Misexpression of mouse porcupine isoforms modulates the differentiation of P19 embryonic carcinoma cells

Authors

  • Kimiko Tanaka,

    1. Graduate Program for Regulation of Biological Signals, Graduate School of Bioagricultural Science, Nagoya University, Chikusa, Nagoya 464-8601, Japan
    Search for more papers by this author
  • Yasuo Kitagawa,

    1. Graduate Program for Regulation of Biological Signals, Graduate School of Bioagricultural Science, Nagoya University, Chikusa, Nagoya 464-8601, Japan
    Search for more papers by this author
  • Tatsuhiko Kadowaki

    Corresponding author
    1. Graduate Program for Regulation of Biological Signals, Graduate School of Bioagricultural Science, Nagoya University, Chikusa, Nagoya 464-8601, Japan
    Search for more papers by this author

Corresponding author. Tel./fax: +81-52-789-5237 emi@nuagr1.agr.nagoya-u.ac.jp

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.

Ancillary