Interaction between NBS1 and the mTOR/Rictor/SIN1 complex through specific domains

PLoS One. 2013 Jun 6;8(6):e65586. doi: 10.1371/journal.pone.0065586. Print 2013.

Abstract

Nijmegen breakage syndrome (NBS) is a chromosomal-instability syndrome. The NBS gene product, NBS1 (p95 or nibrin), is a part of the Mre11-Rad50-NBS1 complex. SIN1 is a component of the mTOR/Rictor/SIN1 complex mediating the activation of Akt. Here we show that NBS1 interacted with mTOR, Rictor, and SIN1. The specific domains of mTOR, Rictor, or SIN1 interacted with the internal domain (a.a. 221-402) of NBS1. Sucrose density gradient showed that NBS1 was located in the same fractions as the mTOR/Rictor/SIN1 complex. Knockdown of NBS1 decreased the levels of phosphorylated Akt and its downstream targets. Ionizing radiation (IR) increased the NBS1 levels and activated Akt activity. These results demonstrate that NBS1 interacts with the mTOR/Rictor/SIN1 complex through the a.a. 221-402 domain and contributes to the activation of Akt activity.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adaptor Proteins, Signal Transducing / genetics
  • Adaptor Proteins, Signal Transducing / metabolism*
  • Binding Sites
  • Carrier Proteins / genetics
  • Carrier Proteins / metabolism*
  • Cell Cycle Proteins / antagonists & inhibitors
  • Cell Cycle Proteins / genetics
  • Cell Cycle Proteins / metabolism*
  • Cell Line, Tumor
  • Gamma Rays
  • Gene Expression Regulation
  • HEK293 Cells
  • Humans
  • Nuclear Proteins / antagonists & inhibitors
  • Nuclear Proteins / genetics
  • Nuclear Proteins / metabolism*
  • Phosphorylation
  • Protein Binding
  • Protein Multimerization
  • Protein Structure, Tertiary
  • Proto-Oncogene Proteins c-akt / agonists
  • Proto-Oncogene Proteins c-akt / genetics
  • Proto-Oncogene Proteins c-akt / metabolism*
  • RNA, Small Interfering / genetics
  • RNA, Small Interfering / metabolism
  • Rapamycin-Insensitive Companion of mTOR Protein
  • Signal Transduction / radiation effects*
  • TOR Serine-Threonine Kinases / genetics
  • TOR Serine-Threonine Kinases / metabolism*

Substances

  • Adaptor Proteins, Signal Transducing
  • Carrier Proteins
  • Cell Cycle Proteins
  • MAPKAP1 protein, human
  • NBN protein, human
  • Nuclear Proteins
  • RICTOR protein, human
  • RNA, Small Interfering
  • Rapamycin-Insensitive Companion of mTOR Protein
  • MTOR protein, human
  • Proto-Oncogene Proteins c-akt
  • TOR Serine-Threonine Kinases

Grants and funding

This work was supported in part to KJW by National Research Program for Genomic Medicine (NRPGM-DOH-99-TD-G-111-024, NSC100-3112-B-010-003),National Science Council Frontier grant (NSC101-2321-B-010-002), National Research Program for Biopharmaceuticals (NSC101-2325-B-010-004), a grant from Ministry of Education, Aim for the Top University Plan (101AC-T505, 102AC-TC13), center of excellence for cancer research at Taipei Veterans General Hospital (DOH101-TD-C-111-007), Taichung Veterans General Hospital (TCVGH-YM1000301, TCVGH-YM1010301), and National Health Research Institutes (NHRI-EX101-9931BI, NHRI-EX102-10230SI); and to MYC by National Science Council (NSC98-2320-B-010-023) and a grant from Ministry of Education, Aim for the Top University Plan (102AC-TC15). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.