Analysis of the REJ Module of Polycystin-1 Using Molecular Modeling and Force-Spectroscopy Techniques
Figure 1
(a) Diagram of the predicted domain architecture of the extracellular region of PC1. The ectodomain has a large collection of domains: several leucine-rich repeats (LRR), a C-type lectin domain ((CLD) blue box), an low-density-lipoprotein-like domain ((LDL-A domain) purple octagon), 16 PKD domains (boxes in orange), and the 1000 aa long Receptor for Egg Jelly (REJ), in purple) region. GPS: G-protein coupled proteolytic site. TM: transmembrane domains. (b) Sequence alignments of the putative REJ domains with template structures of the human PKD domain no. 1 from polycystin-1 (1b4r) and the human PKD domain from protein KIAA0319 (2e7m). The arrows indicate beta-stranded secondary structure regions and are derived from the predicted secondary structure of 1b4r as calculated by the DSS algorithm in PyMol. The predicted secondary structure for 2e7m shares similar characteristics. The color of the various amino acids in the alignment reflects the chemical composition of the residues in the REJ fold, for example, red = acidic, blue = basic, and green = hydrophobic. (c) Homology models of putative FNIII domains within the REJ module of human PC1. The conserved Trp residue in REJd1, -d2, and -d3 is shown in purple.
