Potential Transcriptional Elements Research Articles

Molecular cloning and functional characterization of myogenin promoter in Min pig

ABSTRACTMyogenin (MyoG) plays an important role in muscle differentiation, which can initiate the formation of the fusion of muscle cells and myofibroblasts. To investigate the transcriptional regulatory mechanism of MyoG gene in Min pig, the promoter fragment spanning from −2085 bp to +118 bp was amplified with PCR, and the potential transcriptional elements were predicted via bioinformatics analysis. Subsequently, nine promoter segments with different base pair sizes were obtained and ligated into PGL3-Basic vectors, respectively. Lastly, the functional activity of each of the aforementioned promoters was tested separately in transiently transfected C2C12 cells via a dual-luciferase assay system. The results indicated that the sequence −199 bp to −31 bp may have the basic activity of the promoter. Further analysis demonstrated that the sequence −137 bp to −101 bp was important for the basic transcriptional activity. Bioinformatics analysis showed that CdxA and MZF1 transcription factors may play an important role in the regulation of MyoG expression.

Transcript Variants, Expression, and Polymorphisms of the Pig Prosaposin Gene

Prosaposin (PASP) is a sphingolipid hydrolysis protein that plays roles in both the nervous and reproduction systems. In this study, we cloned the pig PASP gene and studied its genomic organization, polymorphism, and expression pattern. Two PASP transcripts, TV1 (HQ245644) and TV2 (HQ245646), were identified in pig. TV1 was the complete transcript that encoded 527 amino acids, whereas TV2 was 9 bp shorter due to an exon 8 deletion. The pig PASP gene spanned over 34 kb in length on chromosome 14 (SSC14), and consisted of 15 exons and 14 introns. The pig PASP gene (TV1 and TV2) expressed predominantly in the cerebellum, lymphnode, pituitary, abdominal fat, hypothalamus, and cerebrum in both females and males. PASP TV1 expressed mainly in teh cerebrum, cerebellum, hypothalamus, pituitary, heart, subcutaneous fat, and foreleg muscle, while TV2 was expressed in the liver, spleen, lung, kidney, and lymphnode. In foreleg muscle, the predominant transcript was TV2 in males and TV1 in females. Some potential transcriptional elements were predicted in 5' flanking region (~3000 bp) of the PASP gene, and they were TATA boxes, RORE, Sp1, SRY, oct-1, Cdx A, and cap. Additionally, we identified 68 single-nucleotide polymorphisms and 9 indels in the pig PASP gene, and three single-nucleotide polymorphisms (C77932320T or L15F; C77928094T or P191L; A77917401G or K522R) were nonsynonymous substitutions. These results provide useful information for future functional investigations of the pig PASP gene.

621 Cell cycle arrest and induction of apoptosis by novel Cdk inhibitor MCS-C2 is associated with deregulated ubiquitination pathway in prostate cancer cells

We have cloned and sequenced 1398 bp of the rat HFE gene promoter region. The alignment of the rat promoter HFE sequence with the HFE promoter sequence from human and mouse detected several highly conserved sequences present at orthologous or heterologous positions in the three species. Subsequent analysis of the conserved promoter sequences identified the presence of 10 novel transcription elements present in the promoter regions of the human, mouse and rat HFE genes (GATA, NF-IL6, AP1, AP2, CREB, PEA3, γ-IRE, GFI1, HNF-3β, HFH2). Different gel retardation analyses performed with rat-liver nuclear extracts have confirmed the presence of factors binding to some of these transcription elements. This represents the first data concerning the identification of potential transcriptional elements of the HFE promoter in these three species. The expression pattern of the transcription factors corresponding to the novel elements identified in the HFE promoter is consistent with the potential role of the HFE promoter in the transcription regulation and function of the HFE gene. Knowledge of the identified conserved elements in the HFE promoter from human, mouse and rat provides the basis for subsequent in-vitro or in-vivo studies leading to identification of the detailed mechanisms involved in the regulation of the iron metabolism and the design of potential future alternative therapies.

Genomic organization and promoter identification of ZNF146, a gene encoding a protein consisting solely of zinc finger domains

The ZNF146 gene (alias OZF) encodes a protein consisting solely of ten zinc finger motifs. It is amplified and overexpressed in pancreatic carcinomas. To better understand the mechanisms controlling its expression, we have isolated the human ZNF146 gene and performed an initial assessment of its promoter activity. ZNF146 encompasses 25 kb of sequence and consists of four non-coding exons located upstream of a single coding exon. The sequence of proximal 1.4 kb of ZNF146 promoter has a high GC content, is devoid of a TATA box and contains several potential transcriptional elements. This region directs high-level expression of a transfected reporter construct in human cell lines. Analysis of a series of 5′-deletion constructs indicated that the first 80 bp upstream of the potential start site of transcription carry minimal promoter activity whereas the first 550 bp are required for maximal promoter activity.