The P2X7/P2X4 interaction shapes the purinergic response in murine macrophages
Gabriela Pérez-Flores1, Sébastien A Lévesque2, Jonathan Pacheco3
1School of Medicine, Universidad Autónoma de San Luis Potosí, San Luis Potosí, Mexico.
Abstract:
The ATP-gated P2X4 and P2X7 receptors are cation channels, co-expressed in excitable and non-excitable cells and play important roles in pain, bone development, cytokine release and cell death. Although these receptors interact the interacting domains are unknown and the functional consequences of this interaction remain unclear. Here we show by co-immunoprecipitation that P2X4 interacts with the C-terminus of P2X7 and by fluorescence resonance energy transfer experiments that this receptor-receptor interaction is driven by ATP. Furthermore, disrupting the ATP-driven interaction by knocking-out P2X4R provoked an attenuation of P2X7-induced cell death, dye uptake and IL-1β release in macrophages. Thus, P2X7 interacts with P2X4 via its C-terminus and disrupting the P2X7/P2X4 interaction hinders physiological responses in immune cells.
Insights
The P2X7 receptor interacts with the P2X4 receptor via its C-terminus, an ATP-dependent interaction. Disrupting this interaction in immune cells reduces cell death and cytokine release.
Area of Science:
- Cellular biology
- Immunology
- Neuroscience
Background:
- P2X4 and P2X7 receptors are ATP-gated cation channels.
- They are co-expressed in various cell types and implicated in pain, bone development, and immune responses.
- The interaction domains and functional consequences of P2X4/P2X7 co-expression are not well understood.
Purpose of the Study:
- To investigate the interaction between P2X4 and P2X7 receptors.
- To determine the functional impact of this interaction on cellular responses, particularly in immune cells.
Main Methods:
- Co-immunoprecipitation assays to identify interacting domains.
- Fluorescence resonance energy transfer (FRET) experiments to confirm ATP-driven interaction.
- Gene knockout of P2X4R to disrupt the interaction and assess functional consequences.
Main Results:
- P2X4 receptor directly interacts with the C-terminus of the P2X7 receptor.
- This interaction is mediated and driven by ATP binding.
- Knocking out P2X4R significantly attenuated P2X7-induced cell death, dye uptake, and IL-1β release in macrophages.
- The P2X7/P2X4 interaction is crucial for physiological responses in immune cells.
Conclusions:
- P2X7 and P2X4 receptors interact via the C-terminus of P2X7.
- ATP binding is essential for mediating this receptor-receptor interaction.
- Disruption of the P2X7/P2X4 interaction impairs key immune cell functions, including cell death and cytokine release.
