Extracellular ATP induces formation of AP-1 complexes in astrocytes via P2 purinoceptors.

The transcription activator protein-1 (AP-1) complex is a heterodimer consisting of Fos and Jun family members. We found that extracellular ATP stimulated AP-1 DNA binding activity in cerebral cortical astrocyte cultures. This activity was maximal at 1 h and persisted for at least 3 h post-treatment. Shift-Western blotting indicated the presence of c-Fos in the AP-1 complexes. Stimulation of AP-1 binding by ATP was due to activation of P2 rather than P1 purinoceptors. The protein kinase C (PKC) inhibitor Ro 31-8220 markedly reduced P2 purinoceptor-mediated AP-1 induction. The induction of AP-1 complexes by ATP may contribute to changes in gene expression which underlie the trophic effects of extracellular ATP on astrocytes.