Fig. 6. A highly conserved patch in the N-terminal TRPV4 IDR transiently interacts with the C-terminal PIP₂ binding site and autoinhibits TRPV4 function.

a Chemical shift differences at high and low salt between ¹⁵N-labeled native IDR and IDR^AAWAA with a mutated PIP₂ binding site (PBS) shows that mutagenesis of the PBS leads to chemical shift changes in the conserved N-terminal patch. At the higher salt concentration (light gray), these chemical shift perturbations are significantly reduced. b Degree of conservation in TRPV4 IDR determined with ConSurf⁵⁰ (Supplementary Fig. 11). c Chemical shift differences at high and low salt between ¹⁵N-labeled IDR and IDR^Patch with a mutation in the conserved N-terminal patch shows that mutagenesis leads to chemical shift changes in the PBS. At the higher salt concentration (light gray), these chemical shift perturbations are significantly reduced. d Relative peak intensity of IDR, IDR^AAWAA and IDR^Patch residues in the isolated IDR or in context of the ARD (i.e., NTD, NTD^AAWAA or NTD^Patch). All protein concentrations used were 100 µM. A value of 0.5 indicates that peak intensities for a respective IDR residue are halved when the ARD is present, a value of zero represents complete line broadening in the context of the NTD. Accordingly, lower values are indicative of IDR/ARD interactions. e, f Ca²⁺ imaging of hsTRPV4 variants expressed in MN-1 cells. e Basal Ca²⁺ and f hypotonic treatment at t = 20 s show increased activity of the patch mutant. For better comparison, data for TRPV4^ΔN68 are replotted from Fig. 5h, i. Data in e are presented as mean values ± SEM from n = 13 (TRPV4), 11 (TRPV4^ΔN68), 14 (TRPV4^Patch) and in f from n = 12 (TRPV4, TRPV4^ΔN68, and TRPV4^Patch) biologically independent experiments, each with 10–30 cells per field of view. Source data are provided as a Source Data file.