![Measurement of current through individual puncta.(A) Plot of the plateau fractional saturation of Orai1-GCaMP6f at puncta in cell E during a 600-ms test pulse to −100 mV. Red line indicates the mean. (B) Map of Orai1-GCaMP6f fractional activation at puncta. Light gray line indicates the edge of the cell footprint. (C) Enlargement of central right portion of B. (D) Plot of plateau [Ca2+] at puncta in cell E. Red line indicates the median. (E) Map of plateau [Ca2+] at puncta. (F) Enlargement of central right portion of E. (G) Plot of Orai1 plateau Ca2+ current through puncta in cell E. Red line indicates the median. (H) Map of Orai1 plateau Ca2+ current at puncta. (I) Enlargement of central right portion of H. (J) Scatterplot of ΔF/F0 versus resting Orai1-GCaMP6f fluorescence intensity (F0) at individual puncta for all six cells. Puncta STIM1:Orai1 ratio was restricted to values between 2 and 3. Linear curve fit (red line) indicates that puncta ΔF/F0 is not related to the number of Orai1-GCaMP6f channels at a punctum (slope = −0.00001, R2 = 0.00002; slope ≠ 0, P = 0.95, F test). Scale bar in B is 10 µm (applies to E and H), and the scale bar in C is 2.5 µm (applies to F and I).](https://cdn.rupress.org/rup/content_public/journal/jgp/152/9/10.1085_jgp.201812239/2/jgp_201812239_fig8.png?Expires=1767755431&Signature=qYUvRz1CVMLPwQHVB0otxNcb4lbnga08rzWz0JXiIvQR7JUsFoNozz6kzHM9S6EJtXPaGOU9npzE3VGM9mb-H5eBwFmyqnjS6nk1npTOmKh909Ws3ULGEiNgf4oax07HwLYt91Zk5t2SqK13Sv-cf3ID9cMitxSmkRy1a2u2Bff9SB94OZpuYbryfXZI-14YsDlvNz0koL0tga7~PUriyS7KbPliEgJudGbvrVGFU8ShKWjAmjL3lZPXJ7gY6W12Hqze8d6WNXQYUzuIB1ZiMiXx6bThlUni14yxYuln5DR~lIT1vlNpgtnlLjQWqWfjlCsoLjuB6LVH0usqZ0chEw__&Key-Pair-Id=APKAIE5G5CRDK6RD3PGA)
Measurement of current through individual puncta. (A) Plot of the plateau fractional saturation of Orai1-GCaMP6f at puncta in cell E during a 600-ms test pulse to −100 mV. Red line indicates the mean. (B) Map of Orai1-GCaMP6f fractional activation at puncta. Light gray line indicates the edge of the cell footprint. (C) Enlargement of central right portion of B. (D) Plot of plateau [Ca2+] at puncta in cell E. Red line indicates the median. (E) Map of plateau [Ca2+] at puncta. (F) Enlargement of central right portion of E. (G) Plot of Orai1 plateau Ca2+ current through puncta in cell E. Red line indicates the median. (H) Map of Orai1 plateau Ca2+ current at puncta. (I) Enlargement of central right portion of H. (J) Scatterplot of ΔF/F0 versus resting Orai1-GCaMP6f fluorescence intensity (F0) at individual puncta for all six cells. Puncta STIM1:Orai1 ratio was restricted to values between 2 and 3. Linear curve fit (red line) indicates that puncta ΔF/F0 is not related to the number of Orai1-GCaMP6f channels at a punctum (slope = −0.00001, R2 = 0.00002; slope ≠ 0, P = 0.95, F test). Scale bar in B is 10 µm (applies to E and H), and the scale bar in C is 2.5 µm (applies to F and I).