Overactivated Cdc42 acts through Cdc42EP3/Borg2 and NCK to trigger DNA damage response signaling and sensitize cells to DNA-damaging agents

Autor(es)

da Silva, Luiz Eduardo ; Russo, Lilian Cristina ; Forti, Fabio Luis

• Tipo de documento: Artigo Científico
• Fonte: Experimental Cell Research; v. 395, n. 2, p. 12-pg., 2020-10-15.

Resumo

The small GTPase Cdc42, a member of the Rho family, regulates essential biological processes such as cyto-skeleton remodeling, migration, vesicular trafficking and cell cycle. It was demonstrated that Cdc42 over-activation through different molecular strategies increases cell sensitivity to genotoxic stress and affects the phosphorylation status of DNA damage response proteins by unknown mechanisms. By using a combination of approaches including affinity purification/mass spectrometry (AP/MS) and colocalization microscopy analysis we were able to identify Cdc42EP3/Borg2 as a putative molecular effector of these molecular and cellular events that seem to be independent of cell line or DNA damage stimuli. We then investigated the influence of Cdc42EP3/Borg2 and other potential protein partners, such as the NCK and Septin2 proteins, which could mediate cellular responses to genotoxic stress under different backgrounds of Cdc42 activity. Clonogenic assays showed a reduced cell survival when ectopically expressing the Cdc42EP3/Borg2, NCK2 or Septin2 in an overactivated Cdc42-dependent background. Moreover, endogenous NCK appears to relocate into the nucleus upon Cdc42 overactivation, especially under genotoxic stress, and promotes the suppression of Chk1 phosphorylation. In sum, our findings reinforce Cdc42 as an important player involved in the DNA damage response acting through Cdc42EP3/Borg2 and NCK proteins following genomic instability conditions. (AU)

• Processo FAPESP: 15/03983-0 - Investigação molecular e funcional da interação de DUSP3 com proteínas nucleares: implicações em mecanismos de reparo de DNA
• Beneficiário: Fábio Luis Forti
• Modalidade de apoio: Auxílio à Pesquisa - Regular
• Processo FAPESP: 18/01753-6 - Identificação e investigação funcional de proteínas que interagem com as enzimas Cdc42 e DUSP12 em células humanas sob condições de instabilidade genômica: uma abordagem proteômica
• Beneficiário: Fábio Luis Forti
• Modalidade de apoio: Auxílio à Pesquisa - Regular