The CSN3 subunit of the COP9 signalosome interacts with the HD region of Sos1 regulating stability of this GEF protein
| Autor: | Alberto Fernández-Medarde, Alicia Ballester, B. Anta, Begoña Anta, Ana Belén Cámara, María Pilar de Lucas, Eugenio Santos, José M. Rojas-Cabañeros, José Luis Oliva, Natasha Zarich |
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| Přispěvatelé: | Ministerio de Economía y Competitividad (España), European Commission, Instituto de Salud Carlos III, Asociación Española Contra el Cáncer, Junta de Castilla y León, Fundación Memoria de D. Samuel Solorzano Barruso, Junta de Castilla y León (España), Fundación Solorzano, Unión Europea. Fondo Europeo de Desarrollo Regional (FEDER/ERDF) |
| Rok vydání: | 2019 |
| Předmět: |
Cancer Research
biology Chemistry Growth factor medicine.medical_treatment Protein subunit Allosteric regulation Oncogenes lcsh:Neoplasms. Tumors. Oncology. Including cancer and carcinogens lcsh:RC254-282 Article Cell biology Pleckstrin homology domain Ubiquitin biology.protein medicine COP9 signalosome Molecular Biology SOS1 Protein HD domain Cancer |
| Zdroj: | Oncogenesis Repisalud Instituto de Salud Carlos III (ISCIII) Digital.CSIC. Repositorio Institucional del CSIC instname Oncogenesis, Vol 8, Iss 1, Pp 1-11 (2019) |
| Popis: | © The Author(s) 2018. Sos1 is an universal, widely expressed Ras guanine nucleotide-exchange factor (RasGEF) in eukaryotic cells. Its N-terminal HD motif is known to be involved in allosteric regulation of Sos1 GEF activity through intramolecular interaction with the neighboring PH domain. Here, we searched for other cellular proteins also able to interact productively with the Sos1 HD domain. Using a yeast two-hybrid system, we identified the interaction between the Sos1 HD region and CSN3, the third component of the COP9 signalosome, a conserved, multi-subunit protein complex that functions in the ubiquitin–proteasome pathway to control degradation of many cellular proteins. The interaction of CSN3 with the HD of Sos1 was confirmed in vitro by GST pull-down assays using truncated mutants and reproduced in vivo by co-immunoprecipitation with the endogenous, full-length cellular Sos1 protein. In vitro kinase assays showed that PKD, a COP9 signalosome-associated-kinase, is able to phosphorylate Sos1. The intracellular levels of Sos1 protein were clearly diminished following CSN3 or PKD knockdown. A sizable fraction of the endogenous Sos1 protein was found ubiquitinated in different mammalian cell types. A significant reduction of RasGTP formation upon growth factor stimulation was also observed in CSN3-silenced as compared with control cells. Our data suggest that the interaction of Sos1 with the COP9 signalosome and PKD plays a significant role in maintenance of cellular Sos1 protein stability and homeostasis under physiological conditions and raises the possibility of considering the CSN/PKD complex as a potential target for design of novel therapeutic drugs. J.M.R. received grant support from MINECO-FEDER (SAF2016-78852-R), ISCIII-MINECO (FIS-Intrasalud PI13/00703) and Spanish Association against Cancer (AECC). E.S. and A.F.M. were supported by grants from ISCIII-MINECO (FIS PI16/02137), JCyL (SA043U16-UIC 076) and Solorzano Foundation. E.S. and J.M.R. were also supported by ISCIII-RETIC (groups RTICC-RD12/0036/0001 and RTICC-RD12/0036/0021, respectively) and by CIBERONC (groups CB16/12/00352 and CB16/12/00273, respectively). Research co-financed by FEDER funds. |
| Databáze: | OpenAIRE |
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