Dynamics of the interaction between Ku70NLS and Importin-alpha in the classical nuclear import pathway

• Grant number: 12/19447-2
• Support Opportunities: Scholarships in Brazil - Doctorate
• Start date: September 01, 2013
• End date: July 20, 2016
• Field of knowledge: Biological Sciences - Biophysics - Molecular Biophysics
• Principal Investigator: Ney Lemke
• Grantee: Marcos Tadeu Geraldo
• Host Institution: Instituto de Biociências (IBB). Universidade Estadual Paulista (UNESP). Campus de Botucatu. Botucatu , SP, Brazil
• Associated scholarship(s): 14/21976-9 - Interaction of Ku70NLS and Importin-alpha based on molecular dynamics with excited normal modes (MDeNM), BE.EP.DR

Abstract

The nuclear import systems are responsible for the exchange between cytoplasm and nucleus, allowing nuclear proteins to migrate through the membrane separating the two regions of the cell. An important group of proteins imported into the nucleus are proteins involved in DNA repair pathways, for example, Ku70 protein, which is involved in the repair pathway of double-stranded breaks by non-homologous end joining. The Ku70 is transported by the classical nuclear import pathway mediated by Importin-alpha and Importin-beta and binds directly to Importin-alpha through the recognition of a nuclear localization sequence (NLS). Overall, for the proteins to be imported, this NLS recognition may occur by primary and secondary sites or only in the primary site of Importin-alpha, characterizing the NLS as bipartite or monopartite, respectively. A crystallographic study showed that the Ku70NLS is monopartite, however, the structure of the residues near to the N-terminus region of the peptide was not elucidated. Interestingly, there is a study showing that these residues seem to have a fundamental role in the recognition by the Importin-alpha, but no study has evaluated in more details the interaction of these residues. Thus, this project proposes the use of techniques of molecular dynamics simulation, normal mode analysis and molecular docking for the study of the complex Ku70NLS:Importin-alpha. The main objective of this study is to assess whether Ku70NLS can interact as a classic bipartite/monopartite NLS or can interact in a non-classical pattern. Additionally, we will perform experiments of Isothermal Titration Calorimetry (ITC), which together with the computational data, we can respond whether Ku70NLS binds to Importin-alpha as a bipartite or monopartite NLS.

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)

GERALDO, MARCOS TADEU; SEKIJIMA TAKEDA, AGNES ALESSANDRA; KIMUS BRAZ, ANTONIO SERGIO; LEMKE, NEY. Bending-Twisting Motions and Main Interactions in Nucleoplasmin Nuclear Import. PLoS One, v. 11, n. 6, JUN 3 2016. (14/21976-9, 12/19447-2)

Academic Publications

(References retrieved automatically from State of São Paulo Research Institutions)

GERALDO, Marcos Tadeu. In silico characterization of the mechanisms of interaction between nuclear localization sequences and Importin-α. 2016. Doctoral Thesis - Universidade Estadual Paulista (Unesp). Instituto de Biociências. Botucatu Botucatu.