title: Fly versus man: evolutionary impairment of nucleolar targeting affects the degradome of Drosophila's Taspase1.
abstract: Human Taspase1 is essential for development and cancer by processing critical regulators, such as the mixed-lineage leukemia protein. Likewise, its ortholog, trithorax, is cleaved by Drosophila Taspase1 (dTaspase1), implementing a functional coevolution. To uncover novel mechanism regulating protease function, we performed a functional analysis of dTaspase1 and its comparison to the human ortholog. dTaspase1 contains an essential nucleophile threonine(195), catalyzing cis cleavage into its α- and β-subunits. A cell-based assay combined with alanine scanning mutagenesis demonstrated that the target cleavage motif for dTaspase1 (Q(3)[F/I/L/M](2)D(1)↓G(1')X(2')X(3')) differs significantly from the human ortholog (Q(3)[F,I,L,V](2)D(1)↓G(1')x(2')D(3')D(4')), predicting an enlarged degradome containing 70 substrates for Drosophila. In contrast to human Taspase1, dTaspase1 shows no discrete localization to the nucleus/nucleolus due to the lack of the importin-α/nucleophosmin1 interaction domain (NoLS) conserved in all vertebrates. Consequently, dTaspase1 interacts with neither the Drosophila nucleoplasmin-like protein nor human nucleophosmin1. The impact of localization on the protease's degradome was confirmed by demonstrating that dTaspase1 did not efficiently process nuclear substrates, such as upstream stimulatory factor 2. However, genetic introduction of the NoLS into dTaspase1 restored its nucleolar localization, nucleophosmin1 interaction, and efficient cleavage of nuclear substrates. We report that evolutionary functional divergence separating vertebrates from invertebrates can be achieved for proteases by a transport/localization-regulated mechanism.
authors: *Molecular and Cellular Oncology, Ear, Nose and Throat Department, University Medical Center of Mainz, Mainz, Germany; Institute for Molecular Biology, Centre for Medical Biotechnology, Mainz Scientific Screening Center UG & Co. KG, University of Duisburg-Essen, Essen, Germany; Max Planck Institute of Immunobiology and Epigenetics, Freiburg, Germany; Cell and Matrix Biology, Institute for Zoology, and Institute for Pharmacy and Biochemistry, University of Mainz, Mainz, Germany; II. Medizinische Klinik, Technische Universität München, Munich, Germany; and Department of Toxicology, University Medical Center, Mainz, Germany wuensch@uni-mainz.de rstauber@uni-mainz.de.
authors: Désirée
authors: D
authors: Wünsch
authors: *Molecular and Cellular Oncology, Ear, Nose and Throat Department, University Medical Center of Mainz, Mainz, Germany; Institute for Molecular Biology, Centre for Medical Biotechnology, Mainz Scientific Screening Center UG & Co. KG, University of Duisburg-Essen, Essen, Germany; Max Planck Institute of Immunobiology and Epigenetics, Freiburg, Germany; Cell and Matrix Biology, Institute for Zoology, and Institute for Pharmacy and Biochemistry, University of Mainz, Mainz, Germany; II. Medizinische Klinik, Technische Universität München, Munich, Germany; and Department of Toxicology, University Medical Center, Mainz, Germany.
authors: Angelina
authors: A
authors: Hahlbrock
authors: *Molecular and Cellular Oncology, Ear, Nose and Throat Department, University Medical Center of Mainz, Mainz, Germany; Institute for Molecular Biology, Centre for Medical Biotechnology, Mainz Scientific Screening Center UG & Co. KG, University of Duisburg-Essen, Essen, Germany; Max Planck Institute of Immunobiology and Epigenetics, Freiburg, Germany; Cell and Matrix Biology, Institute for Zoology, and Institute for Pharmacy and Biochemistry, University of Mainz, Mainz, Germany; II. Medizinische Klinik, Technische Universität München, Munich, Germany; and Department of Toxicology, University Medical Center, Mainz, Germany.
