Interplay between phosphorylation and palmitoylation mediates plasma membrane targeting and sorting of GAP43.

Phosphorylation and lipidation provide posttranslational mechanisms that contribute to the distribution of cytosolic proteins in growing nerve cells. The growth-associated protein GAP43 is susceptible to both phosphorylation and S-palmitoylation and is enriched in the tips of extending neurites. However, how phosphorylation and lipidation interplay to mediate sorting of GAP43 is unclear. Using a combination of biochemical, genetic, and imaging approaches, we show that palmitoylation is required for membrane association and that phosphorylation at Ser-41 directs palmitoylated GAP43 to the plasma membrane. Plasma membrane association decreased the diffusion constant fourfold in neuritic shafts. Sorting to the neuritic tip required palmitoylation and active transport and was increased by phosphorylation-mediated plasma membrane interaction. Vesicle tracking revealed transient association of a fraction of GAP43 with exocytic vesicles and motion at a fast axonal transport rate. Simulations confirmed that a combination of diffusion, dynamic plasma membrane interaction and active transport of a small fraction of GAP43 suffices for efficient sorting to growth cones. Our data demonstrate a complex interplay between phosphorylation and lipidation in mediating the localization of GAP43 in neuronal cells. Palmitoylation tags GAP43 for global sorting by piggybacking on exocytic vesicles, whereas phosphorylation locally regulates protein mobility and plasma membrane targeting of palmitoylated GAP43

Fluctuation des ressources et santé mentale lors d’une période de chômage

International audienc

Bullying et identité : détérioration identitaire et altération des croyances

Les agressions entre élèves en milieu scolaire constituent un problème grandissant. Le bullying peut être défini comme toutes formes de violences physiques ou mentales répétées, effectuées par un ou plusieurs individus sur une personne qui n’est pas capable de se défendre elle-même (Roland & Idsoe, 2001). Cette étude longitudinale a pour objectif d’observer le lien entre ces agressions, l’expression identitaire et les croyances fondamentales des élèves. 524 élèves âgés de 8 à 12 ans (m=9.94, SD=0.78) ont participé à l’étude. Les résultats montrent que près de 30% des élèves est victime de bullying. Par ailleurs, la fréquence des agressions semble être négativement liée à l’expression des concepts de soi et aux croyances fondamentales. Ces dimensions seraient affectées à long terme par la victimation. Ces différents résultats sont débattus à la lumière des travaux réalisés dans le domaine de la «Constructiviste Self Development Theory». - Violence among students at school is an ever-growing problem. Bullying can be defined as all forms of repeated physical or mental violence performed by an individual on another person who is not capable of defending him/herself (Roland & Idsoe, 2001). The aim of this longitudinal study is to observe the links between, the bullying on the one hand and the expression of self-concepts and fundamental assumptions on the other hand. The sample was composed of 524 pupils ages 8 to 12 (m=9.44, SD=0.78). The results show that nearly 30% of students are victims of bullying. Moreover, the frequency of attacks appears to be negatively related to the expression of self-concepts and beliefs. These dimensions are long-term, affected by victimization. These different results are discussed in the light of work in the area of «Constructivist Self Development Theory». - A violência entre os alunos na escola é um problema crescente. O bullying pode ser definido como todas as formas de violência física ou mental repetidas, realizadas por um ou mais indivíduos sobre uma pessoa incapaz de se defender a si próprio (Roland & Idsoe, 2001). Este estudo longitudinal pretende observar a relação entre estas agressões, e o auto-conceito e crenças dos alunos. A amostra foi constituída por 524 alunos com idades compreendidas entre os 8 a 12 anos (M = 9,44, DP = 0,78). Os resultados mostram que cerca de 30% dos alunos são vítimas de bullying. Além disso, a frequência de agressões parece encontrar-se negativamente relacionada à expressão do auto-conceito e crenças. Estas dimensões são afectadas a longo prazo pela vitimização. Estes diferentes resultados são discutidos à luz dos trabalhos realizados na área da «Constructivist Self Development Theory»

Adherence to oral antineoplastic agents by cancer patients: definition and literature review

International audienceSince the 1990s, oral chemotherapy has been gaining ground as cancer treatment. This therapy seems to have few toxic effects and offers patients good quality of life. However, in addition to the fears the therapy might generate in patients, oral treatment raises a new issue, which, until now, has been marginal in this field: therapeutic observance or adherence. We investigated the research into adherence to oral chemotherapy among cancer patients published between 1990 and July 2013. Studies showed considerable diversity in terms of both the definition and measurement of adherence. As well, adherence to antineoplastic therapy is affected by the patient's understanding of the treatment and ability to remember information provided by the physician, treatment length and psychological distress. Our review of the few studies on adherence to anticancer drug treatment raises some questions that could be pursued in future research. In light of our findings, patients should receive 'therapy education' to help them and their support groups better understand the disease and its treatment and to achieve optimal health management and improved treatment effectiveness