Fig. 1. Two-hybrid bait and titin polypeptides identified in the two-hybrid screen. (A) Diagram of the pre-lamin A protein drawn to scale, showing regions encoded by exons 1-12. The exon 8-9 bait polypeptide is underlined (bait). Vertical lines indicate positions of missense mutations that cause EDMD (R527P, R453W), MAD (L530P) or FPLD (R482Q). (B) Schematic drawing of the human titin protein (NP_596869; 34,350 residues) showing the position of the lamin-binding fragment (prey). (C) Amino acid sequence of the lamin-binding region of human titin. The arrow indicates the first residue encoded by the smaller two-hybrid titin isolate. The larger isolate encodes a 61 kDa polypeptide termed titin 1-551. Four predicted Ig-fold domains are underlined. Non-underlined regions correspond to titin-specific regions M-is6 (residues 61-172) and M-is7 (residues 353-462).