Poster Presentation The 48th Lorne Conference on Protein Structure and Function 2023

Structure based drug design against HOXA1 (#305)

Vinodini S Madugalle 1 2 , Louise E Purton 2 3 , Jessica K Holien 1
  1. RMIT University, Bundoora, VIC, Australia
  2. St Vincents's Institute of Medical Research, Melbourne, VIC, Australia
  3. Department of Medicine at St Vincent's Hospital, University of Melbourne, Melbourne, VIC, Australia

Myelodysplastic syndromes (MDS), a blood cancer that significantly increases with age, currently has no cure available to a majority of the cohort (Leukemia foundation 2019). Upregulation of the Hoxa1 (homeobox a1) protein causes MDS in mice and we have found that HOXA1 transcripts are upregulated in approximately 50% of MDS patients. A therapy targeting upregulated HOXA1 may provide a promising option for MDS patients. HOXA1 is a transcription factor and acts by binding to a co factor PBX1 (pre-B-cell leukemia transcription factor 1) and DNA, which then leads to its target gene regulation (De Kumar et al., 2017; Sprules et al., 2003). The structure of HOXA1 has not been solved. However, HOXA1 shares a sequence identity of approximately 83% with HOXB1, for which the crystal structure bound to PBX1 and DNA has been published (Piper, 1999). In this project we predicted the structure of HOXA1 computationally using homology modelling and modelled its interactions with PBX1 and DNA. A molecular dynamics simulation of the HOXA1/PBX1/DNA complex was performed to obtain a minimal energy conformation before using the protein to conduct a virtual screen.  A total of 104 compounds identified are currently being analysed via surface plasmon resonance to test their direct binding to the HOXA1 protein. The hit compounds will progress onto cellular assays to identify compounds that target Hoxa1-overexpressing cells while sparing healthy cells.

 

  1. De Kumar, B., Parker, H. J., Paulson, A., Parrish, M. E., Zeitlinger, J., & Krumlauf, R. (2017, Dec 1). Hoxa1 targets signaling pathways during neural differentiation of ES cells and mouse embryogenesis. Dev Biol, 432(1), 151-164. https://doi.org/10.1016/j.ydbio.2017.09.033
  2. Piper, D. E., Batchelor, A.H., Chang, Cleary, M.L.,Wolberger, C.*. ( 1999, February 19). HOXB1-PBX-DNA.pdf. Cell, Vol. 96, 587–597.
  3. Sprules, T., Green, N., Featherstone, M., & Gehring, K. (2003, Jan 10). Lock and key binding of the HOX YPWM peptide to the PBX homeodomain. J Biol Chem, 278(2), 1053-1058. https://doi.org/10.1074/jbc.M207504200