Figure 1

A. Talin structure. The modular structure of talin is illustrated and representative binding sites for partners of vertebrate Talin1 are indicated [1, 2, 13]. All known talins, including C. intestinalis talin, contain an N-terminal FERM domain and a C-terminal I/LWEQ module [18]. The FERM domain is a conserved element that links various proteins to the plasma membrane [38]. The I/LWEQ module is a conserved F-actin-binding element that also targets Talin1 to focal adhesions in mammalian cells [13]. We show in this report that the I/LWEQ module of C. intestinalis Talin-a also contains a focal adhesion targeting signal. VBS: vinculin binding sites of Talin1. Scale bar: 500 amino acids. B. Unrooted tree showing the phylogenetic relationships of full-length talins from the mammal Homo sapiens (Hs), the bird Gallus gallus (Gg), the pufferfish Tetraodon nigroviridis (Tn), and Ciona intestinalis (Ci). The vertebrate Talin1 and Talin2 form orthologous groups, with C. intestinalis Talin-a/b as the outgroup. The complete sequence alignment upon which this tree is based and an identity/similarity matrix for these talins are shown in Additional File 1. Human Talin1 and C. intestinalis Talin-b are 56% identical and 69.4% similar over 2541 amino acids. Scale bar: 10% sequence divergence.