2. Academic Validation
  3. A novel PKD2L1 C-terminal domain critical for trimerization and channel function

A novel PKD2L1 C-terminal domain critical for trimerization and channel function

  • Sci Rep. 2015 Mar 30;5:9460. doi: 10.1038/srep09460.
Wang Zheng 1,  Shaimaa Hussein 1,  JungWoo Yang 1,  Jun Huang 2,  Fan Zhang 3,  Samuel Hernandez-Anzaldo 4,  Carlos Fernandez-Patron 4,  Ying Cao 3,  Hongbo Zeng 2,  Jingfeng Tang 5,  Xing-Zhen Chen 6
Affiliations

Affiliations

  • 1 Membrane Protein Disease Research Group, Department of Physiology, Faculty of Medicine and Dentistry, University of Alberta, T6G 2H7, Edmonton, AB, Canada.
  • 2 Department of Chemical and Materials Engineering, Faculty of Engineering, University of Alberta, T6G 2V4, Edmonton, AB, Canada.
  • 3 School of Life Sciences and Technology, Tongji University, 200092, Shanghai, China.
  • 4 Department of Biochemistry, Faculty of Medicine and Dentistry, University of Alberta, T6G 2H7, Edmonton, AB, Canada.
  • 5 Membrane Protein Disease and Cancer Research Center, Hubei University of Technology, 430068, Wuhan, Hubei, China.
  • 6 1] Membrane Protein Disease Research Group, Department of Physiology, Faculty of Medicine and Dentistry, University of Alberta, T6G 2H7, Edmonton, AB, Canada [2] Membrane Protein Disease and Cancer Research Center, Hubei University of Technology, 430068, Wuhan, Hubei, China.
PMID: 25820328 DOI: 10.1038/srep09460
Abstract

As a transient receptor potential (TRP) superfamily member, polycystic kidney disease 2-like-1 (PKD2L1) is also called TRPP3 and has similar membrane topology as voltage-gated cation channels. PKD2L1 is involved in Hedgehog signaling, intestinal development, and sour tasting. PKD2L1 and PKD1L3 form heterotetramers with 3:1 stoichiometry. C-terminal coiled-coil-2 (CC2) domain (G699-W743) of PKD2L1 was reported to be important for its trimerization but independent studies showed that CC2 does not affect PKD2L1 channel function. It thus remains unclear how PKD2L1 proteins oligomerize into a functional channel. By SDS-PAGE, blue native PAGE and mutagenesis we here identified a novel C-terminal domain called C1 (K575-T622) involved in stronger homotrimerization than the non-overlapping CC2, and found that the PKD2L1 N-terminus is critical for dimerization. By electrophysiology and Xenopus oocyte expression, we found that C1, but not CC2, is critical for PKD2L1 channel function. Our co-immunoprecipitation and dynamic light scattering experiments further supported involvement of C1 in trimerization. Further, C1 acted as a blocking peptide that inhibits PKD2L1 trimerization as well as PKD2L1 and PKD2L1/PKD1L3 channel function. Thus, our study identified C1 as the first PKD2L1 domain essential for both PKD2L1 trimerization and channel function, and suggest that PKD2L1 and PKD2L1/PKD1L3 channels share the PKD2L1 trimerization process.

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