FIGURE 1

Figure 1. CHIP structure and ubiquitination activity is conserved among human and zebrafish. (A) Seven exons in the structure of STUB1 gene correspond to the TPR, helical hairpin, and U-box domains of CHIP protein. (B) Alignment of CHIP sequence from human (H. sapiens), zebrafish (D. rerio), mouse (M. musculus), rat (R. norvegicus), chicken (G. gallus), frog (X. tropicalis), pufferfish (T. rubripes), and Japanese rice fish (O. latipes). The predicted position of secondary structures is displayed above the corresponding amino acid sequences in orange, blue, and green boxes corresponding to the TPR, helical hairpin, and U-box domains, respectively. Main residues involved in the U-box dimerization (in blue) as well as interactions via the TPR (in orange) and U-box (in green) domains are marked with background color (reported in zebrafish Chip) and/or asterisks (reported in mouse CHIP). This figure was produced by using T-Coffee (Notredame et al., 2000). (C) MBP-Chip recombinant protein was detected by Western blot analysis around 80 kDa (lane 1). Identical Hsc70- and self-ubiquitination activities were observed for human CHIP (lanes 2 and 4) and zebrafish Chip (lanes 3 and 5), shown by multiple ubiquitinated bands above MBP-CHIP (lanes 2 and 3) and Hsc70 (lanes 4 and 5).