Structure of the LDOC1 wild-type and splice variant mRNAs, and translated proteins. (A-B) Structure of the LDOC1 and LDOC1S mRNAs. The LDOC1 gene is an intronless gene that spans 1376 bp. Open boxes represent 5′ and 3′ untranslated regions (UTR) and closed boxes represent the coding sequences (CDS); the number of nucleotides is indicated below. (C) Alignment of the amino acid sequences of wild-type LDOC1 protein and the putative splice variant protein. The wild-type mRNA encodes a protein composed of 146 amino acids. The splice variant mRNA, if translated, would yield a truncated protein of 44 amino acids that corresponds mainly to the leucine zipper region of the wild-type LDOC1. Identical residues are indicated by asterisks; the dashes indicate nucleotides that have been removed from the LDOC1S mRNA by alternative splicing. The leucine zipper domain (amino acids 5-40) in the wild-type protein, indicated by an open box, would be preserved in the splice variant.