Proc Natl Acad Sci U S A. 2008 Oct 14;105(41):15920-5. doi: 10.1073/pnas.0805062105. Epub 2008 Oct 3.

Syntaxin 5 regulates the endoplasmic reticulum channel-release properties of polycystin-2.External 2231691f894ba696de1310221b0a0dbbb31a7251e75115c265587c3d9d5f507c

Geng, L., Boehmerle, W., Maeda, Y., Okuhara, D. Y., Tian, X., Yu, Z., Choe, C. U., Anyatonwu, G. I., Ehrlich, B. E., Somlo, S.,
["Department of Internal Medicine, Yale University School of Medicine, New Haven, CT 06510, USA."]
Polycystin-2 (PC2), the gene product of one of two genes mutated in dominant polycystic kidney disease, is a member of the transient receptor potential cation channel family and can function as intracellular calcium (Ca(2+)) release channel. We performed a yeast two-hybrid screen by using the NH(2) terminus of PC2 and identified syntaxin-5 (Stx5) as a putative interacting partner. Coimmunoprecipitation studies in cell lines and kidney tissues confirmed interaction of PC2 with Stx5 in vivo. In vitro binding assays showed that the interaction between Stx5 and PC2 is direct and defined the respective interaction domains as the t-SNARE region of Stx5 and amino acids 5 to 72 of PC2. Single channel studies showed that interaction with Stx5 specifically reduces PC2 channel activity. Epithelial cells overexpressing mutant PC2 that does not bind Stx5 had increased baseline cytosolic Ca(2+) levels, decreased endoplasmic reticulum (ER) Ca(2+) stores, and reduced Ca(2+) release from ER stores in response to vasopressin stimulation. Cells lacking PC2 altogether had reduced cytosolic Ca(2+) levels. Our data suggest that PC2 in the ER plays a role in cellular Ca(2+) homeostasis and that Stx5 functions to inactivate PC2 and prevent leaking of Ca(2+) from ER stores. Modulation of the PC2/Stx5 interaction may be a useful target for impacting dysregulated intracellular Ca(2+) signaling associated with polycystic kidney disease.
PMID: 18836075External 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
TRPP1 Link 2bd4d11adb659cddf58197a94e201f0a44c55d8d7cb427c624971b42e122c0a4 Syntaxin5 Yeast two-hybrid Human 3-213 Mouse Embryonic cDNA library 18836075
(Link 2bd4d11adb659cddf58197a94e201f0a44c55d8d7cb427c624971b42e122c0a4: click the arrow icon to show interactions only between the corresponding TRP channel and the interactor)
Validation: In vitro validation Toggle 893349bafcc528f8346c51dc3420151d67b0126b2c122dd1017121c03fa0f69b
  Assay with recombinant proteins Reference
TRP channel construct Interactor construct
TRP channel Interactor Method Species Region Expression system Species Region Expression system
TRPP1 Link 2bd4d11adb659cddf58197a94e201f0a44c55d8d7cb427c624971b42e122c0a4 Syntaxin5 Fusion protein-pull down assay Human 3-213 E. coli Mouse Full-length Not specified 18836075
(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
TRPP1 Link 2bd4d11adb659cddf58197a94e201f0a44c55d8d7cb427c624971b42e122c0a4 Syntaxin5 Co-immunoprecipitation LLC-PK1 Human Full-length Mouse Full-length 18836075
TRPP1 Link 2bd4d11adb659cddf58197a94e201f0a44c55d8d7cb427c624971b42e122c0a4 Syntaxin5 Co-immunofluorescence staining LLC-PK1 Human Full-length Mouse Full-length 18836075
(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
TRPP1 Link 2bd4d11adb659cddf58197a94e201f0a44c55d8d7cb427c624971b42e122c0a4 Syntaxin5 Fusion protein-pull down assay Human Not determined Mouse 256-333 18836075
TRPP1 Link 2bd4d11adb659cddf58197a94e201f0a44c55d8d7cb427c624971b42e122c0a4 Syntaxin5 Co-immunoprecipitation Human 5-72 Mouse Not determined 18836075
(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
TRPP1 Link 2bd4d11adb659cddf58197a94e201f0a44c55d8d7cb427c624971b42e122c0a4 Syntaxin5 Patch clamp Inhibition 18836075
(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.