title: Identification and characterization of human embryonic poly(A) binding protein (EPAB).
abstract: Transcriptional silencing that begins with oocyte maturation persists during the initial mitotic divisions of the embryo. Gene expression during this period largely depends on the translational activation of maternal mRNAs by cytoplasmic polyadenylation and requires an embryonic poly(A) binding protein (EPAB). EPAB has been identified in Xenopus and mouse, where it is expressed exclusively in oocytes and early embryos until zygotic genome activation (ZGA) when it is replaced by the somatic cytoplasmic poly(A) binding protein (PABPC1). EPAB plays a central role in the regulation of maternal mRNA activation by preventing deadenylation and promoting translation. In this study, we identified and characterized the human EPAB ortholog. Human EPAB is a 619 amino acid protein with 77% identity and 84% similarity to mouse EPAB. Human EPAB mRNA is detected in ovaries, testes and several somatic tissues including pancreas, liver and thymus. Similar to the observations in Xenopus and mouse, human EPAB is the predominant poly(A) binding protein in immature (germinal vesicle) and mature (metaphase II) oocytes, and it is replaced by PABPC1 following ZGA, which occurs at 4- to 8-cell stage in human. Our findings suggest that the unique translational regulatory pathways that control gene expression during oogenesis and early embryo development may be common between model organisms and humans.
authors: Department of Obstetrics, Gynecology and Reproductive Sciences, Yale University School of Medicine, New Haven, CT 06520, USA.
authors: Ozlem
authors: O
authors: Guzeloglu-Kayisli
authors: Samuel
authors: S
authors: Pauli
authors: Habibe
authors: H
authors: Demir
authors: Maria D
authors: MD
authors: Lalioti
authors: Denny
authors: D
authors: Sakkas
authors: Emre
authors: E
authors: Seli
mesh_terms: D005260:Female; D018507:Gene Expression Regulation, Developmental / Q000235:genetics / Q000502:physiology; D006801:Humans; D008099:Liver / Q000378:metabolism; D008297:Male; D009865:Oocytes / Q000378:metabolism; D009866:Oogenesis / Q000235:genetics / Q000502:physiology; D010053:Ovary / Q000378:metabolism; D010179:Pancreas / Q000378:metabolism; D039122:Poly(A)-Binding Protein I / Q000235:genetics; D039102:Poly(A)-Binding Proteins / Q000235:genetics / Q000502:physiology*; D016133:Polymerase Chain Reaction; D013737:Testis / Q000378:metabolism; D013950:Thymus Gland / Q000378:metabolism
chemical_list: D039122:Poly(A)-Binding Protein I; D039102:Poly(A)-Binding Proteins