Structural basis of TRPV5 regulation by physiological and pathophysiological modulators

Edwin C. Fluck, Aysenur Torun Yazici, Tibor Rohacs, Vera Y. Moiseenkova-Bell

Research output: Contribution to journalArticlepeer-review

7 Scopus citations

Abstract

Transient receptor potential vanilloid 5 (TRPV5) is a kidney-specific Ca2+-selective ion channel that plays a key role in Ca2+ homeostasis. The basal activity of TRPV5 is balanced through activation by phosphatidylinositol 4,5-bisphosphate (PI(4,5)P2) and inhibition by Ca2+-bound calmodulin (CaM). Parathyroid hormone (PTH), the key extrinsic regulator of Ca2+ homeostasis, increases the activity of TRPV5 via protein kinase A (PKA)-mediated phosphorylation. Metabolic acidosis leads to reduced TRPV5 activity independent of PTH, causing hypercalciuria. Using cryoelectron microscopy (cryo-EM), we show that low pH inhibits TRPV5 by precluding PI(4,5)P2 activation. We capture intermediate conformations at low pH, revealing a transition from open to closed state. In addition, we demonstrate that PI(4,5)P2 is the primary modulator of channel gating, yet PKA controls TRPV5 activity by preventing CaM binding and channel inactivation. Our data provide detailed molecular mechanisms for regulation of TRPV5 by two key extrinsic modulators, low pH and PKA.

Original languageEnglish (US)
Article number110737
JournalCell Reports
Volume39
Issue number4
DOIs
StatePublished - Apr 26 2022

All Science Journal Classification (ASJC) codes

  • Biochemistry, Genetics and Molecular Biology(all)

Keywords

  • CP: Molecular biology
  • CP: Neuroscience
  • CaM
  • PI(4,5)P
  • PKA
  • TRP channel
  • calmodulin
  • cryo-EM
  • cryoelectron microscopy
  • pH
  • protein kinase A
  • transient receptor potential channel

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