Descripción del proyecto
Desvelar los mecanismos moleculares de la ubicuitinación
El sistema de la ubicuitina es una vía celular muy regulada e intrincada responsable de la degradación de proteínas por el proteasoma. Consiste en la unión de una pequeña proteína llamada ubicuitina a proteínas diana por enzimas ubicuitina E3 ligasa específicas. El sistema de transferencia de ubicuitina se ha revelado como una atractiva diana farmacológica para intervenir sobre proteínas específicas asociadas a enfermedades. El equipo del proyecto CsnCRL, financiado por el Consejo Europeo de Investigación, pretende dilucidar los mecanismos moleculares responsables de la regulación del proceso de ubicuitinación y, en especial, de las E3 ligasas. Los investigadores realizarán estudios estructurales y funcionales avanzados utilizando técnicas como la cristalografía de rayos X y la criomicroscopía electrónica. Además de una visión fundamental de la ubicuitinación, los resultados del proyecto ayudarán a descifrar el comportamiento de los complejos multisubunidad.
Objetivo
Specificity in the ubiquitin-proteasome system is largely conferred by ubiquitin E3 ligases (E3s). Cullin-RING ligases (CRLs), constituting ~30% of all E3s in humans, mediate the ubiquitination of ~20% of the proteins degraded by the proteasome. CRLs are divided into seven families based on their cullin constituent. Each cullin binds a RING domain protein, and a vast repertoire of adaptor/substrate receptor modules, collectively creating more than 200 distinct CRLs. All CRLs are regulated by the COP9 signalosome (CSN), an eight-protein isopeptidase that removes the covalently attached activator, NEDD8, from the cullin. Independent of NEDD8 cleavage, CSN forms protective complexes with CRLs, which prevents destructive auto-ubiquitination.
The integrity of the CSN-CRL system is crucially important for the normal cell physiology. Based on our previous work on CRL structures (Fischer, et al., Nature 2014; Fischer, et al., Cell 2011) and that of isolated CSN (Lingaraju et al., Nature 2014), We now intend to provide the underlying molecular mechanism of CRL regulation by CSN. Structural insights at atomic resolution, combined with in vitro and in vivo functional studies are designed to reveal (i) how the signalosome deneddylates and maintains the bound ligases in an inactive state, (ii) how the multiple CSN subunits bind to structurally diverse CRLs, and (iii) how CSN is itself subject to regulation by post-translational modifications or additional further factors.
The ERC funding would allow my lab to pursue an ambitious interdisciplinary approach combining X-ray crystallography, cryo-electron microscopy, biochemistry and cell biology. This is expected to provide a unique molecular understanding of CSN action. Beyond ubiquitination, insight into this >13- subunit CSN-CRL assembly will allow examining general principles of multi-subunit complex action and reveal how the numerous, often essential, subunits contribute to complex function.
Ámbito científico
- natural sciencesearth and related environmental sciencesgeologymineralogycrystallography
- natural sciencesphysical sciencesopticsmicroscopyelectron microscopy
- natural sciencesbiological sciencesgeneticsmutation
- natural sciencesbiological sciencesbiochemistrybiomoleculesproteinsenzymes
- natural sciencesbiological sciencesmolecular biologystructural biology
Programa(s)
Régimen de financiación
ERC-ADG - Advanced GrantInstitución de acogida
4058 Basel
Suiza