title: PKC-Mediated ZYG1 Phosphorylation Induces Fusion of Myoblasts as well as of Dictyostelium Cells.
abstract: We have previously demonstrated that a novel protein ZYG1 induces sexual cell fusion (zygote formation) of Dictyostelium cells. In the process of cell fusion, involvements of signal transduction pathways via Ca(2+) and PKC (protein kinase C) have been suggested because zygote formation is greatly enhanced by PKC activators. In fact, there are several deduced sites phosphorylated by PKC in ZYG1 protein. Thereupon, we designed the present work to examine whether or not ZYG1 is actually phosphorylated by PKC and localized at the regions of cell-cell contacts where cell fusion occurs. These were ascertained, suggesting that ZYG1 might be the target protein for PKC. A humanized version of zyg1 cDNA (mzyg1) was introduced into myoblasts to know if ZYG1 is also effective in cell fusion of myoblasts. Quite interestingly, enforced expression of ZYG1 in myoblasts was found to induce markedly their cell fusion, thus strongly suggesting the existence of a common signaling pathway for cell fusion beyond the difference of species.
authors.affiliation: Graduate School of Life Sciences, Tohoku University, Sendai 980-8577, Japan.
authors.forename: Aiko
authors.initials: A
authors.lastname: Amagai
authors.forename: Harry
authors.initials: H
authors.lastname: Macwilliams
authors.forename: Takahiro
authors.initials: T
authors.lastname: Isono
authors.forename: Mariko
authors.initials: M
authors.lastname: Omatsu-Kanbe
authors.forename: Shinya
authors.initials: S
authors.lastname: Urano
authors.forename: Kazuo
authors.initials: K
authors.lastname: Yamamoto
authors.forename: Yasuo
authors.initials: Y
authors.lastname: Maeda