TRPV4 channel activity is modulated by direct interaction of the ankyrin domain to PI(4,5)P2

Abstract

Mutations in the ankyrin repeat domain (ARD) of TRPV4 are responsible for several channelopathies, including Charcot-Marie-Tooth disease type 2C and congenital distal and scapuloperoneal spinal muscular atrophy. However, the molecular pathogenesis mediated by these mutations remains elusive, mainly due to limited understanding of the TRPV4 ARD function. Here we show that phosphoinositide binding to the TRPV4 ARD leads to suppression of the channel activity. Among the phosphoinositides, phosphatidylinositol-4,5-bisphosphate (PI(4,5)P 2 ) most potently binds to the TRPV4 ARD. The crystal structure of the TRPV4 ARD in complex with inositol-1,4,5-trisphosphate, the head-group of PI(4,5)P 2 , and the molecular-dynamics simulations revealed the PI(4,5)P 2 -binding amino-acid residues. The TRPV4 channel activities were increased by titration or hydrolysis of membrane PI(4,5)P 2 . Notably, disease-associated TRPV4 mutations that cause a gain-of-function phenotype abolished PI(4,5)P 2 binding and PI(4,5)P 2 sensitivity. These findings identify TRPV4 ARD as a lipid-binding domain in which interactions with PI(4,5)P 2 normalize the channel activity in TRPV4.

Phosphoinositide regulation of TRPV1 revisited

“…6), one in the distal C-terminus, identical to the inhibitory binding site, described earlier (777–820), one in the proximal C-terminus (688–718), overlapping with that discussed in the previous paragraph, and one in the N-terminal Ankyrin-repeat domains (ARD) (189–221) that overlaps with a previously identified calmodulin binding site [58]. The N-terminal binding site does not face the plasma membrane in the structure, but a PI(4,5)P 2 binding region in a similar position was proposed recently in TRPV4, based on the co-crystal structure of the ARD of the chicken TRPV4 and IP 3 , the head group of PI(4,5)P 2 [116]. …”

Screening of Transient Receptor Potential Canonical Channel Activators Identifies Novel Neurotrophic Piperazine Compounds

“…Plasmids of the pCI-neo vector carrying mouse TRPC1a, TRPC2, TRPC3, TRPC4b, TRPC5, TRPC6, and TRPC7 cDNA were used as previously described (Okada et al, 1999;Inoue et al, 2001;Yoshida et al, 2006;Kiyonaka et al, 2009). Plasmids of the pCI-neo vector carrying mouse TRPA1, TRPM2, rat TRPV1, and human TRPV4 cDNA were used as previously described (Hara et al, 2002;Yoshida et al, 2006;Takahashi et al, 2014). A pEF-BOS expression vector encoding human muscarinic type 1 receptor was provided by T. Haga (Gakushuin University, Tokyo, Japan).…”

Regulation of thermoTRPs by lipids

“…8 Activation of TRPV1 by temperatures near 42 C as well as by pungent compounds such as capsaicin, resiniferatoxin and allicin, 8,9 makes this channel an important target in the pathway of pain generation. PIP 2 has been reported to modulate the activity of TRPV1 in an intricate fashion.…”

“…42 In light of these contrasting results, further work will be required to determine the role of PIP2 on the activity of the TRPV4 channel.…”

“…TRPV4 is a channel activated by temperatures that range from [27][28][29][30][31][32][33][34][35][36][37][38][39][40][41][42] C, by changes in osmotic pressure and by molecules of a lipid nature which are downstream of the activity of PLC, 39 among others. In this case, binding of PIP2 to the N-terminus of TRPV4 was shown to be important for activation of the channel by heat and hypotonic stimuli.…”