Molecular complexes formed with polycystins.

Polycystins are a family of novel transmembrane proteins with at least six members already identified in humans. Defects in polycystins-1 and -2 are responsible for nearly all cases of autosomal-dominant polycystic kidney disease (ADPKD), a major cause of end-stage renal failure. With the progress made in elucidating the genetic basis of ADPKD, the challenges are to understand the functions of polycystins and to delineate the biochemical and cellular mechanisms of cyst development and progression. In this review, we summarize the recent advances in our knowledge of the functions of polycystins with emphasis on the molecular composition of polycystin protein complexes in the kidney.