P2X(7) receptors are redistributed on human monocytes after pore formation in response to prolonged agonist exposure.
The P2X(7) cell surface receptor is responsible for adenosine triphosphate-dependent lysis of immune cells following the formation of non-selective membrane pores. This study examined changes in P2X(7) receptor distribution following agonist treatment. Human THP-1 monocytes were exposed to the agonist 2'-3'-O-(4-benzoyl-benzoyl) adenosine 5'-triphosphate for 1-40 min after which P2X(7) receptors were immunogold labelled. The number and distribution of P2X(7) receptors on the cell membrane were quantified using transmission electron microscopy. Increasing the time of agonist exposure resulted in clustering of P2X(7) receptors, a decrease in individual P2X(7) receptors and no change in the total number of P2X(7) receptors. These results suggest that pore formation does not involve further insertion or initial movement of receptors in the membrane but that P2X(7) receptors do cluster together after prolonged activation.
Connon
Che J
CJ
Department of Optometry and Vision Sciences, Cardiff University, Cardiff, UK. connoncj@cf.ac.uk
Young
Robert D
RD
Kidd
Emma J
EJ
D000255:Adenosine Triphosphate / Q000031:analogs & derivatives* / Q000494:pharmacology*; D002478:Cells, Cultured; D005110:Extracellular Space / Q000378:metabolism; D006801:Humans; D007150:Immunohistochemistry; D008854:Microscopy, Electron; D009000:Monocytes / Q000187:drug effects* / Q000378:metabolism; D058910:Purinergic P2 Receptor Agonists; D018048:Receptors, Purinergic P2 / Q000378:metabolism; D058486:Receptors, Purinergic P2X7; D015398:Signal Transduction; D013194:Staining and Labeling; D013997:Time Factors
C546468:P2RX7 protein, human; D058910:Purinergic P2 Receptor Agonists; D018048:Receptors, Purinergic P2; D058486:Receptors, Purinergic P2X7; C033901:3'-O-(4-benzoyl)benzoyladenosine 5'-triphosphate; D000255:Adenosine Triphosphate