Abstract

Polycomb repressive complex 1 (PRC1) modifies chromatin through catalysis of histone H2A lysine 119 monoubiquitination (H2AK119ub1). RING1 and RNF2 interchangeably serve as the catalytic subunit within PRC1. Pathogenic missense variants in PRC1 core components reveal functions of these proteins that are obscured in knockout models. While Ring1a knockout models remain healthy, the microcephaly and neuropsychiatric phenotypes associated with a pathogenic RING1 missense variant implicate unappreciated functions. Using an in vitro model of neurodevelopment, we observe that RING1 contributes to the broad placement of H2AK119ub1, and that its targets overlap with those of RNF2. PRC1 complexes harboring hypomorphic RING1 bind target loci but do not catalyze H2AK119ub1, reducing H2AK119ub1 by preventing catalytically active complexes from accessing the locus. This results in delayed DNA damage repair and cell cycle progression in neural progenitor cells (NPCs). Conversely, reduced H2AK119ub1 due to hypomorphic RING1 does not generate differential expression that impacts NPC differentiation. In contrast, hypomorphic RNF2 generates a greater reduction in H2AK119ub1 that results in both delayed DNA repair and widespread transcriptional changes. These findings suggest that the DNA damage response is more sensitive to H2AK119ub1 dosage change than is regulation of gene expression.

Here, the authors establish a human in vitro model of neurodevelopment to investigate an allelic series of clinically relevant RING1 and RNF2 missense variants. The observations reveal that missense variants function according to a dominant-negative genetic mechanism.

Details

Title
RING1 missense variants reveal sensitivity of DNA damage repair to H2A monoubiquitination dosage during neurogenesis
Author
Ryan, C. W. 1   VIAFID ORCID Logo  ; Regan, S. L. 2 ; Mills, E. F. 2 ; McGrath, B. T. 2 ; Gong, E. 2 ; Lai, Y. T. 2 ; Sheingold, J. B. 2 ; Patel, K. 2   VIAFID ORCID Logo  ; Horowitz, T. 2 ; Moccia, A. 2   VIAFID ORCID Logo  ; Tsan, Y. C. 2 ; Srivastava, A. 3 ; Bielas, S. L. 4   VIAFID ORCID Logo 

 University of Michigan Medical School, Cellular and Molecular Biology Program, Ann Arbor, USA (GRID:grid.214458.e) (ISNI:0000000086837370); University of Michigan Medical School, Medical Science Training Program, Ann Arbor, USA (GRID:grid.214458.e) (ISNI:0000000086837370); University of Michigan Medical School, Department of Human Genetics, Ann Arbor, USA (GRID:grid.214458.e) (ISNI:0000000086837370) 
 University of Michigan Medical School, Department of Human Genetics, Ann Arbor, USA (GRID:grid.214458.e) (ISNI:0000000086837370) 
 University of Michigan Medical School, Department of Human Genetics, Ann Arbor, USA (GRID:grid.214458.e) (ISNI:0000000086837370); Department of Medical Genetics, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow, India (GRID:grid.263138.d) (ISNI:0000 0000 9346 7267) 
 University of Michigan Medical School, Cellular and Molecular Biology Program, Ann Arbor, USA (GRID:grid.214458.e) (ISNI:0000000086837370); University of Michigan Medical School, Department of Human Genetics, Ann Arbor, USA (GRID:grid.214458.e) (ISNI:0000000086837370); University of Michigan Medical School, Department of Pediatrics, Ann Arbor, USA (GRID:grid.214458.e) (ISNI:0000000086837370); University of Michigan Medical School, Neuroscience Graduate Program, Ann Arbor, USA (GRID:grid.214458.e) (ISNI:0000000086837370) 
Pages
7931
Publication year
2024
Publication date
2024
Publisher
Nature Publishing Group
e-ISSN
20411723
Source type
Scholarly Journal
Language of publication
English
ProQuest document ID
3102573947
Copyright
© The Author(s) 2024. This work is published under http://creativecommons.org/licenses/by-nc-nd/4.0/ (the “License”). Notwithstanding the ProQuest Terms and Conditions, you may use this content in accordance with the terms of the License.