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Ddx41 function in erythropoiesis
AB
Figure 6. ATM inhibition partially suppresses ddx41 mutant anemia. (A) Representative images of o-dianisidine staining and corresponding levels of staining from sibling controls (left) and ddx41 mutants (right) treated with dimethyl sulfoxide (DMSO) (top), 30 nM KU60019 (Ataxia-telengiectasia-mutated inhibitor [ATMi], mid- dle), and 30 nM AZ20 (Ataxia-telengiectasia and Rad3-related inhibitor[ATRi], bottom). Numbers on bottom left corner indicate the fraction of embryos with the same phenotype as the one depicted in the image. scale bars =100 μm. (B) Graph depicting frequency of designated o-dianisidine staining levels in sibling controls and ddx41 mutants at 40 hours post fertilization (hpf) treated with DMSO vehicle control, 30 nM KU60019 (ATMi), and 30 nM AZ20 (ATRi). Graphs display frequency of embryos with each phenotype with P-values calculated with Chi-squared test, *P<0.05, ****P≤0.0001. For o-dianisidine staining, n=36-67 embryos per experiment.
demonstrated that deficiency of ddx41 triggers cell cycle arrest via activation of ATM and ATR, which ultimately mediates a decrease in proliferation and maturation of erythrocytic progenitors in ddx41 mutants. These findings establish a critical function for Ddx41 in promoting healthy erythropoiesis by suppressing genomic stress and present a potential role for ATM and ATR signaling in DDX41-mutant pathologies.
Disclosures
No conflicts of interest to disclose.
Contributions
JTW and TVB designed the project experimental approach; JTW, ES, RW, and TVB performed the experiments; VG per-
formed bioinformatics analysis; JTW and TVB analyzed the data; JTW and TVB wrote and edited the manuscript; all authors reviewed and approved the manuscript.
Acknowledgments
This work was funded by American Cancer Society RSG- 129527-DDC, DOD BM180109, NIH 1R01DK121738- 01A1 and the Edward P. Evans Foundation (to TVB), NIH MSTP training grant T32GM007288-45 and F30 fellowship 1F30HL142161 (to JTW), and NIH 1R01GM057829-23 to Charles Query for support of VG. We also want to acknowledge the assistance of numerous core facilities at Albert Einstein College of Medicine including Flow Cytometry, Analytical Imaging, and Genomics Facilities (funded by NCI Cancer Grant P30CA013330), and the Zebrafish Core Facility.
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