title: Dictyopyrones, novel alpha-pyronoids isolated from Dictyostelium spp., promote stalk cell differentiation in Dictyostelium discoideum.
abstract: Dictyopyrones A and B (DpnA and B), whose function(s) is not known, were isolated from fruiting bodies of Dictyostelium discoideum. In the present study, to assess their function(s), we examined the effects of Dpns on in vitro cell differentiation in D. discoideum monolayer cultures with cAMP. Dpns at 1-20 microM promoted stalk cell formation to some extent in the wild-type strain V12M2. Although Dpns by themselves could hardly induce stalk cell formation in a differentiation-inducing factor (DIF)-deficient strain HM44, both of them dose-dependently promoted DIF-1-dependent stalk cell formation in the strain. In the sporogenous strain HM18, Dpns at 1-20 microM suppressed spore formation and promoted stalk cell formation in a dose-dependent manner. Analogs of Dpns were less effective in affecting cell differentiation in both HM44 and HM18 cells, indicating that the activity of Dpns should be chemical structure specific. It was also shown that DpnA at 2-20 microM dose-dependently suppressed spore formation induced with 8-bromo cAMP and promoted stalk cell formation in V12M2 cells. Interestingly, it was shown by the use of RT-PCR that DpnA at 10 microM slightly promoted both prespore- and prestalk-specific gene expressions in an early phase of V12M2 and HM18 in vitro differentiation. The present results suggest that Dpns may have functions (1) to promote both prespore and prestalk cell differentiation in an early stage of development and (2) to suppress spore formation and promote stalk cell formation in a later stage of development in D. discoideum.
authors.affiliation: Department of Basic Sciences for Medicine, Gunma University School of Health Sciences, Maebashi 371-8514, Japan.
authors.forename: Akiko
authors.initials: A
authors.lastname: Arai
authors.forename: Yukino
authors.initials: Y
authors.lastname: Goto
authors.forename: Aiko
authors.initials: A
authors.lastname: Hasegawa
authors.forename: Kohei
authors.initials: K
authors.lastname: Hosaka
authors.forename: Haruhisa
authors.initials: H
authors.lastname: Kikuchi
authors.forename: Yoshiteru
authors.initials: Y
authors.lastname: Oshima
authors.forename: Susumu
authors.initials: S
authors.lastname: Tanaka
authors.forename: Yuzuru
authors.initials: Y
authors.lastname: Kubohara
mesh_terms: D000818:Animals; D002454:Cell Differentiation / Q000187:drug effects*; D002478:Cells, Cultured; D000242:Cyclic AMP / Q000494:pharmacology; D004023:Dictyostelium / Q000166:cytology* / Q000235:genetics / Q000254:growth & development / Q000502:physiology*; D004305:Dose-Response Relationship, Drug; D005786:Gene Expression Regulation / Q000187:drug effects; D015394:Molecular Structure; D009154:Mutation; D011753:Pyrones / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D033761:Spores, Protozoan / Q000187:drug effects / Q000235:genetics / Q000502:physiology
chemical_list: D011753:Pyrones; C507376:dictyopyrone A; C507377:dictyopyrone B; D000242:Cyclic AMP