Colocalization of oxytocin and phosphorylated form of elongation factor 2 in the rat hypothalamus

Toru Fujisawa, Akiyoshi Moriwaki, Masayuki Matsushita, Kazuhito Tomizawa, Hideki Matsui

Research output: Contribution to journalArticle

Abstract

Oxytocin (OT) is one of the neuropituitary hormones and is synthesized in the neurons of the paraventricular nucleus (PVN) and supraoptic nucleus (SON). Previous studies have shown that the mRNAs encoding OT are delivered from the soma to both dendrites and axons of the neurons in the PVN and SON. However, it has not been elucidated whether a translational regulation mechanism to enable local synthesis of the hormone exists in the axons of the neurons of PVN and SON. Elongation factor 2 (EF2) is essential for polypeptide synthesis during protein translation. Moreover, phosphorylation of EF2 by EF2 kinase enhances the translation of certain mRNA species. In the present study, in order to shed light on the mechanisms involved in the translational regulation of OT synthesis, we investigated the localization of phosphorylated EF2. Phospho-EF2 was localized in the soma of the neurons in PVN and SON, and in the swellings of the median eminence where axonal tracts of the neurons in the PVN and SON exist. The phosphorylated form was also observed in the rat hypophysis. Moreover, phospho-EF2 and OT were colocalized in a part of the neurons in the PVN and SON. These results suggest that OT may be partially translated in the axons of neurons in the PVN and SON, and then secreted from the pituitary. Copyright

Original languageEnglish
Pages (from-to)161-166
Number of pages6
JournalActa medica Okayama
Volume61
Issue number3
Publication statusPublished - Jun 1 2007

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Keywords

  • Elongation factor 2
  • Local translation
  • Oxytocin
  • PVN
  • SON

ASJC Scopus subject areas

  • Biochemistry, Genetics and Molecular Biology(all)

Cite this

Fujisawa, T., Moriwaki, A., Matsushita, M., Tomizawa, K., & Matsui, H. (2007). Colocalization of oxytocin and phosphorylated form of elongation factor 2 in the rat hypothalamus. Acta medica Okayama, 61(3), 161-166.