Two short protein domains are responsible for the nuclear localization of the mouse spermine oxidase mu isoform.
In mouse, at least two catalytically active splice variants (mSMOalpha and mSMOmicro) of the flavin-containing spermine oxidase enzyme are present. We have demonstrated previously that the cytosolic mSMOalpha is the major isoform, while the mSMOmicro enzyme is present in both nuclear and cytoplasmic compartments and has an extra protein domain corresponding to the additional exon VIa. By amino acid sequence comparison and molecular modeling of mSMO proteins, we identified a second domain that is necessary for nuclear localization of the mSMOmicro splice variant. A deletion mutant enzyme of this region was constructed to demonstrate its role in protein nuclear targeting by means of transient expression in the murine neuroblastoma cell line, N18TG2.
Bianchi
Marzia
M
Dipartimento di Biologia, Università Roma Tre, Roma, Italy.
Amendola
Roberto
R
Federico
Rodolfo
R
Polticelli
Fabio
F
Mariottini
Paolo
P
D017398:Alternative Splicing; D000595:Amino Acid Sequence; D000818:Animals; D002467:Cell Nucleus; D003600:Cytosol / Q000378:metabolism; D004926:Escherichia coli / Q000235:genetics; D007527:Isoenzymes; D007700:Kinetics; D051379:Mice; D008958:Models, Molecular; D008969:Molecular Sequence Data; D009154:Mutation; D009447:Neuroblastoma / Q000201:enzymology; D019913:Nuclear Localization Signals; D000587:Oxidoreductases Acting on CH-NH Group Donors / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D017434:Protein Structure, Tertiary; D017386:Sequence Homology, Amino Acid; D014407:Tumor Cells, Cultured; D014714:Vertebrates; D000097667:Polyamine Oxidase
D007527:Isoenzymes; D019913:Nuclear Localization Signals; D000587:Oxidoreductases Acting on CH-NH Group Donors; D000097667:Polyamine Oxidase