DNG1, a Dictyostelium homologue of tumor suppressor ING1 regulates differentiation of Dictyostelium cells.
dng1 is a Dictyostelium homologue of the mammalian tumor suppressor ING gene. DNG1 protein localizes in the nucleus, and has a highly conserved PHD finger domain found in chromatin-remodeling proteins. Both dng1 disruption and overexpression impaired cell proliferation. In dng1-null cells, the progression of differentiation was delayed in a cell-density-dependent manner, and many tiny aggregates were formed. Exogenously applied cAMP pulses reversed the inhibitory effect caused by dng1 disruption on the aggregation during early development, but formation of tiny aggregates was not restored. dng1-overexpressing cells acquired the ability to undergo chemotaxis to cAMP earlier and exhibited enhanced differentiation. These phenotypes were found to be coupled with altered expressions of early genes such as cAMP receptor 1 (car1) and contact site A (csA). Furthermore, disordered histone modifications were demonstrated in dng1-null cells. These results suggest a regulatory role of dng1 in the transition of cells from growth to differentiation.
Department of Developmental Biology and Neurosciences, Graduate School of Life Sciences, Tohoku University, Aoba, Sendai, 980-8578, Japan. taira@biology.tohoku.ac.jp
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Mayanagi
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Amagai
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Maeda
D000595:Amino Acid Sequence; D000818:Animals; D002110:Caffeine / Q000494:pharmacology; D018797:Cell Cycle Proteins / Q000737:chemistry; D002454:Cell Differentiation; D002460:Cell Line; D049109:Cell Proliferation; D017077:Culture Media, Conditioned; D000242:Cyclic AMP / Q000494:pharmacology; D004268:DNA-Binding Proteins / Q000737:chemistry; D004023:Dictyostelium / Q000166:cytology / Q000235:genetics / Q000254:growth & development*; D018507:Gene Expression Regulation, Developmental; D016147:Genes, Tumor Suppressor; D006657:Histones / Q000378:metabolism; D008969:Molecular Sequence Data; D009154:Mutation; D014157:Transcription Factors / Q000032:analysis / Q000235:genetics / Q000502:physiology*
D018797:Cell Cycle Proteins; D017077:Culture Media, Conditioned; D004268:DNA-Binding Proteins; D006657:Histones; D014157:Transcription Factors; D002110:Caffeine; D000242:Cyclic AMP