authors: Christina
authors: C
authors: Heiselmayer
authors: *Molecular and Cellular Oncology, Ear, Nose and Throat Department, University Medical Center of Mainz, Mainz, Germany; Institute for Molecular Biology, Centre for Medical Biotechnology, Mainz Scientific Screening Center UG & Co. KG, University of Duisburg-Essen, Essen, Germany; Max Planck Institute of Immunobiology and Epigenetics, Freiburg, Germany; Cell and Matrix Biology, Institute for Zoology, and Institute for Pharmacy and Biochemistry, University of Mainz, Mainz, Germany; II. Medizinische Klinik, Technische Universität München, Munich, Germany; and Department of Toxicology, University Medical Center, Mainz, Germany.
authors: Sandra
authors: S
authors: Bäcker
authors: *Molecular and Cellular Oncology, Ear, Nose and Throat Department, University Medical Center of Mainz, Mainz, Germany; Institute for Molecular Biology, Centre for Medical Biotechnology, Mainz Scientific Screening Center UG & Co. KG, University of Duisburg-Essen, Essen, Germany; Max Planck Institute of Immunobiology and Epigenetics, Freiburg, Germany; Cell and Matrix Biology, Institute for Zoology, and Institute for Pharmacy and Biochemistry, University of Mainz, Mainz, Germany; II. Medizinische Klinik, Technische Universität München, Munich, Germany; and Department of Toxicology, University Medical Center, Mainz, Germany.
authors: Patrick
authors: P
authors: Heun
authors: *Molecular and Cellular Oncology, Ear, Nose and Throat Department, University Medical Center of Mainz, Mainz, Germany; Institute for Molecular Biology, Centre for Medical Biotechnology, Mainz Scientific Screening Center UG & Co. KG, University of Duisburg-Essen, Essen, Germany; Max Planck Institute of Immunobiology and Epigenetics, Freiburg, Germany; Cell and Matrix Biology, Institute for Zoology, and Institute for Pharmacy and Biochemistry, University of Mainz, Mainz, Germany; II. Medizinische Klinik, Technische Universität München, Munich, Germany; and Department of Toxicology, University Medical Center, Mainz, Germany.
authors: Dorothee
authors: D
authors: Goesswein
authors: *Molecular and Cellular Oncology, Ear, Nose and Throat Department, University Medical Center of Mainz, Mainz, Germany; Institute for Molecular Biology, Centre for Medical Biotechnology, Mainz Scientific Screening Center UG & Co. KG, University of Duisburg-Essen, Essen, Germany; Max Planck Institute of Immunobiology and Epigenetics, Freiburg, Germany; Cell and Matrix Biology, Institute for Zoology, and Institute for Pharmacy and Biochemistry, University of Mainz, Mainz, Germany; II. Medizinische Klinik, Technische Universität München, Munich, Germany; and Department of Toxicology, University Medical Center, Mainz, Germany.
authors: Walter
authors: W
authors: Stöcker
authors: *Molecular and Cellular Oncology, Ear, Nose and Throat Department, University Medical Center of Mainz, Mainz, Germany; Institute for Molecular Biology, Centre for Medical Biotechnology, Mainz Scientific Screening Center UG & Co. KG, University of Duisburg-Essen, Essen, Germany; Max Planck Institute of Immunobiology and Epigenetics, Freiburg, Germany; Cell and Matrix Biology, Institute for Zoology, and Institute for Pharmacy and Biochemistry, University of Mainz, Mainz, Germany; II. Medizinische Klinik, Technische Universität München, Munich, Germany; and Department of Toxicology, University Medical Center, Mainz, Germany.
