1: Int J Mol Med. 2005 Apr;15(4):743-7. Comparative genomics on Wnt3-Wnt9b gene cluster. Katoh M. Genetics and Cell Biology Section, National Cancer Center Research Institute, Tokyo 104-0045, Japan. mkatoh@ncc.go.jp WNT signals, transduced through Frizzled (FZD) receptors with extracellular WNT-binding domain and cytoplasmic Dishevelled-binding domain, are implicated in carcinogenesis and embryogenesis. WNT3-WNT9B (WNT14B) locus (17q21.31) and WNT3A-WNT9A (WNT14) locus (1q42.13) are paralogous regions within the human genome. Here, the rat Wnt3 and Wnt9b genes were identified and characterized by using bioinformatics. Wnt3 and Wnt9b genes at rat chromosome 10q32.1 were clustered in head-to-head manner with an interval of about 24 kb within AC105632.3 genome sequence. The rat Wnt3 gene, consisting of five exons, encoded a 355-aa protein with N-terminal signal peptide, 24 conserved Cys residues and two Asn-linked glycosylation sites. The rat Wnt9b gene, consisting of four exons, encoded a 359-aa protein with N-terminal signal peptide, 24 conserved Cys residues and one Asn-linked glycosylation site. The rat Wnt3 core promoter showed 80.5% nucleotide identity with human WNT3 core promoter, while rat Wnt9b core promoter showed 45.6% nucleotide identity with human WNT9B core promoter. MYB (c-Myb), ELK1, POU2F1 (OCT1), HNF4A (HNF-4), COMP1, NFYA (NF-Y) and NKX2-5 binding sites were conserved between rat Wnt3 and human WNT3 core promoters. The Wnt3-Wnt9b intergenic conserved region (IGCR), corresponding to nucleotide position 124747-125252 of AC105632.3 genome sequence, showed 85.6% nucleotide identity with human WNT3-WNT9B IGCR. GC content of rat Wnt3-Wnt9b IGCR was 59.5%. Wnt3-Wnt9b IGCR was predicted as regulatory element rather than gene because cDNA or EST derived from Wnt3-Wnt9b IGCR was not identified. This is the first report on the rat Wnt3 and Wnt9b genes as well as on comparative genomics on the Wnt3-Wnt9b gene cluster. PMID: 15754041 [PubMed - indexed for MEDLINE] --------------------------------------------------------------- 2: DNA Res. 1999 Feb 26;6(1):21-7. Structural organization of the human Elk1 gene and its processed pseudogene Elk2. Yamauchi T, Toko M, Suga M, Hatakeyama T, Isobe M. Department of Materials and Biosystem Engineering, Faculty of Engineering, Toyama University, Toyama-city, Japan. In the ets gene family of transcription factors, ELK1 belongs to the subfamily of Ternary Complex Factors (TCFs) which bind to the Serum Response Element (SRE) in conjunction with a dimer of Serum Response Factors (SRFs). The primary structure of the human Elk1 gene was determined by genomic cloning. The gene structure of Elk1 spans 15.2 kb and consists of seven exons and six introns. The coding sequence resides on exons 3, 4, 5, 6 and 7. Sequencing of cDNA clones isolated from human hippocampus library revealed that the second exon was often skipped by an alternative splicing event. All introns commenced with nucleotides GT at the 5' boundary and ended with nucleotides AG at the 3' boundary, in agreement with the proposed consensus sequence for intron spliced donor and acceptance sites. Sequence inspection of the 5'-flanking region revealed the absence of a 'TATA' box and the presence of putative cis-acting regulatory elements such as Sp1, GATA-1, CCAAT, and c-Myb. Moreover, the sequence analysis of Elk2 locus on 14q32.3 confirmed that Elk2 gene corresponds to a processed pseudogene of Elk1 which has been reported between alpha 1 gene (IGHA1) and pseudo gamma gene (IGHGP) of immunoglobulin heavy chain. Furthermore, the results of Southern analysis using DNAs from human-mouse hybrid cell lines carrying a part of 14q32 region revealed that there is another locus hybridizing to Elk1 cDNA on 14q32.2 --> qter region in addition to Elk2 locus between IGHA1 and IGHGP loci. PMID: 10231026 [PubMed - indexed for MEDLINE] --------------------------------------------------------------- 3: EMBO J. 1995 Oct 2;14(19):4781-93. ERF: an ETS domain protein with strong transcriptional repressor activity, can suppress ets-associated tumorigenesis and is regulated by phosphorylation during cell cycle and mitogenic stimulation. Sgouras DN, Athanasiou MA, Beal GJ Jr, Fisher RJ, Blair DG, Mavrothalassitis GJ. Laboratory of Molecular Oncology, National Cancer Institute, Frederick, MD 21702-1201, USA. ERF (ETS2 Repressor Factor) is a novel member of the ets family of genes, which was isolated by virtue of its interaction with the ets binding site (EBS) within the ETS2 promoter. The 2.7 kb ubiquitously expressed ERF mRNA encodes a 548 amino acid phosphoprotein that exhibits strong transcriptional repressor activity on promoters that contain an EBS. The localization of the DNA-binding domain of the protein at the N-terminus and th repression domain at the C-terminus is reminiscent of the organization of ELK1-like members of the ets family; however, there is no significant homology between ERF and ELK1 or any other ets member outside the DNA-binding domain. The repressor activity of ERF can antagonize the activity of other ets genes that are known transcriptional activators. Furthermore, ERF can suppress the ets-dependent transforming activity of the gag-myb-ets fusion oncogene of ME26 virus. Although ERF protein levels remain constant throughout the cell cycle, the phosphorylation level of the protein is altered as a function of the cell cycle and after mitogenic stimulation. The ERF protein is also hyperphosphorylated in cells transformed by the activated Ha-ras and v-src genes and the transcription repressor activity of ERF is decreased after co-transfection with activated Ha-ras or the kinase domain of the c-Raf-1 gene, indicating that ERF activity is probably regulated by the ras/MAPK pathway. Consistent with the in vivo phosphorylation and inactivation by ras, ERF is efficiently phosphorylated in vitro by Erk2 and cdc2/cyclin B kinases, at sites similar to those detected in vivo. Furthermore, a single mutation at position 526 results in the loss of a specific phosphopeptide both in in vivo and in vitro (by Erk2) labeling. Substitution of Thr526 for glutamic acid also decreases the repression ability of ERF. Our data suggest a model in which modulation of ERF activity is involved in the transcriptional regulation of genes activated during entry into G1 phase. Obstruction of the ERF repressor function by the transactivating members of the ets family of genes (i.e.gag-myb-ets) may be essential for the control of genes involved in cell proliferation and may also underlie their tumorigenic effects. PMID: 7588608 [PubMed - indexed for MEDLINE] ---------------------------------------------------------------