Figure 3.

NPR, NP1, and NARP binding enhances GluA1 function. A, Glutamate-induced currents in HEK293T cells expressing GluA1 without or with neuronal pentraxins. Left, Sample traces. Right, Summary graphs of the peak and plateau amplitudes. Currents were induced by a 2 s application of 10 mm K-glutamate (GluK) to patched HEK293T cells cotransfected with GluA1 and stargazin expression vectors, and with a control plasmid (Ctrl.) or plasmids encoding Flag-tagged neuronal pentaxins. Both NPR and extracellular domains of NPR (NPR-ECD) were used because NPR physiologically binds to GluA1 in trans. B, Same as A, except that HEK cells were transfected only with GluA1 and stargazin expression plasmids, and secreted neuronal pentraxins were added to the medium for 24 h before recordings. Recombinant neuronal pentraxins were obtained in the medium of separately transfected HEK293T cells that secrete the proteins into the medium, using medium from control transfected HEK293T cells as a control. Data are mean ± SEM. Numbers in bars indicate number of HEK293 cells/experiments analyzed. *p < 0.05 (Student's t test). **p < 0.01 (Student's t test). ***p < 0.001 (Student's t test).