Differential expression of Cux-1 and p21 in polycystic kidneys from Pkd1 null and cpk mice.

Background: Cux-1 is a murine homeodomain protein that functions as a cell cycle-dependent transcriptional repressor in proliferating cells. Targets of Cux-1 repression include the cyclin kinase inhibitors p21 and p27. In the kidney, Cux-1 is spatially and temporally regulated, and ectopic expression of Cux-1 in transgenic mice results in renal hyperplasia.