Structure and function of purinergic P2X receptors

Purinergic P2X receptors are cationic channels in the cell membrane which are opened by extracellular ATP. They are widely expressed in different tissues like skeletal muscle, endothelial cells, neurons and leukocytes. ATP is released from nerve endings into the extracellular space as a neurotransmitter and from several other cells during pathophysiological conditions like hypoxia, thrombosis and inflammation. We investigate the function of P2X receptors in lymphocytes and macrophages by means of the whole-cell and single-channel voltage clamp technique and by measurement of P2X-dependent changes in the membrane potential and the intracellular Ca2+ and Na+-concentration in single cells by voltage clamp fluorimetry and in cell populations using flow cytometry (FACS). In collaboration with molecular biologists (Prof. Günther Schmalzing, RWTH Aachen) mutated P2X receptor constructs are expressed in Xenopus oocytes and mammalian cells. Structure-function relationships of the receptors and the interaction of P2X receptors with other ion channels (pannexin, anion channels,trp channels) are investigated by the measurement of whole cell and single channel P2X-dependent ionic currents and fluorescence measurements.

Supported by the DFG and the Roux programme of the Medical Faculty of the Martin Luther University.

Mechanism of sphingosine phosphate-induced ATP secretion

Macrophyges are versatile players coordinating inflammatory and regenerative processes under pathological conditions in which sphingosine-1-phosphate (S1P)-mediated migration is essential. We investigated the involved signaling cascade by means of voltage clamp, measurement of ATP secretion, and wound healing assay. Malte Berthold (Ph.D. student)

Amelie Spilker

Doctoral candidates:

Mira Trang
Eike Schön
Danyal Zahiri
Markus Schneider
Hannah Dentler
Ida Schiller
Thomas Kendzierski

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