Fig. 1. Constructs of human fibroblast caldesmon (CaD) and their corresponding expressing cell lines used in this study. The C-terminal fragment (CaD39) consists of amino acids 244 to 538. Ca²⁺/CaM-binding domains are labeled as gray boxes and their amino acid sequences are listed. The italic underlined letters represent the replacement of tryptophan residues with alanine in the Ca²⁺/CaM-binding-site-defective mutant (CaD39-AB). The expression levels of various constructs relative to endogenous CHO CaD in each stable cell lines are indicated by the number of + signs in parentheses.