Abstract
Autosomal dominant polycystic kidney disease (ADPKD) is a common heritable disease affecting over 1:1000 of the population worldwide. In Arabian Gulf nations, the frequency of cystic kidney disease is 4.81%. ADPKD is caused by mutations in the PKD1 or PKD2 genes, which encode for the polycystin-1 and polycystin-2 proteins, respectively. It is characterized by increased cell proliferation, the perturbation of the extracellular matrix, and altered cellular polarity. The outcome of these changes is the formation of cysts. Mutations in the PKD1 gene are responsible for 85% of ADPKD cases. Polycystin-1 contains a number of well-defined protein motifs in its extracellular region. It has been previously shown that LRR and the lectin-like region in the extracellular domain of polycystin-1 interact with extracellular matrix components. In this study, we investigated the molecular expression mechanisms and predicted the molecular structure of the GPS domain that could interact with extracellular matrix proteins to assess its potential importance in the etiology and future treatment of ADPKD. To achieve this goal, GPS were amplified from genomic DNA and cloned into the expression vector PET 21-alpha as a His-fusion protein. The cloning and expression were successful, and we achieved high similarity between our cloned GPS domain and the theoretical sequences of the GPS domain in humans.