Calcium mobilization in Jurkat cells via A2b adenosine receptors.
1. A functional study of cell surface A2b adenosine receptors was performed on the T cell leukaemia line, Jurkat. 2. A2b receptors were coupled both to the adenylate cyclase system and to intracellular calcium channels. In fact, the agonist of A2b receptors, 5'-N-ethylcarboxamidoadenosine (NECA), led to a transient accumulation of intracellular calcium by an inositol phosphate-independent mechanism. 3. The NECA-induced accumulation of cGMP was not responsible for the calcium mobilization via A2b receptors. 4. The calcium response elicited by activation of A2b receptors was independent of that evoked by activation of the T cell receptor. 5. These findings not only delineate a novel transduction mechanism for adenosine but also support a specific role for adenosine in modulating signals elicited via the T cell receptor.
Mirabet
M
M
Departament de Bioquímica i Biologia Molecular, Facultat de Química, Universitat de Barcelona, Catalonia, Spain.
Mallol
J
J
Lluis
C
C
Franco
R
R
D019830:Adenosine-5'-(N-ethylcarboxamide) / Q000494:pharmacology; D002118:Calcium / Q000378:metabolism*; D006152:Cyclic GMP / Q000378:metabolism; D006801:Humans; D007295:Inositol Phosphates / Q000378:metabolism; D019169:Jurkat Cells; D058906:Purinergic P1 Receptor Agonists; D011956:Receptors, Cell Surface / Q000819:agonists / Q000502:physiology; D018047:Receptors, Purinergic P1 / Q000502:physiology*; D015398:Signal Transduction
D007295:Inositol Phosphates; D058906:Purinergic P1 Receptor Agonists; D011956:Receptors, Cell Surface; D018047:Receptors, Purinergic P1; D019830:Adenosine-5'-(N-ethylcarboxamide); D006152:Cyclic GMP; D002118:Calcium