title: Synthesis and localization of myeloperoxidase protein in transfected BHK cells.
abstract: Processing and localization of myeloperoxidase was studied in nonmyeloid cells. For this purpose BHK cells were transfected with human myeloperoxidase cDNA. In the transfected cells a protein with mol wt of 85,000 was found, which reacted with the specific anti-human myeloperoxidase antiserum. In size and in sensitivity to endo-beta-N-acetylglucosaminidase H this protein resembled the myeloperoxidase precursor synthesized in human promyelocytes. Unlike in the promyelocytes, in BHK cells the 85,000-Da protein was not converted to 60,000- and 14,000-Da polypeptides of the mature enzyme. In Percoll gradients the protein was found predominantly in the light membrane fractions. Microscopic examination revealed a conspicuous immune reaction over the endoplasmic reticulum and nuclear membranes and a moderate labeling over lysosome-like organelles. Pulse-chase experiments indicated that the protein was slowly released from the endoplasmic reticulum; after 1 day the protein was found in similar amounts in cells and in the medium. The secreted protein contained at least one endo-beta-N-acetylglucosaminidase-resistant oligosaccharide. It is suggested that normal intracellular segregation of myeloperoxidase depends on a signal or component, which is not or incompletely expressed in BHK cells.
authors.affiliation: Institut für Physiologische Chemie und Pathobiochemie, Westfälische Wilhelms-Universität Münster, Federal Republic of Germany.
authors.forename: J
authors.initials: J
authors.lastname: Cully
authors.forename: B
authors.initials: B
authors.lastname: Harrach
authors.forename: H
authors.initials: H
authors.lastname: Hauser
authors.forename: N
authors.initials: N
authors.lastname: Harth
authors.forename: H
authors.initials: H
authors.lastname: Robenek
authors.forename: S
authors.initials: S
authors.lastname: Nagata
authors.forename: A
authors.initials: A
authors.lastname: Hasilik
mesh_terms: D000818:Animals; D002460:Cell Line; D006224:Cricetinae; D006801:Humans; D007668:Kidney / Q000201:enzymology / Q000648:ultrastructure; D015473:Leukemia, Promyelocytic, Acute / Q000201:enzymology; D008970:Molecular Weight; D010455:Peptides / Q000378:metabolism; D009195:Peroxidase / Q000096:biosynthesis* / Q000302:isolation & purification; D013347:Subcellular Fractions / Q000201:enzymology / Q000648:ultrastructure; D014162:Transfection
chemical_list: D010455:Peptides; D009195:Peroxidase