Figure 5.

The N terminus of TRPV4 is essential for the directionality of the volume sensing. A and B, schematics of the constructed chimeras (top) with the N terminus from TRPV1 (left) and the TRPV1 splice variant VR.5′sv (right) and micrographs of the chimeras immunolabeled with phalloidin and anti-AQP4 and anti-TRPV4 antibodies, confirming plasma membrane expression. C and D, summarized I/V curves from TRPV4:TRPV1-expressing (C) or TRPV4:VR.5′sv-expressing (D) oocytes with control solution (black), hyposmotic solution (red), hyperosmotic solution (orange), GSK101 (TRPV4 agonist; green), and capsaicin (TRPV1 agonist; gray). Activity from uninjected oocytes is shown in Ci. Insets, current activity at −85 mV obtained after exposure to −100 mosm, +100 mosm, GSK101, or capsaicin was normalized to that obtained in control conditions. N.S., not significant (p > 0.05); ***, p < 0.001; one-way ANOVA, n = 12 oocytes. Error bars, S.D. (bar graphs) or S.E. (I/V curves).