authors: Tanja
authors: T
authors: Schirmeister
authors: *Molecular and Cellular Oncology, Ear, Nose and Throat Department, University Medical Center of Mainz, Mainz, Germany; Institute for Molecular Biology, Centre for Medical Biotechnology, Mainz Scientific Screening Center UG & Co. KG, University of Duisburg-Essen, Essen, Germany; Max Planck Institute of Immunobiology and Epigenetics, Freiburg, Germany; Cell and Matrix Biology, Institute for Zoology, and Institute for Pharmacy and Biochemistry, University of Mainz, Mainz, Germany; II. Medizinische Klinik, Technische Universität München, Munich, Germany; and Department of Toxicology, University Medical Center, Mainz, Germany.
authors: Günter
authors: G
authors: Schneider
authors: *Molecular and Cellular Oncology, Ear, Nose and Throat Department, University Medical Center of Mainz, Mainz, Germany; Institute for Molecular Biology, Centre for Medical Biotechnology, Mainz Scientific Screening Center UG & Co. KG, University of Duisburg-Essen, Essen, Germany; Max Planck Institute of Immunobiology and Epigenetics, Freiburg, Germany; Cell and Matrix Biology, Institute for Zoology, and Institute for Pharmacy and Biochemistry, University of Mainz, Mainz, Germany; II. Medizinische Klinik, Technische Universität München, Munich, Germany; and Department of Toxicology, University Medical Center, Mainz, Germany.
authors: Oliver H
authors: OH
authors: Krämer
authors: *Molecular and Cellular Oncology, Ear, Nose and Throat Department, University Medical Center of Mainz, Mainz, Germany; Institute for Molecular Biology, Centre for Medical Biotechnology, Mainz Scientific Screening Center UG & Co. KG, University of Duisburg-Essen, Essen, Germany; Max Planck Institute of Immunobiology and Epigenetics, Freiburg, Germany; Cell and Matrix Biology, Institute for Zoology, and Institute for Pharmacy and Biochemistry, University of Mainz, Mainz, Germany; II. Medizinische Klinik, Technische Universität München, Munich, Germany; and Department of Toxicology, University Medical Center, Mainz, Germany.
authors: Shirley K
authors: SK
authors: Knauer
authors: *Molecular and Cellular Oncology, Ear, Nose and Throat Department, University Medical Center of Mainz, Mainz, Germany; Institute for Molecular Biology, Centre for Medical Biotechnology, Mainz Scientific Screening Center UG & Co. KG, University of Duisburg-Essen, Essen, Germany; Max Planck Institute of Immunobiology and Epigenetics, Freiburg, Germany; Cell and Matrix Biology, Institute for Zoology, and Institute for Pharmacy and Biochemistry, University of Mainz, Mainz, Germany; II. Medizinische Klinik, Technische Universität München, Munich, Germany; and Department of Toxicology, University Medical Center, Mainz, Germany wuensch@uni-mainz.de rstauber@uni-mainz.de.
authors: Roland H
authors: RH
authors: Stauber
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D005075:Biological Evolution; D015153:Blotting, Western; D002466:Cell Nucleolus / Q000378:metabolism*; D002467:Cell Nucleus / Q000378:metabolism*; D002478:Cells, Cultured; D004330:Drosophila / Q000254:growth & development / Q000378:metabolism*; D029721:Drosophila Proteins / Q000378:metabolism*; D010450:Endopeptidases / Q000378:metabolism*; D005455:Fluorescent Antibody Technique; D006801:Humans; D047468:Immunoprecipitation; D008297:Male; D018613:Microscopy, Confocal; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D010447:Peptide Hydrolases / Q000378:metabolism*; D010802:Phylogeny; D021381:Protein Transport; D059748:Proteolysis; D017386:Sequence Homology, Amino Acid; D015398:Signal Transduction
chemical_list: D029721:Drosophila Proteins; D010450:Endopeptidases; D010447:Peptide Hydrolases; C526349:taspase1, Drosophila; C480823:taspase1, human
keywords: cancer; development; leukemia; protease; threonine aspartase