The PKD1 gene provides instructions for making a protein called polycystin-1. This protein is most active in kidney cells before birth; much less of the protein is made in normal adult kidneys. Although its exact function is not well understood, polycystin-1 appears to interact with a smaller, somewhat similar protein called polycystin-2.
Polycystin-1 spans the cell membrane of kidney cells, so that one end of the protein remains inside the cell and the other end projects from the outer surface of the cell. This positioning of the protein allows it to interact with other proteins, carbohydrates, and fat molecules (lipids) outside the cell and to receive signals that help the cell respond to its environment. When a molecule binds to polycystin-1 on the surface of the cell, the protein interacts with polycystin-2 to trigger a cascade of chemical reactions inside the cell. These chemical reactions instruct the cell to undergo certain changes, such as maturing to take on specialized functions. Polycystin-1 and polycystin-2 likely work together to help regulate cell growth and division (proliferation), cell movement (migration), and interactions with other cells.
Polycystin-1 is also found in cell structures called primary cilia. Primary cilia are tiny, fingerlike projections that line the small tubes where urine is formed (renal tubules). Researchers believe that primary cilia sense the movement of fluid through these tubules, which appears to help maintain the tubules' size and structure. The interaction of polycystin-1 and polycystin-2 in renal tubules promotes the normal development and function of the kidneys.
Health Conditions Related to Genetic Changes
Polycystic kidney disease
More than 250 mutations in the PKD1 gene have been identified in people with polycystic kidney disease. These mutations are responsible for about 85 percent of cases of autosomal dominant polycystic kidney disease (ADPKD), which is the most common type of this disorder. Mutations in the PKD1 gene include deletions or insertions of DNA building blocks (base pairs) and alterations of one or more base pairs. Most PKD1 mutations are predicted to produce an abnormally small, nonfunctional version of the polycystin-1 protein. Although researchers are uncertain how a lack of polycystin-1 leads to the formation of cysts, it probably disrupts the protein's signaling function within the cell and in primary cilia. As a result, cells lining the renal tubules may grow and divide abnormally, leading to the growth of numerous cysts characteristic of polycystic kidney disease.More About This Health Condition
Other Names for This Gene
- polycystic kidney disease 1 (autosomal dominant)
Additional Information & Resources
Tests Listed in the Genetic Testing Registry
Scientific Articles on PubMed
Catalog of Genes and Diseases from OMIM
- Al-Bhalal L, Akhtar M. Molecular basis of autosomal dominant polycystic kidney disease. Adv Anat Pathol. 2005 May;12(3):126-33. Review. Citation on PubMed
- Bissler JJ, Dixon BP. A mechanistic approach to inherited polycystic kidney disease. Pediatr Nephrol. 2005 May;20(5):558-66. Epub 2005 Feb 18. Review. Citation on PubMed
- Boucher C, Sandford R. Autosomal dominant polycystic kidney disease (ADPKD, MIM 173900, PKD1 and PKD2 genes, protein products known as polycystin-1 and polycystin-2). Eur J Hum Genet. 2004 May;12(5):347-54. Review. Citation on PubMed
- Harris PC, Torres VE. Polycystic Kidney Disease, Autosomal Dominant. 2002 Jan 10 [updated 2018 Jul 19]. In: Adam MP, Ardinger HH, Pagon RA, Wallace SE, Bean LJH, Stephens K, Amemiya A, editors. GeneReviews® [Internet]. Seattle (WA): University of Washington, Seattle; 1993-2020. Available from http://www.ncbi.nlm.nih.gov/books/NBK1246/ Citation on PubMed
- Horie S. ADPKD: molecular characterization and quest for treatment. Clin Exp Nephrol. 2005 Dec;9(4):282-291. doi: 10.1007/s10157-005-0367-6. Review. Citation on PubMed
- Lina F, Satlinb LM. Polycystic kidney disease: the cilium as a common pathway in cystogenesis. Curr Opin Pediatr. 2004 Apr;16(2):171-6. Review. Citation on PubMed
- Nauli SM, Alenghat FJ, Luo Y, Williams E, Vassilev P, Li X, Elia AE, Lu W, Brown EM, Quinn SJ, Ingber DE, Zhou J. Polycystins 1 and 2 mediate mechanosensation in the primary cilium of kidney cells. Nat Genet. 2003 Feb;33(2):129-37. Epub 2003 Jan 6. Citation on PubMed
- Nauli SM, Rossetti S, Kolb RJ, Alenghat FJ, Consugar MB, Harris PC, Ingber DE, Loghman-Adham M, Zhou J. Loss of polycystin-1 in human cyst-lining epithelia leads to ciliary dysfunction. J Am Soc Nephrol. 2006 Apr;17(4):1015-25. Citation on PubMed
- Ong AC, Harris PC. Molecular pathogenesis of ADPKD: the polycystin complex gets complex. Kidney Int. 2005 Apr;67(4):1234-47. Citation on PubMed
- Wilson PD. Polycystic kidney disease. N Engl J Med. 2004 Jan 8;350(2):151-64. Review. Citation on PubMed