Evaluation of the involvement of the human kinases NEK4 and Nek5 in the intrinsic apoptosis pathway After DNA damage

• Grant number: 19/25188-9
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date until: February 01, 2020
• End date until: September 30, 2021
• Field of knowledge: Biological Sciences - Biochemistry - Molecular Biology
• Principal Investigator: Jörg Kobarg
• Grantee: Ana Luisa Rodrigues de Oliveira
• Host Institution: Faculdade de Ciências Farmacêuticas (FCF). Universidade Estadual de Campinas (UNICAMP). Campinas , SP, Brazil
• Associated research grant: 17/03489-1 - From functional studies to searching for new inhibitors for cancer: exploring kinases that regulate the cell cycle of the human NEK family, AP.TEM

Abstract

Neks (Nima-Related Kinases) are a family of kinase proteins with important functions in cell cycle regulation, DNA damage response, and primary ciliary function. Nek4 has already been related to these three functions, but its role in these biological processes is not yet elucidated. Previous data demonstrated that Nek4 interacts with non-homologous end joining (NHEJ) proteins and that cells are more resistant to agents like etoposide in the absence of Nek4. It was also demonstrated that Nek4 expression is altered in colon cancer, and lung cancer cells depleted for Nek4 respond differently to chemotherapeutics, being more resistant to some and more sensitive to others. Studies demonstrating the involvement of Nek4 in mitochondrial regulation are being developed by our group, and they indicate an important function in mitochondrial dynamics and autophagy processes. As for Nek5, previous data indicate its involvement in muscle differentiation, through the regulation of caspase-3. Our group demonstrated that Nek5 is involved in cell death through defects in the mitochondrial respiratory chain and generation of reactive oxygen species. Moreover, bioinformatic data reinforce the theory about the involvement of Nek5 protein kinase with cancer cell dysregulations, as it is mutated in several types of cancer. Yeast two-hybrid (Y2H) screens and mass spectrometry revealed Nek4 and Nek5 interaction with BCLAF1, a transcriptional repressor that interacts with several members of the Bcl-2 family, important proteins for the intrinsic apoptosis pathway regulation. Given these, the purpose of the present study is to investigate changes in the apoptosis pathway in cell lines with altered expression of Nek4 and Nek5. Furthermore, we want to clarify whether Neks 4 and 5 play any role in mitochondrial-nucleus signaling in response to stimuli through their interaction with BCLAF1.