Protein Kinase Akt2/PKBβ Is Involved in Blastomere Proliferation of Preimplantation Mouse Embryos

The document presents a study on the role of the protein kinase Akt2 in the proliferation of blastomeres in preimplantation mouse embryos. The study found that Akt2 is crucial for normal embryo progression through cleavage stages, as it enters the pronuclei at the late one-cell stage and remains in the nucleus during later stages, which is necessary for blastomere proliferation. This nuclear localization of Akt2 is dependent on the protein Tcl1. In contrast, Akt1 and Akt3 were found to have a limited role in embryo development. Depletion of Akt2 resulted in fewer embryos reaching subsequent developmental stages and caused the remaining blastomeres to be larger, indicating a disruption in cell division. The study also highlighted the importance of serine-473 phosphorylation in this process and suggested that Akt2's pro-mitotic role might be related to its interaction with other factors such as FoxO and the Bcl-2 family. The research was supported by Sapienza grants and Ministero della Salute Ricerca Corrente, with no conflicts of interest reported by the authors. Data supporting the findings are available upon request.