title: Drosophila extracellular signal-regulated kinase involves the insulin-mediated proliferation of Schneider cells.
abstract: The Drosophila insulin pathway is involved in the control of the proliferation and size of the cell. The stimulation of Schneider cells with human insulin has been observed to activate Drosophila extracellular signal regulated kinase (DERK). However, the role of DERK in the regulation of proliferation is unknown. In this study, we have identified a role of DERK in the proliferation of Drosophila Schneider cells. The inhibition of DERK activity by the overexpression of DMKP-3, an ERK-specific mitogen-activated protein kinase (MAPK) phosphatase, inhibited G(1) to S phase cell cycle progression as well as bromodeoxyuridine (BrdU) incorporation, which were previously increased by human insulin. However, DMKP-3 overexpression did not significantly reduce cell size that was also enlarged by insulin treatment, which suggests the specificity of the ERK pathway in proliferation but not for cell size. G1 to S phase cell cycle progression and BrdU incorporation were also reduced by catalytically inactive DMKP-3 mutant, and they may be acquired by the trapping of DERK into cytosol. The depletion of DERK or DMKP-3 by inhibitory double-stranded RNA decreased and increased BrdU incorporation, respectively. Thus, we propose that DERK is involved in the proliferation of Schneider cells via the insulin pathway.
authors.affiliation: Department of Biotechnology, Yonsei University College of Engineering, 134 Shinchon-dong, Seodaemun-gu, Korea.
authors.forename: Hyung-Bae
authors.initials: HB
authors.lastname: Kwon
authors.forename: Sun-Hong
authors.initials: SH
authors.lastname: Kim
authors.forename: Sung-Eun
authors.initials: SE
authors.lastname: Kim
authors.forename: In-Hwan
authors.initials: IH
authors.lastname: Jang
authors.forename: Yongho
authors.initials: Y
authors.lastname: Ahn
authors.forename: Won-Jae
authors.initials: WJ
authors.lastname: Lee
authors.forename: Kang-Yell
authors.initials: KY
authors.lastname: Choi
mesh_terms: D000818:Animals; D001483:Base Sequence; D002453:Cell Cycle / Q000502:physiology; D002455:Cell Division / Q000502:physiology*; D017931:DNA Primers; D004330:Drosophila; D006801:Humans; D007328:Insulin / Q000502:physiology*; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism*
chemical_list: D017931:DNA Primers; D007328:Insulin; D020928:Mitogen-Activated Protein Kinases