized nitrate transporters are low-affinity transporters, whereas the functional characterization of NPF6.3/NRT1.1 has revealed interesting transport properties: the transport of nitrate and auxin, the eletrogenicity of the nitrate transport and a dual-affinity transport behavior for nitrate depending on external nitrate concentration. However, some of these properties remained controversial and were challenged here. We functionally express WT NPF6.3/NRT1.1 and some of its mutant in Xenopus oocytes and used a combination of uptake experiments using 15N-labelled nitrate and two-electrode voltage-clamp. In our experimental conditions in xenopus oocytes, in the presence or in the absence of external chloride, NPF6.3/NRT1.1 behaves as a non-electrogenic and pure low-affinity transporter. Moreover, further functional characterization of a NPF6.3/NRT1.1 point mutant, P492L, allowed us to hypothesize that NPF6.3/NRT1.1 is regulated by internal nitrate concentration and that the internal perception site involves the P492 residue.

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