FIG. 1.

The ORF 50 (K8) locus. (A) Genomic organization. Nucleotide numbering and ORF designations (open arrows) are according to the work of Russo et al.(32). The closed arrows indicate the transcriptional start site, and the vertical line indicates the polyadenylation site. (B) Pre-mRNAs from the ORF 50 (K8) locus. The lines represent introns; the open boxes represent exons. The numbers indicate the locations of splice sites. (C) Potential protein products for the alternatively spliced RNAs. The narrow open boxes represent the protein products of the RNAs. The diagonally striped box represents the leucine zipper, and the plus signs represent the basic region. The vertically striped box represents the unique region of K8. The dashed lines indicate that exon 1 can originate from the monocistronic or bicistronic transcript.