Nek5 interacts with mitochondrial proteins and interferes negatively in mitochondrial mediated cell death and respiration

Author(s)

Melo Hanchuk, Talita D. ^{[1, 2]} ; Papa, Priscila Ferreira ^{[3, 2]} ; La Guardia, Paolo G. ^[4] ; Vercesi, Anibal E. ^[4] ; Kobarg, Joerg ^{[5, 1, 3, 6]}

Affiliation

^[1] Univ Estadual Campinas, Inst Biol, Programa Posgrad Biol Func & Mol, BR-13083862 Campinas, SP - Brazil

^[2] Ctr Nacl Pesquisa Energia & Mat, Lab Nacl Biociencias, Sao Paulo - Brazil

^[3] Univ Estadual Campinas, Inst Biol, Programa Posgrad Genet & Biol Mol, BR-13083862 Campinas, SP - Brazil

^[4] Dept Patol Clin, Campinas, SP - Brazil

^[5] Univ Estadual Campinas, Inst Biol, Dept Bioquim & Biol Tecidual, BR-13083862 Campinas, SP - Brazil

^[6] Univ Estadual Campinas, Fac Ciencias Farmaceut, BR-13083862 Campinas, SP - Brazil

• Document type: Journal article
• Source: CELLULAR SIGNALLING; v. 27, n. 6, p. 1168-1177, JUN 2015.
• Web of Science Citations: 8

Abstract

Mitochondria are involved in energy supply, signaling, cell death and cellular differentiation and have been implicated in several human diseases. Neks (NIMA-related kinases) represent a family of mammal protein kinases that play essential roles in cell-cycle progression, but other functions have recently been related. A yeast two-hybrid (Y2H) screen was performed to identify and characterize Nek5 interaction partners and the mitochondrial proteins Cox11, MTX-2 and BCLAF1 were retrieved. Apoptosis assay showed protective effects of stable hNek5 expression from Hek293-T's cell death after thapsigargin treatment (2 mu M). Nek5 silenced cells as well as cells expressing a ``kinase dead{''} version of Nek5, displayed an increase in ROS formation after 4 h of thapsigargin treatment. Mitochondrial respiratory chain activity was found decreased upon stable hNek5expression. Cells silenced for hNek5 on the other hand presented 1.7 fold increased basal rates of respiration, especially at the electrons transfer steps from TMPD to cytochrome c and at the complex II. In conclusion, our data suggest for the first time mitochondrial localization and functions for Nek5 and its participation in cell death and cell respiration regulation. Stable expression of hNek5 in Hek293T cells resulted in enhanced cell viability, decreased cell death and drug resistance, while depletion of hNek5by shRNA overcame cancer cell drug resistance and induced apoptosis in vitro. Stable expression of hNek5 also inhibits thapsigargin promoted apoptosis and the respiratory chain complex IV in HEK293T cells. (C) 2015 Elsevier Inc. All rights reserved. (AU)

• FAPESP's process: 10/51730-0 - Functional and structural studies of protein kinases involved in cancer and neglected diseases: towards the development of new inhibitors
• Grantee: Jörg Kobarg
• Support Opportunities: Regular Research Grants
• FAPESP's process: 10/16831-0 - Functional Characterization: The human kinase Nek5 interferes negatively in cell death and the polyglutamylation process
• Grantee: Talita Diniz Melo Hanchuk
• Support Opportunities: Scholarships in Brazil - Doctorate