title: Nuclear actin polymerization is required for transcriptional reprogramming of Oct4 by oocytes.
abstract: Amphibian oocytes can rapidly and efficiently reprogram the transcription of transplanted somatic nuclei. To explore the factors and mechanisms involved, we focused on nuclear actin, an especially abundant component of the oocyte's nucleus (the germinal vesicle). The existence and significance of nuclear actin has long been debated. Here, we found that nuclear actin polymerization plays an essential part in the transcriptional reactivation of the pluripotency gene Oct4 (also known as Pou5f1). We also found that an actin signaling protein, Toca-1, enhances Oct4 reactivation by regulating nuclear actin polymerization. Toca-1 overexpression has an effect on the chromatin state of transplanted nuclei, including the enhanced binding of nuclear actin to gene regulatory regions. This is the first report showing that naturally stored actin in an oocyte nucleus helps transcriptional reprogramming in a polymerization-dependent manner.
authors.affiliation: Wellcome Trust, Cancer Research UK Gurdon Institute, University of Cambridge, Cambridge CB2 1QN, United Kingdom.
authors.forename: Kei
authors.initials: K
authors.lastname: Miyamoto
authors.forename: Vincent
authors.initials: V
authors.lastname: Pasque
authors.forename: Jerome
authors.initials: J
authors.lastname: Jullien
authors.forename: John B
authors.initials: JB
authors.lastname: Gurdon
mesh_terms: D000199:Actins / Q000378:metabolism*; D000818:Animals; D002352:Carrier Proteins / Q000378:metabolism; D002460:Cell Line; D002467:Cell Nucleus / Q000378:metabolism*; D065150:Cellular Reprogramming; D042002:Chromatin Assembly and Disassembly; D050556:Fatty Acid-Binding Proteins; D018507:Gene Expression Regulation, Developmental; D051379:Mice; D050814:Octamer Transcription Factor-3 / Q000235:genetics* / Q000378:metabolism*; D009865:Oocytes / Q000378:metabolism*; D058105:Polymerization; D015398:Signal Transduction; D014981:Xenopus / Q000235:genetics / Q000378:metabolism; D029867:Xenopus Proteins / Q000378:metabolism
chemical_list: D000199:Actins; D002352:Carrier Proteins; C488976:FNBP1L protein, Xenopus; D050556:Fatty Acid-Binding Proteins; D050814:Octamer Transcription Factor-3; D029867:Xenopus Proteins