Removal of serum factors by charcoal treatment promotes adipogenesis via a MAPK-dependent pathway

Human TSPY is a candidate oncogene and is supposed to function as a proliferation factor during spermatogenesis. It is the only mammalian protein-coding gene known to be organized as a tandem repeat gene family. It is expressed at highest level in spermatogonia and to a lower amount in primary spermatocytes. To characterize the human TSPY promoter we used the luciferase reporter system in a mouse spermatogonia derived cell line (GC-1spg) and in a GC-4spc cell line, that harbour prophase spermatocytes of the preleptotene and early pachytene stage. We isolated a 1303 bp fragment of the 5′-flanking region of exon 1 that shows significant promoter activity in GC-1spg and reduced activity in GC-4spc cells. In order to gain further insight into the organization of the TSPY-promoter, stepwise truncations of the putative promoter sequence were performed. The resulting fragments were cloned into the pGL3-vector and analysed for reporter gene activity in the murine germ cell lines GC-1spg and GC-4spc, leading to the characterization of a core promoter (−159 to −1), an enhancing region (−673 to −364) and a silencing region (−1262 to −669). Database research for cis-active elements yielded two putative SOX-like binding sites in the enhancing region and reporter gene activity was drastically reduced when three nucleotides of the AACAAT SOX core sequence were mutated. Our findings strongly suggest that testis-specific expression of human TSPY is mediated by Sox proteins. (Mol Cell Biochem 276: 159–167, 2005)     

Conservation of Position and Sequence of a Novel, Widely Expressed Gene Containing the Major Human α-Globin Regulatory Element

We have determined the cDNA and genomic structure of a gene (−14 gene) that lies adjacent to the human α-globin cluster. Although it is expressed in a wide range of cell lines and tissues, a previously described erythroid-specific regulatory element that controls expression of the α-globin genes lies within intron 5 of this gene. Analysis of the −14 gene promoter shows that it is GC rich and associated with a constitutively expressed DNase 1 hypersensitive site; unlike the α-globin promoter, it does not contain a TATA or CCAAT box. These and other differences in promoter structure may explain why the erythroid regulatory element interacts specifically with the α-globin promoters and not the −14 gene promoter, which lies between the α promoters and their regulatory element. Interspecies comparisons demonstrate that the sequence and location of the −14 gene adjacent to the α cluster have been maintained since the bird/mammal divergence, 270 million years ago.