CLH-3b functional domains. Open and shaded bars are predicted intramembrane and intracellular domains, respectively. Relative size of domains is approximately to scale. The regulatory domain is a 101–amino acid splice insert unique to CLH-3b (Denton et al., 2004). Sequence of regulatory domain is shown. Green highlighting indicates location of GCK-3 binding site (Denton et al., 2005). Serines 742 and 747 are highlighted in red.