Nuclear localization of human MEIOB requires its NLS in the OB domain and interaction with SPATA22

Acta Biochim Biophys Sin (Shanghai). 2022 Nov 25;55(1):154-161. doi: 10.3724/abbs.2022156.

Abstract

MEIOB is a vital protein in meiotic homologous recombination and plays an indispensable role in human gametogenesis. In mammals, MEIOB and its partner SPATA22 form a heterodimer, ensuring their effective localization on single-strand DNA (ssDNA) and proper synapsis processes. Mutations in human MEIOB (hMEIOB) cause human infertility attributed to the failure of its interaction with human SPATA22 (hSPATA22) and ssDNA binding. However, the detailed mechanism is still unclear. In our study, truncated or full-length hMEIOB and hSPATA22 are traced by fused expression with fluorescent proteins (i.e., copGFP or mCherry), and the live cell imaging system is used to observe the expression and localization of the proteins. When transfected alone, hMEIOB accumulates in the cytoplasm. Interestingly, a covered NLS in the OB domain of hMEIOB is identified, which can be exposed by hSPATA22 and is necessary for the nuclear localization of hMEIOB. When hSPATA22 loses its hMEIOB interacting domain or NLS, the nuclear localization of hMEIOB is aborted. Collectively, our results prove that the NLS in the OB domain of hMEIOB and interaction with hSPATA22 are required for hMEIOB nuclear localization.

Keywords: MEIOB; NLS; OB domain; SPATA22; protein interaction.

MeSH terms

  • Animals
  • Cell Cycle Proteins / metabolism
  • Cell Nucleus* / metabolism
  • DNA-Binding Proteins* / genetics
  • Homologous Recombination
  • Humans
  • Mammals / metabolism
  • Meiosis
  • Mutation

Substances

  • DNA-Binding Proteins
  • SPATA22 protein, human
  • Cell Cycle Proteins
  • MEIOB protein, human

Grants and funding

This work was supported by the grants from the National Natural Science Foundation of China (No. 31771588), the Strategic Collaborative Research Program of the Ferring Institute of Reproductive Medicine (No. FIRMC200509), the Key Research and Development Project of Hubei Province (No. 2021BCA111), and the Translational Medicine and Interdisciplinary Research (No. ZNJC201928) to M.L.