title: Proliferating cell nuclear antigen (Pcna) as a direct downstream target gene of Hoxc8.
abstract: Hoxc8 is a member of Hox family transcription factors that play crucial roles in spatiotemporal body patterning during embryogenesis. Hox proteins contain a conserved 61 amino acid homeodomain, which is responsible for recognition and binding of the proteins onto Hox-specific DNA binding motifs and regulates expression of their target genes. Previously, using proteome analysis, we identified Proliferating cell nuclear antigen (Pcna) as one of the putative target genes of Hoxc8. Here, we asked whether Hoxc8 regulates Pcna expression by directly binding to the regulatory sequence of Pcna. In mouse embryos at embryonic day 11.5, the expression pattern of Pcna was similar to that of Hoxc8 along the anteroposterior body axis. Moreover, Pcna transcript levels as well as cell proliferation rate were increased by overexpression of Hoxc8 in C3H10T1/2 mouse embryonic fibroblast cells. Characterization of 2.3kb genomic sequence upstream of Pcna coding region revealed that the upstream sequence contains several Hox core binding sequences and one Hox-Pbx binding sequence. Direct binding of Hoxc8 proteins to the Pcna regulatory sequence was verified by chromatin immunoprecipitation assay. Taken together, our data suggest that Pcna is a direct downstream target of Hoxc8.
authors.affiliation: Department of Anatomy, Embryology Laboratory, Brain Korea 21 Project for Medical Science, Yonsei University College of Medicine, Seoul 120-752, Republic of Korea.
authors.forename: Hyehyun
authors.initials: H
authors.lastname: Min
authors.forename: Ji-Yeon
authors.initials: JY
authors.lastname: Lee
authors.forename: Jinwoong
authors.initials: J
authors.lastname: Bok
authors.forename: Hyun Joo
authors.initials: HJ
authors.lastname: Chung
authors.forename: Myoung Hee
authors.initials: MH
authors.lastname: Kim
mesh_terms: D000818:Animals; D001483:Base Sequence; D002478:Cells, Cultured; D047369:Chromatin Immunoprecipitation; D047108:Embryonic Development / Q000235:genetics*; D018507:Gene Expression Regulation, Developmental; D018398:Homeodomain Proteins / Q000235:genetics / Q000378:metabolism*; D051379:Mice; D008813:Mice, Inbred ICR; D008969:Molecular Sequence Data; D018809:Proliferating Cell Nuclear Antigen / Q000235:genetics*; D014158:Transcription, Genetic
chemical_list: C489815:HOXC8 protein, human; D018398:Homeodomain Proteins; D018809:Proliferating Cell Nuclear Antigen