Fig. 2. Structure of the kal-1 locus and of the constructs used in this study. (A) Structure of the kal-1 locus on cosmid K03D10. Introns 1, 2, 3, 4 and 5 (not drawn to scale) are 7025, 1968, 949, 471, 888 nucleotides long, respectively. There is a putative transplicing site 3 bp upstream of the ATG. The 3' untranslated region is 211 nucleotides long. kal-1 is at one extremity of linkage group 1, near the gene unc-54 (map coordinates 22,88). The regions corresponding to the conserved protein domains are indicated. The approximate position of the gb503 deletion is indicated. (B) Reporter expression constructs and KAL proteins overexpression constructs used in this work. The kal-1 regulatory region, present in all constructs, corresponds to 4.3 kb of genomic sequences upstream and including the ATG of C. elegans kal-1. It drives expression of an E. coli lacZ gene (GB105), a gfp gene (GB102), the kal-1 cDNA, including the signal peptide (CeKAL), or the human KAL cDNA (HuKAL, see Materials and Methods). Abbreviations: SP, signal peptide; C-rich, cysteine-rich domain; WAP, WAP domain; FNIII, fibronectin type III repeat; NLS, nuclear localization signal.