Anticorrosion film of benzimidazole on brass in ammonia
JOURNAL OF THE INDIAN CHEMICAL SOCIETY
Authors: Bag, SK; Chakraborty, SB; Chaudhuri, SR
Benzimidazole (Hbz) forms a highly stable insoluble film impeding dissolution of brass ill ammonia. It is a mixed inhibitor, inhibiting primarily by blocking the reaction centres. Rise of temperature favours corrosion, but to a much lesser extent in presence of inhibitors, because of chemisorption, leading to a net increase in inhibition efficiency. From ir and electronic spectral measurements, the anticorrosion film has been ascribed to formation of bis-benzimidazolato complexes of Cu-II and Zn-II.
HTLV-1 bZIP factor impedes the menin tumor suppressor and upregulates JunD-mediated transcription of the hTERT gene
Authors: Borowiak, Malgorzata; Kuhlmann, Anne-Sophie; Girard, Sophie; Gazzolo, Louis; Mesnard, Jean-Michel; Jalinot, Pierre; Dodon, Madeleine Duc
Telomerase activity in cancer cells is dependent on the transcriptional regulation of the human telomerase reverse transcriptase (hTERT) gene, encoding the catalytic subunit of human telomerase. We have shown previously that HTLV-1 basic leucine zipper (HBZ), a viral regulatory protein encoded by the human retrovirus, human T-cell leukemia virus, type 1 (HTLV-1) cooperates with JunD to enhance hTERT transcription in adult T-cell leukemia (ATL) cells. Menin, the product of the tumor-suppressor MEN-1 gene, also interacts with JunD, represses its transcriptional activity and downregulates telomerase expression. The main objective of this study was to examine how menin and HBZ get involved in the regulation of hTERT transcription. In this study, we report that JunD and menin form a repressor complex of hTERT transcription in HBZ-negative cells. Conversely, in HBZ-positive cells, the formation of a JunD/HBZ/menin ternary complex and the recruitment of p300 histone acetyl transferase activity by HBZ lead to a decreased activity of the JunDmenin suppressor unit that correlates with the activation of hTERT transcription. Silencing HBZ or menin expression in ATL cells confirms that these proteins are differentially involved in telomerase regulation. These results propose that HBZ, by impeding the tumor-suppressor activity of menin, functions as a leukemogenic cofactor to upregulate gene transcription and promote JunD-mediated leukemogenesis.