Protein kinase-X interacts with Pin-1 and Polycystin-1 during mouse kidney development.
The regulation of epithelial branching morphogenesis by bone morphogenetic protein-7 depends, in part, on functionally defined cyclic adenosine monophosphate (cAMP)-dependent protein kinases. We previously identified protein kinase-X (PRKX), a cAMP-dependent kinase, as a regulator of epithelial morphogenesis during kidney development and found that it binds to and phosphorylates Polycystin-1. Overexpression of PRKX stimulates renal epithelial cell migration, tubulogenesis, ureteric bud branching, and glomerular induction in embryonic mouse kidney explants in organ cultures. Here we determined the physiological functions of endogenous PRKX. Knockdown by siRNA of PRKX gene expression in a human fetal collecting tubule (HFCT) cell line exceeded 70% and resulted in decreased cell migration and increased adhesion of the cells to a collagen I matrix. In embryonic mouse kidney explants, the same degree of knockdown decreased ureteric bud branching and glomerular induction. Because PRKX BAG-3 PIN-1 and MAGI-1 are all expressed in ureteric bud derivatives, we tested for interactions among them and found that PRKX binds to all three proteins through its WW domain as determined by TransSignal domain arrays, and it coimmunoprecipitated with Pin-1 in HFCT cell lysates. These studies suggest that Polycystin-1 and Pin-1 may mediate the function of PRKX in kidney development.
Li
Xiaohong
X
Department of Medicine, Mount Sinai School of Medicine, New York, New York 10029, USA. xiaohong.li@mssm.edu
Hyink
Deborah P
DP
Radbill
Brian
B
Sudol
Marius
M
Zhang
Haojiang
H
Zheleznova
Nadezda N
NN
Wilson
Patricia D
PD
D000818:Animals; D002448:Cell Adhesion / Q000235:genetics; D002465:Cell Movement / Q000235:genetics; D017868:Cyclic AMP-Dependent Protein Kinases / Q000378:metabolism*; D005260:Female; D007668:Kidney / Q000166:cytology* / Q000196:embryology*; D051379:Mice; D009024:Morphogenesis / Q000235:genetics; D000072340:NIMA-Interacting Peptidylprolyl Isomerase; D009924:Organ Culture Techniques; D019696:Peptidylprolyl Isomerase / Q000378:metabolism*; D011247:Pregnancy; D011494:Protein Kinases / Q000378:metabolism*; D017346:Protein Serine-Threonine Kinases; D050396:TRPP Cation Channels / Q000378:metabolism*
D017868:Cyclic AMP-Dependent Protein Kinases; D000072340:NIMA-Interacting Peptidylprolyl Isomerase; D019696:Peptidylprolyl Isomerase; D011494:Protein Kinases; D017346:Protein Serine-Threonine Kinases; D050396:TRPP Cation Channels; C543855:PRKX protein, mouse; C000606846:PIN1 protein, human; C000606850:Pin1 protein, mouse