title: Misexpression of mouse porcupine isoforms modulates the differentiation of P19 embryonic carcinoma cells.
abstract: Drosophila porcupine (porc) encodes an ER membrane protein that is required for the processing of the Drosophila Wnt family. Homologs of porc have been identified in various multicellular organisms and have been implicated in the biosynthesis of Wnt proteins. In contrast to Drosophila, vertebrates generate four different porc mRNAs (A-D) by alternative splicing. Murine porcD (MporcD) mRNA levels transiently increase during the neuroectodermal differentiation of P19 cells, but diminish during mesodermal differentiation. P19 cells constitutively expressing mouse porcA (MporcA), but not MporcD, undergo apoptosis by the induction of neuroectodermal differentiation. Meanwhile, P19 cells constitutively expressing MporcD, but not MporcA, do not adopt mesodermal cell morphology and fail to express myf-5 when induced to mesodermal differentiation. These results therefore demonstrate that the alternative splicing of Mporc is regulated in a cell-type specific manner, and the resulting Mporc isoforms have different functions in the neuroectodermal and mesodermal differentiation of P19 cells.
authors.affiliation: Graduate Program for Regulation of Biological Signals, Graduate School of Bioagricultural Science, Nagoya University, Chikusa, Nagoya 464-8601, Japan.
authors.forename: Kimiko
authors.initials: K
authors.lastname: Tanaka
authors.forename: Yasuo
authors.initials: Y
authors.lastname: Kitagawa
authors.forename: Tatsuhiko
authors.initials: T
authors.lastname: Kadowaki
mesh_terms: D000217:Acyltransferases; D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D002454:Cell Differentiation / Q000235:genetics / Q000502:physiology*; D045744:Cell Line, Tumor; D002471:Cell Transformation, Neoplastic / Q000235:genetics / Q000378:metabolism; D015972:Gene Expression Regulation, Neoplastic / Q000502:physiology*; D008565:Membrane Proteins / Q000096:biosynthesis* / Q000235:genetics; D051379:Mice; D008969:Molecular Sequence Data; D014411:Neoplastic Stem Cells / Q000378:metabolism* / Q000473:pathology*; D020033:Protein Isoforms / Q000096:biosynthesis / Q000235:genetics
chemical_list: D008565:Membrane Proteins; D020033:Protein Isoforms; D000217:Acyltransferases; C491187:Porcn protein, mouse