Oct-4 Antibody

Background

Oct-4, also known as POU domain transcription factor, Octomer- binding transcription factor 3 and Oct-3, is expressed in human and mouse totipotent embryonic stem and germ cells. It may function in preventing these cells from differentiating. Each type of established mammalian pluripotent stem cell line (embryonal carcinoma (EC) cells, embryonic stem (ES) cells and embryonic germ (EG) cells) expresses Oct-4, which disappears rapidly when the cells differentiate. Most studies on Oct-4 have been performed on murine embryos. In human oocytes of various maturity and normally developing preimplantation/cleavage embryos, a variable Oct-4 expression pattern has been revealed, concomitant with a pure cytoplasmic localization of the protein. This variability in expression fades away during compaction, indicating embryonic Oct-4 expression; the protein appears in the nucleus, implying biological activity. Functional Oct-4 has been found in human amniotic fluid. As Oct-4 transcripts have also been found in various differentiated cells, the presence of Oct-4 transcripts or proteins may not be sufficient for identifying undifferentiated cell lines in humans. It may also be important to examine the localization of Oct-4 proteins within a cell. Oct-4 has been shown to interact with Nanog and with proteins from multiple repression complexes, including the NuRD, Sin3A and Pml complexes, possibly to control ES fate. Reactivation of Oct-4 expression is postulated to occur in differentiated cells that have undergone carcinogenesis, or tumor formation.