Student Posters 51st Lorne Proteins Conference 2026

Exploring the Interaction Between Annexin A11 and TDP-43: Structural Insights into Self- and Co-Assembly Mechanisms   (#129)

Andrea Gelardo Serrano 1 , Miguel Mompeán García 1 , Gustavo A Titaux Delgado 1
  1. Instituto de Física Química Blas Cabrera-IQF/CSIC, Madrid, SPAIN, Spain

Annexin A11 (ANX11) is a calcium- and lipid-binding protein linked to neurodegenerative diseases through its interaction with the RNA-binding protein TDP-43 (1). These interactions, mediated by low-complexity regions (LCRs), promote the formation of heterotypic amyloid assemblies (2). While the prion-like domain of TDP-43 has been extensively characterized (3), the structural and conformational features of ANX11 remain poorly understood.

We present our ongoing investiations on the interaction between TDP-43 and a series of ANX11 constructs comprising its LCD and flanking regions. Using biophysical and biochemical approaches, we analyze the conformational ensemble of the ANX11 N-terminal constructs with and without the C-terminal domain (CTD) of TDP-43, examining how these interactions modulate self- and co-assembly.

This research aims at shedding light on the conformational determinants driving ANX11–TDP-43 association, providing insight into how these interactions may contribute to heteromeric assemblies implicated in disease.

 

  1. 1- Robinson JL, Suh E, Xu Y, Hurtig HI, Elman L, McMillan CT, Irwin DJ, Porta S, Van Deerlin VM, Lee EB. Annexin A11 aggregation in FTLD-TDP type C and related neurodegenerative disease proteinopathies. Acta Neuropathol. 2024 Jun 19;147(1):104. doi: 10.1007/s00401-024-02753-7.
  2. 2- Arseni D, Chen R, Murzin AG, Peak-Chew SY, Garringer HJ, Newell KL, Kametani F, Robinson AC, Vidal R, Ghetti B, Hasegawa M, Ryskeldi-Falcon B. TDP-43 forms amyloid filaments with a distinct fold in type A FTLD-TDP. Nature. 2023 Aug;620(7975):898-903. doi: 10.1038/s41586-023-06405-w.
  3. 3- Pantoja-Uceda D, Stuani C, Laurents DV, McDermott AE, Buratti E, Mompeán M. Phe-Gly motifs drive fibrillization of TDP-43's prion-like domain condensates. PLoS Biol. 2021 Apr 28;19(4):e3001198. doi: 10.1371/journal.pbio.3001198.