| Embryos of the brine shrimp, Artemia franciscana , contain a novel cysteine protease composed of a cathepsin L-like catalytic subunit of 28.5 kDa, and a cell adhesion protein of the FAS-1 family of 31.5 kDa. The cathepsin L-like subunit is encoded by a cDNA derived from the CL-1 gene in A. franciscana which has been shown to be intron-less. The CL-1 gene was detected in genomic DNA prepared from nuclei of Artemia, and a second CL gene (CL-2) was obtained from a genomic library in EMBL3. Screening of Artemia adult and embryo cDNA libraries yielded sequences homologous to the CL-2 gene, and confirmed that CL-2 gene is also intron-less. Artemia adult CL-2 cDNA was found to contain two distinct open reading frames encoding the pro-peptide and mature protease. Several potential transcription factor binding sites were identified, indicating the possibility of a functional promoter in the 5' upstream sequence of the CL-2 gene. |
