Fig. 1. Structure and potential caspase cleavage sites in TIAM1. A, domain structure of murine TIAM1 (1591 amino acids). PH, PH domain; DH, DH domain. Arrowheads indicate the positions of potential caspase sites A-D; numbers indicate the aspartate residue after which the caspase would cleave. The C1199 construct, which expresses the COOH-terminal 1199 amino acids of TIAM1, was used in subsequent experiments. B, consensus caspase motifs within TIAM1 and known caspase substrates. Three types of caspase recognition motifs have been described; sites A-D in TIAM1 fall into the three groups as indicated.