CORTACTINNMQ · Cortactin signalling and actin dynamics control in cell migration and bacterial invasion
6РП — Действия „Мария Кюри“
- Период
- 2006-01-01 → 2007-12-31
- Финансиране от ЕС
- 80 000 €
- Участници
- 1
- Схема
- IRG
Линиите свързват координатора с партньорите.
Накратко на български
Протеинът кортактин и неговата роля при навлизането на бактерии като EPEC и Shigella в човешките клетки се анализират чрез промяна на клетъчните структури. Разбирането на тези механизми помага да се разкрият разликите в начина, по който различните бактерии заразяват организма.
Кратко обяснение, генерирано от езиков модел по текста на CORDIS. Оригиналът е по-долу.
Резултати накратко
Final Activity Report Summary - CORTACTINNMQ (Cortactin signalling and actin dynamics control in cell migration and bacterial invasion)
We have studied the role of cortactin function in pedestal formation by EPEC. As recently described Cortactin siRNA treated cells had reduced capability to support pedestal formation by EPEC. Moreover mutations of both the SH3 and NTA domain of cortactin interfere with pedestal formation. overexpression of an Erk-phosphorylated cortactin mimicking mutant exerted a neutral effect comparable to wt cortactin; whereas a Src-phosphorylated cortactin mimicking mutant blocked pedestal formation. However, a non-previously used erk non-phosphorylable mutant blocked pedestal formation similarly to the src non-phosphorylable mutant, which implicates, opposing the current view, that both phosphorylations exert a role on pedestal formation. On other hand, cortactin and crk were shown to sinergise on actin polymerization during the invasion of Shigella, and that effect was dependent on the tyrosine phosphorylation of cortactin. We analysed if similar model could apply to EPEC infection. Using siRNAi and overexpression of a dominant negative mutant of crk, we demonstrated that Crk is not required for pedestal formation by EPEC. This result establishes a major signal transduction difference between Shigella and EPEC infection models. We used purified recombinant cortactin and tir proteins to demonstrate a direct interaction of both and to characterise the effect of this interaction on actin polymerisation in vitro. Using nck and n-wasp K.O. cells we further analysed what type of complexes are de facto formed in vivo.
Текст от CORDIS, на английски · Данни: CORDIS, © Европейски съюз
Цел на проекта
Actin-based motility underlies multiple cellular processes. Polymerisation of actin from the monomeric to the filamentous form is mediated by the Arp2/3 complex. This complex has to be activated to be functional. To date there are two families of proteins that directly bind and activate the Arp2/3 complex through a conserved DDW motif: Wiskott-Aldrich syndrome proteins and cortactin. Initially there was not functional relationship between them until we demonstrated that cortactin binds and activates N-WASP via its SH3 domain. Thus cortactin can activate actin synthesis directly through its N-terminal DDW motif, or indirectly by binding to N-WASP via its c-terminal SH3 domain. Furthermore we demonstrated that cortactin activation of N-WASP is positive/negatively regulated by erk/src phosphorylation of cortactin respectively, probably by regulating the accessibility of its SH3 domain.Based on these in vitro experiments, we proposed a switch on/off mechanism, which could be an important control mechanism of acti n remodelling. Thus cortactin has emerged as a multidomain protein that acts as a scaffold that redistributes signals to promote Arp2/3 complex mediated actin synthesis in a variety of cellular processes. The major objective of the project is the validation of the model in vivo.The questions we will try to address are:1) Cortactin is considered an oncogene. How is the activation state of cortactin contributing to its oncogenic potential?2) Cortactin redistributes from the cytoplasm to the cortical cytoskeleton. How is the switch affecting its localization? Are there differences in the final actin structure formed? Is it regulating cortactin binding pattern?3) Cortactin is implicated in pedestal formation by EPEC. Is the switch implicated in pedestal formation or in the underlying diarrhoea? The relevance of translating this model to in vivo settings has already being discussed enthusiastically by the scientist community.
Оригинален текст от CORDIS (на английски).
Участници
- UNIVERSIDAD COMPLUTENSE DE MADRID · MADRIDКоординаторИспания
Връзки
Данни: CORDIS, © Европейски съюз