EMBO J. 2005 Feb 23;24(4):705-16. Epub 2005 Feb 3.
Trafficking of TRPP2 by PACS proteins represents a novel mechanism of ion channel regulation.
Kottgen, M., Benzing, T., Simmen, T., Tauber, R., Buchholz, B., Feliciangeli, S., Huber, T. B., Schermer, B., Kramer-Zucker, A., Hopker, K., Simmen, K. C., Tschucke, C. C., Sandford, R., Kim, E., Thomas, G., Walz, G.,
["Renal Division, University Hospital of Freiburg, Freiburg, Germany."]
["Renal Division, University Hospital of Freiburg, Freiburg, Germany."]
The trafficking of ion channels to the plasma membrane is tightly controlled to ensure the proper regulation of intracellular ion homeostasis and signal transduction. Mutations of polycystin-2, a member of the TRP family of cation channels, cause autosomal dominant polycystic kidney disease, a disorder characterized by renal cysts and progressive renal failure. Polycystin-2 functions as a calcium-permeable nonselective cation channel; however, it is disputed whether polycystin-2 resides and acts at the plasma membrane or endoplasmic reticulum (ER). We show that the subcellular localization and function of polycystin-2 are directed by phosphofurin acidic cluster sorting protein (PACS)-1 and PACS-2, two adaptor proteins that recognize an acidic cluster in the carboxy-terminal domain of polycystin-2. Binding to these adaptor proteins is regulated by the phosphorylation of polycystin-2 by the protein kinase casein kinase 2, required for the routing of polycystin-2 between ER, Golgi and plasma membrane compartments. Our paradigm that polycystin-2 is sorted to and active at both ER and plasma membrane reconciles the previously incongruent views of its localization and function. Furthermore, PACS proteins may represent a novel molecular mechanism for ion channel trafficking, directing acidic cluster-containing ion channels to distinct subcellular compartments.
PMID: 15692563
 Screening
Validation: In vitro validation
Validation: In vivo validation
Characterization
Functional consequence
|
top
|
Screening
|
||||||||||
|---|---|---|---|---|---|---|---|---|---|---|
| Experimental screening | Non-experimental screening | Reference | ||||||||
| TRP channel construct | Interactor source | |||||||||
| TRP channel | Interactor | Method | Species | Region | Species | Organ/tissue | Sample type | |||
| TRPP1 |
|
ƣ-adaptin | Inference | Prediction | 15692563 | |||||
| TRPP1 |
|
PACS-1 | Inference | Prediction | 15692563 | |||||
| TRPP1 |
|
PACS-2 | Inference | Prediction | 15692563 | |||||
| TRPV4 |
|
PACS-1 | Inference | Prediction | 15692563 | |||||
(:
click the arrow icon to show interactions only between the corresponding TRP channel and the interactor)
:
click the arrow icon to show interactions only between the corresponding TRP channel and the interactor)
|
Screening
Validation: In vitro validation
Validation: In vivo validation
Characterization
Functional consequence
|
top
|
| Validation: In vitro validation
|
||||||||||
|---|---|---|---|---|---|---|---|---|---|---|
| Assay with recombinant proteins | Reference | |||||||||
| TRP channel construct | Interactor construct | |||||||||
| TRP channel | Interactor | Method | Species | Region | Expression system | Species | Region | Expression system | ||
| TRPP1 |
|
PACS-1 | Fusion protein-pull down assay | Human | Full-length | HEK293T lysates | Human | Full-length | Not specified | 15692563 |
| TRPP1 |
|
PACS-1 | Fusion protein-pull down assay | Not used | Mouse kidney tissue lysates | Human | Full-length | Not specified | 15692563 | |
| TRPP1 |
|
PACS-2 | Fusion protein-pull down assay | Human | Full-length | HEK293T lysates | Human | Full-length | Not specified | 15692563 |
(:
click the arrow icon to show interactions only between the corresponding TRP channel and the interactor)
:
click the arrow icon to show interactions only between the corresponding TRP channel and the interactor)
|
Screening
Validation: In vitro validation
Validation: In vivo validation
Characterization
Functional consequence
|
top
|
| Validation: In vivo validation
|
||||||||||
|---|---|---|---|---|---|---|---|---|---|---|
| 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 |
|
ƣ-adaptin | Co-immunoprecipitation | COS M6 kidney cell | 15692563 | |||||
| TRPP1 |
|
PACS-1 | Co-immunoprecipitation | COS M6 kidney cell | 15692563 | |||||
| TRPP1 |
|
PACS-2 | Co-immunoprecipitation | COS M6 kidney cell | 15692563 | |||||
| TRPV4 |
|
PACS-1 | Co-immunoprecipitation | HEK293T | Human | Full-length | Human | Full-length | 15692563 | |
(:
click the arrow icon to show interactions only between the corresponding TRP channel and the interactor)
:
click the arrow icon to show interactions only between the corresponding TRP channel and the interactor)
|
Screening
Validation: In vitro validation
Validation: In vivo validation
Characterization
Functional consequence
|
top
|
| Characterization
|
||||||||||
|---|---|---|---|---|---|---|---|---|---|---|
| Binding region mapping | Stoichiometry | Affinity (Kd) | Reference | |||||||
| TRP channel | Interactor | |||||||||
| TRP channel | Interactor | Method | Species | Region | Species | Region | ||||
| TRPP1 |
|
PACS-1 | Fluorescence probe labeling | 14.8 ƬM | 15692563 | |||||
| TRPP1 |
|
PACS-1 | Fusion protein-pull down assay | Human | 741-871 | Human | 115-255 | 15692563 | ||
| TRPP1 |
|
PACS-2 | Fusion protein-pull down assay | Human | Not determined | Human | 117-266 | 15692563 | ||
| TRPP1 |
|
PACS-2 | Fluorescence probe labeling | 15.4 ƬM | 15692563 | |||||
| TRPP1 |
|
PKD1/Polycystin-1 | Fusion protein-pull down assay | Human | 681-968 | Not specified | 4077-4302 | 15692563 | ||
| TRPV4 |
|
PACS-1 | Co-immunoprecipitation | Human | 1-486 | Human | Not determined | 15692563 | ||
(:
click the arrow icon to show interactions only between the corresponding TRP channel and the interactor)
:
click the arrow icon to show interactions only between the corresponding TRP channel and the interactor)