Fig. 9. The repeat region of XIRP2 has Xin-repeat-like properties. (A) The putative structure of XIRP2. Grey boxes indicate the 28 Xin repeats within the repeat region of the protein; their sequences and consensus sequence (italic) are given in (B). Identical amino acids at each position are shaded dark grey and conserved residues light grey. In actin-binding (C) and actin-bundling (D) assays, these repeats (arrow) are pelleted together with skeletal-muscle actin (asterisk). Upon expression in A7r5 cells, the full-length EGFP-tagged XIRP2 repeat region (E) is targeted to structures known to contain F-actin, such as stress fibres (arrows) and focal adhesions (arrowheads) that are counterstained by TRITC-phalloidin (F).