PARP12-mediated ADP-ribosylation contributes to breast cancer cell fate by regulating AKT activation and DNA-damage response.

Breast cancer represents the primary cause of death of women under 65 in developed countries, due to the acquisition of multiple drug resistance mechanisms. The PI3K/AKT pathway is one of the major regulating mechanisms altered during the development of endocrine resistance and inhibition of steps in this signalling pathway are adopted as a key strategy to overcome this issue. ADP-ribosylation is a post-translational modification catalysed by PARP enzymes that regulates essential cellular processes, often altered in diseases.

NCOA4 transcriptional coactivator inhibits activation of DNA replication origins.

NCOA4 is a transcriptional coactivator of nuclear hormone receptors that undergoes gene rearrangement in human cancer. By combining studies in Xenopus laevis egg extracts and mouse embryonic fibroblasts (MEFs), we show here that NCOA4 is a minichromosome maintenance 7 (MCM7)-interacting protein that is able to control DNA replication. Depletion-reconstitution experiments in Xenopus laevis egg extracts indicate that NCOA4 acts as an inhibitor of DNA replication origin activation by regulating CMG (CDC45/MCM2-7/GINS) helicase.

Native expression and purification of hormone-sensitive lipase from Psychrobacter sp. TA144 enhances protein stability and activity.

Psychrobacter, a micro-organism originally isolated from Antarctic sea water, expresses an extremely active hormone-sensitive lipase (HSL) which catalyzes the hydrolysis of fatty acid esters at very low temperature and is therefore of great potential industrial and pharmaceutical interest. An insoluble form of the entire enzyme has previously been cloned and expressed in Escherichia coli, subsequently refolded and shown to be active, whilst a shorter but completely inactive version, lacking the N-terminal 98 amino acids has been expressed in soluble form. In this study the entire enzyme has been expressed as a fully soluble protein in E.