Calpain-Catalyzed Proteolysis of Human dUTPase Specifically Removes the Nuclear Localization Signal Peptide

Calpain proteases drive intracellular signal transduction via specific proteolysis of multiple substrates upon Ca(2+)-induced activation. Recently, dUTPase, an enzyme essential to maintain genomic integrity, was identified as a physiological calpain substrate in Drosophila cells. Here we investigate the potential structural/functional significance of calpain-activated proteolysis of human dUTPase.Limited proteolysis of human dUTPase by mammalian m-calpain was investigated in the presence and absence of cognate ligands of either calpain or dUTPase. Significant proteolysis was observed only in the presence of Ca(II) ions, inducing calpain action. The presence or absence of the dUTP-analogue α,β-imido-dUTP did not show any effect on Ca(2+)-calpain-induced cleavage of human dUTPase. The catalytic rate constant of dUTPase was unaffected by calpain cleavage. Gel electrophoretic analysis showed that Ca(2+)-calpain-induced cleavage of human dUTPase resulted in several distinctly observable dUTPase fragments. Mass spectrometric identification of the calpain-cleaved fragments identified three calpain cleavage sites (between residues (4)SE(5); (7)TP(8); and (31)LS(32)). The cleavage between the (31)LS(32) peptide bond specifically removes the flexible N-terminal nuclear localization signal, indispensable for cognate localization.Results argue for a mechanism where Ca(2+)-calpain may regulate nuclear availability and degradation of dUTPase

Menopausal Status Modifies Breast Cancer Risk Associated with the Myeloperoxidase (MPO) G463A Polymorphism in Caucasian Women: A Meta-Analysis

BACKGROUND: Breast cancer susceptibility may be modulated partly through polymorphisms in oxidative enzymes, one of which is myeloperoxidase (MPO). Association of the low transcription activity variant allele A in the G463A polymorphism has been investigated for its association with breast cancer risk, considering the modifying effects of menopausal status and antioxidant intake levels of cases and controls. METHODOLOGY/PRINCIPAL FINDINGS: To obtain a more precise estimate of association using the odds ratio (OR), we performed a meta-analysis of 2,975 cases and 3,427 controls from three published articles of Caucasian populations living in the United States. Heterogeneity among studies was tested and sensitivity analysis was applied. The lower transcriptional activity AA genotype of MPO in the pre-menopausal population showed significantly reduced risk (OR 0.56-0.57, p = 0.03) in contrast to their post-menopausal counterparts which showed non-significant increased risk (OR 1.14; p = 0.34-0.36). High intake of antioxidants (OR 0.67-0.86, p = 0.04-0.05) and carotenoids (OR 0.68-0.86, p = 0.03-0.05) conferred significant protection in the women. Stratified by menopausal status, this effect was observed in pre-menopausal women especially those whose antioxidant intake was high (OR 0.42-0.69, p = 0.04). In post-menopausal women, effect of low intake elicited susceptibility (OR 1.19-1.67, p = 0.07-0.17) to breast cancer. CONCLUSIONS/SIGNIFICANCE: Based on a homogeneous Caucasian population, the MPO G463A polymorphism places post-menopausal women at risk for breast cancer, where this effect is modified by diet

Effective peer-to-peer support for young people with end-stage renal disease: a mixed methods evaluation of Camp COOL

__Abstract__ __Background__ The Camp COOL programme aims to help young Dutch people with end-stage renal disease (ESRD) develop self-management skills. Fellow patients already treated in adult care (hereafter referred to as ‘buddies’) organise the day-to-day program, run the camp, counsel the attendees, and also participate in the activities. The attendees are young people who still have to transfer to adult care. This study aimed to explore the effects of this specific form of peer-to-peer support on the self-management of young people (16–25 years) with ESRD who participated in Camp COOL (CC) (hereafter referred to as ‘participants’). __Methods__ A mixed methods research design was employed. Semi-structured interviews (n = 19) with initiators/staff, participants, and healthcare professionals were conducted. These were combined with retrospective and pre-post surveys among participants (n = 62), and observations during two camp weeks. __Results__ Self-reported effects of participants were: increased self-confidence, more disease-related knowledge, feeling capable of being more responsible and open towards others, and daring to stand up for yourself. According to participants, being a buddy or having one positively affected them. Self-efficacy of attendees and independence of buddies increased, while attendees’ sense of social inclusion decreased (measured as domains of health-related quality of life). The buddy role was a pro-active combination of being supervisor, advisor, and leader. __Conclusions__ Camp COOL allowed young people to support each other in adjusting to everyday life with ESRD. Participating in the camp positively influenced self-management in this group. Peerto- peer support through buddies was much appreciated. Support from young adults was not only beneficial for adolescent attendees, but also for young adult buddies. Paediatric nephrologists are encouraged to refer patients to CC and to facilitate such initiatives. Together with nephrologists in adult care, they could take on a role in selecting buddies