Endogenous transport systems in the Xenopus laevis oocyte plasma membrane.
Oocytes of the South African clawed frog Xenopus laevis are widely used as a heterologous expression system for the characterization of transport systems such as passive and active membrane transporters, receptors and a whole plethora of other membrane proteins originally derived from animal or plant tissues. The large size of the oocytes and the high degree of expression of exogenous mRNA or cDNA makes them an optimal tool, when compared with other expression systems such as yeast, Escherichia coli or eukaryotic cell lines, for the expression and functional characterization of membrane proteins. This easy to handle expression system is becoming increasingly attractive for pharmacological research. Commercially available automated systems that microinject mRNA into the oocytes and perform electrophysiological measurements fully automatically allow for a mass screening of new computer designed drugs to target membrane transport proteins. Yet, the oocytes possess a large variety of endogenous membrane transporters and it is absolutely mandatory to distinguish the endogenous transporters from the heterologous, expressed transport systems. Here, we review briefly the endogenous membrane transport systems of the oocytes.
Sobczak
Katja
K
Institute of Animal Physiology, Westfalian Wilhelms-University, Hindenburgplatz 55, Muenster, Germany.
Bangel-Ruland
Nadine
N
Leier
Geraldine
G
Weber
Wolf-Michael
WM
D000818:Animals; D015220:Calcium Channels / Q000737:chemistry; D002462:Cell Membrane / Q000378:metabolism*; D018076:DNA, Complementary / Q000378:metabolism; D004058:Diffusion; D004594:Electrophysiology / Q000379:methods; D007473:Ion Channels / Q000378:metabolism; D007477:Ions; D009865:Oocytes / Q000378:metabolism*; D015221:Potassium Channels / Q000737:chemistry; D012333:RNA, Messenger / Q000378:metabolism; D015222:Sodium Channels / Q000737:chemistry; D014867:Water / Q000737:chemistry; D014982:Xenopus laevis / Q000378:metabolism*
D015220:Calcium Channels; D018076:DNA, Complementary; D007473:Ion Channels; D007477:Ions; D015221:Potassium Channels; D012333:RNA, Messenger; D015222:Sodium Channels; D014867:Water