J Biol Chem. 2009 Dec 4;284(49):34400-12. doi: 10.1074/jbc.M109.015149. Epub 2009 Oct 7.

A pathogenic C terminus-truncated polycystin-2 mutant enhances receptor-activated Ca2+ entry via association with TRPC3 and TRPC7.External 2231691f894ba696de1310221b0a0dbbb31a7251e75115c265587c3d9d5f507c

Miyagi, K., Kiyonaka, S., Yamada, K., Miki, T., Mori, E., Kato, K., Numata, T., Sawaguchi, Y., Numaga, T., Kimura, T., Kanai, Y., Kawano, M., Wakamori, M., Nomura, H., Koni, I., Yamagishi, M., Mori, Y.,
["Department of Synthetic Chemistry and Biological Chemistry, Graduate School of Engineering, Kyoto University, Japan."]
Mutations in PKD2 gene result in autosomal dominant polycystic kidney disease (ADPKD). PKD2 encodes polycystin-2 (TRPP2), which is a homologue of transient receptor potential (TRP) cation channel proteins. Here we identify a novel PKD2 mutation that generates a C-terminal tail-truncated TRPP2 mutant 697fsX with a frameshift resulting in an aberrant 17-amino acid addition after glutamic acid residue 697 from a family showing mild ADPKD symptoms. When recombinantly expressed in HEK293 cells, wild-type (WT) TRPP2 localized at the endoplasmic reticulum (ER) membrane significantly enhanced Ca(2+) release from the ER upon muscarinic acetylcholine receptor (mAChR) stimulation. In contrast, 697fsX, which showed a predominant plasma membrane localization characteristic of TRPP2 mutants with C terminus deletion, prominently increased mAChR-activated Ca(2+) influx in cells expressing TRPC3 or TRPC7. Coimmunoprecipitation, pulldown assay, and cross-linking experiments revealed a physical association between 697fsX and TRPC3 or TRPC7. 697fsX but not WT TRPP2 elicited a depolarizing shift of reversal potentials and an enhancement of single-channel conductance indicative of altered ion-permeating pore properties of mAChR-activated currents. Importantly, in kidney epithelial LLC-PK1 cells the recombinant 679fsX construct was codistributed with native TRPC3 proteins at the apical membrane area, but the WT construct was distributed in the basolateral membrane and adjacent intracellular areas. Our results suggest that heteromeric cation channels comprised of the TRPP2 mutant and the TRPC3 or TRPC7 protein induce enhanced receptor-activated Ca(2+) influx that may lead to dysregulated cell growth in ADPKD.
PMID: 19812035External 2231691f894ba696de1310221b0a0dbbb31a7251e75115c265587c3d9d5f507c
Screening Toggle 893349bafcc528f8346c51dc3420151d67b0126b2c122dd1017121c03fa0f69b
  Experimental screening Non-experimental screening Reference
TRP channel construct Interactor source
TRP channel Interactor Method Species Region Species Organ/tissue Sample type
TRPC3 Link 2bd4d11adb659cddf58197a94e201f0a44c55d8d7cb427c624971b42e122c0a4 TRPP1 Inference Prediction 19812035
TRPC7 Link 2bd4d11adb659cddf58197a94e201f0a44c55d8d7cb427c624971b42e122c0a4 TRPP1 Inference Prediction 19812035
TRPP1 Link 2bd4d11adb659cddf58197a94e201f0a44c55d8d7cb427c624971b42e122c0a4 TRPC3 Inference Prediction 19812035
TRPP1 Link 2bd4d11adb659cddf58197a94e201f0a44c55d8d7cb427c624971b42e122c0a4 TRPC7 Inference Prediction 19812035
(Link 2bd4d11adb659cddf58197a94e201f0a44c55d8d7cb427c624971b42e122c0a4: click the arrow icon to show interactions only between the corresponding TRP channel and the interactor)
