Analysis of the cytoplasmic interaction between polycystin-1 and polycystin-2.
Autosomal dominant polycystic kidney disease (ADPKD) arises following mutations of either Pkd1 or Pkd2. The proteins these genes encode, polycystin-1 (PC1) and polycystin-2 (PC2), form a signaling complex using direct intermolecular interactions. Two distinct domains in the C-terminal tail of PC2 have recently been identified, an EF-hand and a coiled-coil domain. Here, we show that the PC2 coiled-coil domain interacts with the C-terminal tail of PC1, but that the PC2 EF-hand domain does not. We measured the K0.5 of the interaction between the C-terminal tails of PC1 and PC2 and showed that the direct interaction of these proteins is abrogated by a PC1 point mutation that was identified in ADPKD patients. Finally, we showed that overexpression of the PC1 C-terminal tail in MDCK cells alters the Ca2+ response, but that overexpression of the PC1 C-terminal tail containing the disease mutation does not. These results allow a more detailed understanding of the mechanism of pathogenic mutations in the cytoplasmic regions of PC1 and PC2.
Casuscelli
Jozefina
J
Department of Pharmacology, Yale University School of Medicine, New Haven, CT 06520-8066, USA.
Schmidt
Stefan
S
DeGray
Brenda
B
Petri
Edward T
ET
Celić
Andjelka
A
Folta-Stogniew
Ewa
E
Ehrlich
Barbara E
BE
Boggon
Titus J
TJ
D000818:Animals; D020013:Calcium Signaling / Q000502:physiology; D002460:Cell Line; D003593:Cytoplasm / Q000502:physiology*; D004285:Dogs; D004847:Epithelial Cells / Q000378:metabolism; D006801:Humans; D051379:Mice; D016891:Polycystic Kidney, Autosomal Dominant / Q000235:genetics; D011487:Protein Conformation; D020349:Surface Plasmon Resonance; D050396:TRPP Cation Channels / Q000235:genetics / Q000502:physiology*; D014162:Transfection
D050396:TRPP Cation Channels