TY - JOUR
T1 - VRK1 phosphorylates and protects NBS1 from ubiquitination and proteasomal degradation in response to DNA damage
AU - Monsalve, Diana M.
AU - Campillo-Marcos, Ignacio
AU - Salzano, Marcella
AU - Sanz-García, Marta
AU - Cantarero, Lara
AU - Lazo, Pedro A.
N1 - Funding Information:
D.M.M, M. S-G and L. C. were supported by JAE-CSIC-Fondo Social Europeo fellowships. I. C-M. was supported by Ministerio de Economía y Competitividad-FPI-Fondo Social Europeo fellowship. This work was funded by grants from Ministerio de Economía y Competitividad ( SAF2013-44810R ; SAF2014-57791-REDC ) and Consejería de Educación de la Junta de Castilla y León ( CSI002U14 and UIC-017 ) to P.A.L.
Publisher Copyright:
© 2016 The Authors.
PY - 2016/4/1
Y1 - 2016/4/1
N2 - NBS1 is an early component in DNA-Damage Response (DDR) that participates in the initiation of the responses aiming to repair double-strand breaks caused by different mechanisms. Early steps in DDR have to react to local alterations in chromatin that are induced by DNA damage. NBS1 participates in the early detection of DNA damage and functions as a platform for the recruitment and assembly of components that are sequentially required for the repair process. In this work we have studied whether the VRK1 chromatin kinase can affect the activation of NBS1 in response to DNA damage induced by ionizing radiation. VRK1 is forming a basal preassembled complex with NBS1 in non-damaged cells. Knockdown of VRK1 resulted in the loss of NBS1 foci induced by ionizing radiation, an effect that was also detected in cell-cycle arrested cells and in ATM (-/-) cells. The phosphorylation of NBS1 in Ser343 by VRK1 is induced by either doxorubicin or IR in ATM (-/-) cells. Phosphorylated NBS1 is also complexed with VRK1. NBS1 phosphorylation by VRK1 cooperates with ATM. This phosphorylation of NBS1 by VRK1 contributes to the stability of NBS1 in ATM (-/-) cells, and the consequence of its loss can be prevented by treatment with the MG132 proteasome inhibitor of RNF8. We conclude that VRK1 regulation of NBS1 contributes to the stability of the repair complex and permits the sequential steps in DDR.
AB - NBS1 is an early component in DNA-Damage Response (DDR) that participates in the initiation of the responses aiming to repair double-strand breaks caused by different mechanisms. Early steps in DDR have to react to local alterations in chromatin that are induced by DNA damage. NBS1 participates in the early detection of DNA damage and functions as a platform for the recruitment and assembly of components that are sequentially required for the repair process. In this work we have studied whether the VRK1 chromatin kinase can affect the activation of NBS1 in response to DNA damage induced by ionizing radiation. VRK1 is forming a basal preassembled complex with NBS1 in non-damaged cells. Knockdown of VRK1 resulted in the loss of NBS1 foci induced by ionizing radiation, an effect that was also detected in cell-cycle arrested cells and in ATM (-/-) cells. The phosphorylation of NBS1 in Ser343 by VRK1 is induced by either doxorubicin or IR in ATM (-/-) cells. Phosphorylated NBS1 is also complexed with VRK1. NBS1 phosphorylation by VRK1 cooperates with ATM. This phosphorylation of NBS1 by VRK1 contributes to the stability of NBS1 in ATM (-/-) cells, and the consequence of its loss can be prevented by treatment with the MG132 proteasome inhibitor of RNF8. We conclude that VRK1 regulation of NBS1 contributes to the stability of the repair complex and permits the sequential steps in DDR.
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U2 - 10.1016/j.bbamcr.2016.02.005
DO - 10.1016/j.bbamcr.2016.02.005
M3 - Article
C2 - 26869104
AN - SCOPUS:84958580847
SN - 0167-4889
VL - 1863
SP - 760
EP - 769
JO - Biochimica et Biophysica Acta - Molecular Cell Research
JF - Biochimica et Biophysica Acta - Molecular Cell Research
IS - 4
ER -