Validation: In vivo validation Toggle 893349bafcc528f8346c51dc3420151d67b0126b2c122dd1017121c03fa0f69b
  Assay with endogenous proteins Assay with overexpressed proteins Reference
Cell or tissue Cell or tissue TRP channel construct Interactor construct
TRP channel Interactor Method Species Region Species Region
TRPC1 Link 2bd4d11adb659cddf58197a94e201f0a44c55d8d7cb427c624971b42e122c0a4 TRPP1 Co-immunoprecipitation HEK293 Mouse Full-length Human Full-length 19812035
TRPC3 Link 2bd4d11adb659cddf58197a94e201f0a44c55d8d7cb427c624971b42e122c0a4 TRPP1 Co-immunoprecipitation HEK293 Mouse Full-length Human 1-697 19812035
TRPC3 Link 2bd4d11adb659cddf58197a94e201f0a44c55d8d7cb427c624971b42e122c0a4 TRPP1 Co-immunofluorescence staining LLC-PK1 Not used Human 1-697 19812035
TRPC7 Link 2bd4d11adb659cddf58197a94e201f0a44c55d8d7cb427c624971b42e122c0a4 TRPP1 Co-immunoprecipitation HEK293 Mouse Full-length Human 1-697 19812035
TRPP1 Link 2bd4d11adb659cddf58197a94e201f0a44c55d8d7cb427c624971b42e122c0a4 TRPC1 Co-immunoprecipitation HEK293 Human Full-length Mouse Full-length 19812035
TRPP1 Link 2bd4d11adb659cddf58197a94e201f0a44c55d8d7cb427c624971b42e122c0a4 TRPC3 Co-immunoprecipitation HEK293 Human 1-697 Mouse Full-length 19812035
TRPP1 Link 2bd4d11adb659cddf58197a94e201f0a44c55d8d7cb427c624971b42e122c0a4 TRPC3 Co-immunofluorescence staining LLC-PK1 Human 1-697 Not used 19812035
TRPP1 Link 2bd4d11adb659cddf58197a94e201f0a44c55d8d7cb427c624971b42e122c0a4 TRPC7 Co-immunoprecipitation HEK293 Human 1-697 Mouse Full-length 19812035
(Link 2bd4d11adb659cddf58197a94e201f0a44c55d8d7cb427c624971b42e122c0a4: click the arrow icon to show interactions only between the corresponding TRP channel and the interactor)
Characterization Toggle 893349bafcc528f8346c51dc3420151d67b0126b2c122dd1017121c03fa0f69b
  Binding region mapping Stoichiometry Affinity (Kd) Reference
TRP channel Interactor
TRP channel Interactor Method Species Region Species Region
TRPC3 Link 2bd4d11adb659cddf58197a94e201f0a44c55d8d7cb427c624971b42e122c0a4 TRPP1 Fusion protein-pull down assay Mouse 659-753 Human 1-697 19812035
TRPP1 Link 2bd4d11adb659cddf58197a94e201f0a44c55d8d7cb427c624971b42e122c0a4 TRPC3 Fusion protein-pull down assay Human 1-697 Mouse 659-753 19812035
(Link 2bd4d11adb659cddf58197a94e201f0a44c55d8d7cb427c624971b42e122c0a4: click the arrow icon to show interactions only between the corresponding TRP channel and the interactor)
Functional consequence Toggle 893349bafcc528f8346c51dc3420151d67b0126b2c122dd1017121c03fa0f69b
TRP channel Interactor Method Post-translational modification Subcellular trafficking Activity Reference
TRPC3 Link 2bd4d11adb659cddf58197a94e201f0a44c55d8d7cb427c624971b42e122c0a4 TRPP1 Calcium measurement Activation 19812035
TRPC7 Link 2bd4d11adb659cddf58197a94e201f0a44c55d8d7cb427c624971b42e122c0a4 TRPP1 Calcium measurement Activation 19812035
(Link 2bd4d11adb659cddf58197a94e201f0a44c55d8d7cb427c624971b42e122c0a4: click the arrow icon to show interactions only between the corresponding TRP channel and the interactor)
TRP / Interactor

To prevent spam comments, we use reCAPTCHA. Please type correct words into the following box.