title: A monoclonal antibody raised against bacterially expressed MPV17 sequences shows peroxisomal, endosomal and lysosomal localisation in U2OS cells.
abstract: Recessive mutations in the MPV17 gene cause mitochondrial DNA depletion syndrome, a fatal infantile genetic liver disease in humans. Loss of function in mice leads to glomerulosclerosis and sensineural deafness accompanied with mitochondrial DNA depletion. Mutations in the yeast homolog Sym1, and in the zebra fish homolog tra cause interesting, but not obviously related phenotypes, although the human gene can complement the yeast Sym1 mutation. The MPV17 protein is a hydrophobic membrane protein of 176 amino acids and unknown function. Initially localised in murine peroxisomes, it was later reported to be a mitochondrial inner membrane protein in humans and in yeast. To resolve this contradiction we tested two new mouse monoclonal antibodies directed against the human MPV17 protein in Western blots and immunohistochemistry on human U2OS cells. One of these monoclonal antibodies showed specific reactivity to a protein of 20 kD absent in MPV17 negative mouse cells. Immunofluorescence studies revealed colocalisation with peroxisomal, endosomal and lysosomal markers, but not with mitochondria. This data reveal a novel connection between a possible peroxisomal/endosomal/lysosomal function and mitochondrial DNA depletion.
authors.affiliation: Heinrich-Pette-Institute, Leibniz-Institute for Experimental Virology, Martinistrasse 52, 20251, Hamburg, Germany. hans.weiher@fh-brs.de.|Bonn-Rhein-Sieg University, von Liebig Strasse 20, 53359, Rheinbach, Germany. hans.weiher@fh-brs.de.
authors.forename: Hans
authors.initials: H
authors.lastname: Weiher
authors.affiliation: Institute for Biomedical Aging Research, University of Innsbruck, Rennweg 10, 6020, Innsbruck, Austria. Haymo.Pircher@uibk.ac.at.
authors.forename: Haymo
authors.initials: H
authors.lastname: Pircher
authors.affiliation: Institute for Biomedical Aging Research, University of Innsbruck, Rennweg 10, 6020, Innsbruck, Austria. Pidder.Jansen-Duerr@uibk.ac.at.
authors.forename: Pidder
authors.initials: P
authors.lastname: Jansen-Dürr
authors.affiliation: Institutes of Molecular Medicine and Experimental Immunology, Universität Bonn, 53105, Bonn, Germany. silke.hegenbarth@tum.de.
authors.forename: Silke
authors.initials: S
authors.lastname: Hegenbarth
authors.affiliation: Institutes of Molecular Medicine and Experimental Immunology, Universität Bonn, 53105, Bonn, Germany. Percy.Knolle@tum.de.
authors.forename: Percy
authors.initials: P
authors.lastname: Knolle
authors.affiliation: Department of Biochemistry, Biocenter Oulu, University of Oulu, FI-90014, Oulu, Finland. silke.grunau@gmx.de.
authors.forename: Silke
authors.initials: S
authors.lastname: Grunau
authors.affiliation: Department of Biochemistry, Biocenter Oulu, University of Oulu, FI-90014, Oulu, Finland. Miia.Vapola@oulu.fi.
authors.forename: Miia
authors.initials: M
authors.lastname: Vapola
authors.affiliation: Department of Biochemistry, Biocenter Oulu, University of Oulu, FI-90014, Oulu, Finland. kalervo.hiltunen@oulu.fi.
authors.forename: J Kalervo
authors.initials: JK
authors.lastname: Hiltunen
authors.affiliation: School of Biological Sciences, University of Essex, Colchester, CO4 3SQ, UK. rzwacka@essex.ac.uk.
authors.forename: Ralf M
authors.initials: RM
authors.lastname: Zwacka
authors.affiliation: Max Planck Institute for Plant Breeding Research, Carl-von-Linné-Weg 10, 50829, Cologne, Germany. schmelektromail@web.de.
authors.forename: Elmon
authors.initials: E
authors.lastname: Schmelzer
authors.affiliation: Heinrich-Pette-Institute, Leibniz-Institute for Experimental Virology, Martinistrasse 52, 20251, Hamburg, Germany. kerstin.reumann@hpi.uni-hamburg.de.
authors.forename: Kerstin
authors.initials: K
authors.lastname: Reumann
authors.affiliation: Heinrich-Pette-Institute, Leibniz-Institute for Experimental Virology, Martinistrasse 52, 20251, Hamburg, Germany. h.will@uke.de.
authors.forename: Hans
authors.initials: H
authors.lastname: Will
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal / Q000096:biosynthesis / Q000737:chemistry* / Q000302:isolation & purification; D045744:Cell Line, Tumor; D004272:DNA, Mitochondrial / Q000235:genetics / Q000378:metabolism; D011992:Endosomes / Q000378:metabolism* / Q000648:ultrastructure; D005347:Fibroblasts / Q000378:metabolism / Q000648:ultrastructure; D005455:Fluorescent Antibody Technique; D015870:Gene Expression; D006801:Humans; D008247:Lysosomes / Q000378:metabolism* / Q000648:ultrastructure; D008565:Membrane Proteins / Q000235:genetics* / Q000378:metabolism; D051379:Mice; D008928:Mitochondria / Q000378:metabolism / Q000648:ultrastructure; D024101:Mitochondrial Proteins / Q000235:genetics* / Q000378:metabolism; D009154:Mutation; D010006:Osteoblasts / Q000378:metabolism / Q000648:ultrastructure; D020675:Peroxisomes / Q000378:metabolism* / Q000648:ultrastructure; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism
chemical_list: D000911:Antibodies, Monoclonal; D004272:DNA, Mitochondrial; C530370:MPV17 protein, human; D008565:Membrane Proteins; D024101:Mitochondrial Proteins; D011994:Recombinant Proteins