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A common cis-element in promoters of protein synthesis and cell cycle genes

100%

Wyrwicz L. S., Gaj P., Hoffmann M., Rychlewski L., Ostrowski J.

Gene promoters contain several classes of functional sequence elements (cis elements) recognized by protein agents, e.g. transcription factors and essential components of the transcription machinery. Here we describe a common DNA regulatory element (tandem TCTCGCGAGA motif) of human TATA-less promoters. A combination of bioinformatic and experimental methodology suggests that the element can be critical for expression of genes involved in enhanced protein synthesis and the G1/S transition in the cell cycle. The motif was identified in a substantial fraction of promoters of cell cycle genes, like cyclins (CCNC, CCNG1), as well as transcription regulators (TAF7, TAF13, KLF7, NCOA2), chromatin structure modulators (HDAC2, TAF6L), translation initiation factors (EIF5, EIF2S1, EIF4G2, EIF3S8, EIF4) and previously reported 18 ribosomal protein genes. Since the motif can define a subset of promoters with a distinct mechanism of activation involved in regulation of expression of about 5% of human genes, further investigation of this regulatory element is an emerging task.

Unexpected formation of [M]2+from [M+CuCl+H]2+ions under CID conditions, where M is a molecule of 3,5-bis(2,2’-bipyridin-4-ylethynyl)benzoic acid or its methyl ester

86%

Frański R., Zalas M., Gierczyk B., Cegłowski M., Schroeder G., Kozik T., Hoffmann M.

Open Chemistry

2015

vol. 13

issue 1

[M+CuCl+H]2+ ions were generated using electrospray ionization (ESI); where M is a molecule of 3,5-bis(2,2’-bipyridin-4-ylethynyl)benzoic acid or its methyl ester (1 and 2, respectively). The ions were subjected to CID-MS/MS analysis. It was found that their gas phase decomposition lead to the formation of rare di-cations [M]2+, namely [1]2+ and [2]2+ ions. The formation of [1]2+ ion from [3+H+CuCl]2+ ion in the second fragmentation, where 3 is ethyl ester of 3,5-bis(2,2-bipyridin-4-ylethynyl)benzoic acid, was also observed since in the first fragmentation step the loss of ethylene molecule from [3+H+CuCl]2+ ion took place. To the best of our knowledge, it is the first time that [M]2+ ions formation from respective metal complexes has been reported. It is also unusual that formation of [M]2+ ions is not accompanied by formation of [M]+∙ ions. Furthermore, as expected, theoretical calculation and electron ionization mass spectra show that 1 and 2 are not especially prone to form [M]2+ ions. Thus formation of [M]2+ ions under CID conditions is very surprising.

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1 Acta Biochimica Polonica

1 Open Chemistry

1 2015

1 2007

2 Hoffmann M.

1 Cegłowski M.

1 Frański R.

1 Gaj P.

1 Gierczyk B.

1 Kozik T.

1 Ostrowski J.

1 Rychlewski L.

1 Schroeder G.

1 Wyrwicz L. S.

1 Zalas M.

Search results

A common cis-element in promoters of protein synthesis and cell cycle genes

Unexpected formation of [M]2+from [M+CuCl+H]2+ions under CID conditions, where M is a molecule of 3,5-bis(2,2’-bipyridin-4-ylethynyl)benzoic acid or its methyl ester