title: Human PAPS synthase isoforms are dynamically regulated enzymes with access to nucleus and cytoplasm.
abstract: In higher eukaryotes, PAPS synthases are the only enzymes producing the essential sulphate-donor 3'-phospho-adenosine-5'-phosphosulphate (PAPS). Recently, PAPS synthases have been associated with several genetic diseases and retroviral infection. To improve our understanding of their pathobiological functions, we analysed the intracellular localisation of the two human PAPS synthases, PAPSS1 and PAPSS2. For both enzymes, we observed pronounced heterogeneity in their subcellular localisation. PAPSS1 was predominantly nuclear, whereas PAPSS2 localised mainly within the cytoplasm. Treatment with the nuclear export inhibitor leptomycin B had little effect on their localisation. However, a mutagenesis screen revealed an Arg-Arg motif at the kinase interface exhibiting export activity. Notably, both isoforms contain a conserved N-terminal basic Lys-Lys-Xaa-Lys motif indispensable for their nuclear localisation. This nuclear localisation signal was more efficient in PAPSS1 than in PAPSS2. The activities of the identified localisation signals were confirmed by microinjection studies. Collectively, we describe unusual localisation signals of both PAPS synthase isoforms, mobile enzymes capable of executing their function in the cytoplasm as well as in the nucleus.
authors.affiliation: Department of Molecular Biology II, Faculty of Biology, Centre for Medical Biotechnology, University of Duisburg-Essen, Essen, Germany.
authors.forename: Elisabeth
authors.initials: E
authors.lastname: Schröder
authors.forename: Lena
authors.initials: L
authors.lastname: Gebel
authors.forename: Andrey A
authors.initials: AA
authors.lastname: Eremeev
authors.forename: Jessica
authors.initials: J
authors.lastname: Morgner
authors.forename: Daniel
authors.initials: D
authors.lastname: Grum
authors.forename: Shirley K
authors.initials: SK
authors.lastname: Knauer
authors.forename: Peter
authors.initials: P
authors.lastname: Bayer
authors.forename: Jonathan W
authors.initials: JW
authors.lastname: Mueller
mesh_terms: D021581:Active Transport, Cell Nucleus / Q000187:drug effects; D020816:Amino Acid Motifs; D000595:Amino Acid Sequence; D000818:Animals; D002467:Cell Nucleus / Q000187:drug effects / Q000201:enzymology*; D017124:Conserved Sequence / Q000235:genetics; D003600:Cytosol / Q000201:enzymology; D005231:Fatty Acids, Unsaturated / Q000494:pharmacology; D049452:Green Fluorescent Proteins / Q000378:metabolism; D006367:HeLa Cells; D006801:Humans; D007527:Isoenzymes / Q000737:chemistry / Q000378:metabolism; D028884:Karyopherins / Q000378:metabolism; D051379:Mice; D008969:Molecular Sequence Data; D008970:Molecular Weight; D009097:Multienzyme Complexes / Q000737:chemistry / Q000378:metabolism*; D016296:Mutagenesis / Q000187:drug effects; D050505:Mutant Proteins / Q000737:chemistry / Q000378:metabolism; D009154:Mutation / Q000235:genetics; D049790:Nuclear Export Signals / Q000187:drug effects; D019913:Nuclear Localization Signals / Q000737:chemistry; D021381:Protein Transport / Q000187:drug effects; D018160:Receptors, Cytoplasmic and Nuclear / Q000378:metabolism; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D013347:Subcellular Fractions / Q000187:drug effects / Q000201:enzymology; D013430:Sulfate Adenylyltransferase / Q000737:chemistry / Q000378:metabolism*; D000097606:Exportin 1 Protein
chemical_list: D005231:Fatty Acids, Unsaturated; D049452:Green Fluorescent Proteins; D007527:Isoenzymes; D028884:Karyopherins; D009097:Multienzyme Complexes; D050505:Mutant Proteins; D049790:Nuclear Export Signals; D019913:Nuclear Localization Signals; D018160:Receptors, Cytoplasmic and Nuclear; D011993:Recombinant Fusion Proteins; D013430:Sulfate Adenylyltransferase; D000097606:Exportin 1 Protein; C485184:enhanced green fluorescent protein; C022322:PAPS synthetase; C038753:leptomycin B