Translational regulation mediated by GCN2: modulation by the actin cytoskeleton

• Grant number: 14/17145-4
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• Start date: December 01, 2014
• End date: February 29, 2016
• Field of knowledge: Biological Sciences - Biochemistry - Molecular Biology
• Agreement: Coordination of Improvement of Higher Education Personnel (CAPES)
• Principal Investigator: Beatriz Amaral de Castilho
• Grantee: Richard Cardoso da Silva
• Host Institution: Escola Paulista de Medicina (EPM). Universidade Federal de São Paulo (UNIFESP). Campus São Paulo. São Paulo , SP, Brazil
• Associated research grant: 09/52047-5 - Translational regulation mediated by elF2 in eukaryotes, AP.TEM

Abstract

The protein kinase GCN2 down-regulates protein synthesis by phosphorylating eIF2alfa in response to different cellular stresses and starvation, while simultaneously triggering the preferential translation of some mRNAs that allows cells to promote a response to maintain their homeostasis and cope with stress. The actin cytoskeleton is an essential and dynamic structure. Its disorganization/dysregulation is connected to the emergence of serious diseases. Some studies indicate that different components of the translational machinery are physically attached to the actin cytoskeleton. Disruption of this structure in mammals leads to reduced global protein synthesis, suggesting a possible role for the actin cytoskeleton in the temporal and spatial regulation of protein synthesis. Our preliminary data suggest that the actin cytoskeleton disruption, induced by F-actin disrupting drugs, triggers the specific activation of GCN2 and the consequent phosphorylation of eIF2alfa in fibroblasts. However, the mechanisms underlying this activation are unknown. This project aims to investigate the molecular mechanism involved in the activation of GCN2 in response to the actin cytoskeleton disruption in mammals. More specifically the purposes of this project are: to find out whether the desestabilization of supra-molecular complexes containing translational machinery components is sufficient to trigger the activation of GCN2. (ii) To understand the connections between IMPACT and eEF1A with the actin cytoskeleton and their roles in the modulation of GCN2 in mammals. Altogether, the proposed approaches are relevant to pinpoint the molecular mechanisms that allow GCN2 to sense the actin cytoskeleton disruption within the cells and to promote a proper response to cope with this stress. (AU)

Scientific publications

(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)

FERRAZ, RAFAEL C.; CAMARA, HENRIQUE; DE-SOUZA, EVANDRO A.; PINTO, SILAS; PINCA, ANA PAULA F.; SILVA, RICHARD C.; SATO, VITOR N.; CASTILHO, BEATRIZ A.; MORI, MARCELO A.. IMPACT is a GCN2 inhibitor that limits lifespan in Caenorhabditis elegans. BMC Biology, v. 14, OCT 7 2016. (10/52557-0, 15/01316-7, 12/24490-4, 14/25270-3, 14/10814-8, 14/17145-4, 09/52047-5, 15/04264-8, 12/04064-0, 14/25068-0)

SILVA, RICHARD C.; CASTILHO, BEATRIZ A.; SATTLEGGER, EVELYN. A Rapid Extraction Method for mammalian cell cultures, suitable for quantitative immunoblotting analysis of proteins, including phosphorylated GCN2 and eIF2 alpha. METHODSX, v. 5, p. 75-82, 2018. (14/23889-6, 14/17145-4, 09/52047-5)

SILVA, RICHARD C.; SATTLEGGER, EVELYN; CASTILHO, BEATRIZ A.. Perturbations in actin dynamics reconfigure protein complexes that modulate GCN2 activity and promote an eIF2 response. Journal of Cell Science, v. 129, n. 24, p. 4521-4533, DEC 15 2016. (14/17145-4, 14/23889-6, 09/52047-5)