Trypanosome ornithine decarboxylase is stable because it lacks sequences found in the carboxyl terminus of the mouse enzyme which target the latter for intracellular degradation

• Published in: The Journal of biological chemistry 1990-07, Vol.265 (20), p.11823-11826
• Main Authors: GHODA, L, PHILLIPS, M. A, BASS, K. E, WANG, C. C, COFFINO, P
• Format: Article
• Language: English
• Subjects: Amino Acid Sequence; Analytical, structural and metabolic biochemistry; Animals; Base Sequence; Biological and medical sciences; Cell Line; Chimera; Enzyme Stability; Enzymes and enzyme inhibitors; Fundamental and applied biological sciences. Psychology; Genes; Lyases; Mice; Molecular Sequence Data; Oligonucleotide Probes; Ornithine Decarboxylase - genetics; Ornithine Decarboxylase - metabolism; Sequence Homology, Nucleic Acid; Species Specificity; Transfection; Trypanosoma brucei brucei - enzymology; Trypanosoma brucei brucei - genetics
• ISSN: 0021-9258; 1083-351X
• DOI: 10.1016/S0021-9258(19)38472-8

Ornithine decarboxylase (ODC) is a key enzyme in polyamine biosynthesis. Mouse ODC is rapidly degraded in mouse cells, whereas ODC within Trypanosoma brucei, a protozoan parasite infesting cattle, is stable. We have expressed cloned ODC genes of both T. brucei and mouse in ODC-deficient Chinese hamster ovary (CHO) cells. The T. brucei enzyme is stable, whereas the mouse ODC similarly expressed in CHO cells is unstable. This shows that the observed difference in intracellular stability is a property of the ODC protein itself, rather than the cellular environment in which it is expressed. A chimeric ODC composed of the amino terminus of trypanosome and the carboxyl terminus of mouse ODC is rapidly degraded in CHO cells, suggesting that peptide sequences in the mouse ODC carboxyl terminus determine its stability.