The retinoblastoma (RB) protein is present at low levels in early mouse embryos and in pluripotent P19 embryonal carcinoma cells; however, the levels of RB rise dramatically in neuroectoderm formed both in embryos and in differentiating cultures of P19 cells. To investigate the effect of inactivating RB and related proteins p107 and p130, we transfected P19 cells with genes encoding mutated ver...

BACKGROUND Oxytocin (OT), synthesized in the heart, has the ability to heal injured hearts and to promote cardiomyogenesis from stem cells. Recently, we reported that the OT-GKR molecule, a processing intermediate of OT, potently increased the spontaneous formation of cardiomyocytes (CM) in embryonic stem D3 cells and augmented glucose uptake in newborn rat CM above the level stimulated by OT. ...

The tumor suppressor p19 (p14 in humans), encoded by the Ink4a/Arf locus, is mutated, deleted, or silenced in many forms of cancer. p19 induces growth arrest by antagonizing the activity of the p53negative regulator, Mdm2, thereby inducing a p53 transcriptional response. p19 can also inhibit cell cycle progression of mouse embryo fibroblasts lacking Cip1 or lacking both Mdm2 and p53, although i...

The p19(INK4d) protein consists of five ankyrin repeats (ANK) and controls the human cell cycle by inhibiting the cyclin D-dependent kinases (CDK) 4 and 6. We investigated the folding of p19(INK4d) by urea-induced unfolding transitions, kinetic analyses of unfolding and refolding, including double-mixing experiments and a special assay for folding intermediates. Folding is a sequential two-step...

GATA-4 is a cardiac-specific member of the GATA family of zinc finger transcription factors. During embryogenesis, GATA-4 expression is detected very early in the cardiogenic area and persists later in the developing heart. Studies have shown that GATA-4 is a potent transcriptional activator of several cardiac muscle-specific genes and a key regulator of the cardiomyocyte gene program. Consiste...

Background: The capability of embryonic carcinoma cells P19 in differentiation to Cardiomyocyte was examined through inducing effects of Oxytocin (OT) and 5-Azacytidin (5Az) individually and compared with each other in laboratory condition. Materials and Methods: P19 Embryoid Bodies (EBs) was formed through hanging drops method. Then, EBs were treated with (5Az) or (OT) and the EB medium (Ct...

Scaffold attachment factor B1 (SAFB1) is a multifunctional protein, which has previously been implicated in breast cancer. Here, we show that genetic deletion of SAFB1 in mouse embryonic fibroblasts (MEF) leads to spontaneous immortalization and altered expression of two proteins involved in immortalization and escape from senescence: low levels of p19 and high levels of TBX2. Inactivation of T...