Structure-function relationship of ASH1L and histone H3K36 and H3K4 methylation.
Vann, K.R., Sharma, R., Hsu, C.C., Devoucoux, M., Tencer, A.H., Zeng, L., Lin, K., Zhu, L., Li, Q., Lachance, C., Ospina, R.R., Tong, Q., Cheung, K.L., Yang, S., Biswas, S., Xuan, H., Gatchalian, J., Alamillo, L., Wang, J., Jang, S.M., Klein, B.J., Lu, Y., Ernst, P., Strahl, B.D., Rothbart, S.B., Walsh, M.J., Cleary, M.L., Cote, J., Shi, X., Zhou, M.M., Kutateladze, T.G.(2025) Nat Commun 16: 2235-2235
- PubMed: 40044670 
- DOI: https://doi.org/10.1038/s41467-025-57556-5
- Primary Citation of Related Structures:  
8VLD, 8VLF, 8VLH - PubMed Abstract: 
The histone H3K36-specific methyltransferase ASH1L plays a critical role in development and is frequently dysregulated in human diseases, particularly cancer. Here, we report on the biological functions of the C-terminal region of ASH1L encompassing a bromodomain (ASH1L BD ), a plant homeodomain (ASH1L PHD ) finger, and a bromo-adjacent homology (ASH1L BAH ) domain, structurally characterize these domains, describe their mechanisms of action, and explore functional crosstalk between them. We find that ASH1L PHD recognizes H3K4me2/3, whereas the neighboring ASH1L BD and ASH1L BAH have DNA binding activities. The DNA binding function of ASH1L BAH is a driving force for the association of ASH1L with the linker DNA in the nucleosome, and the large interface with ASH1L PHD stabilizes the ASH1L BAH fold, merging two domains into a single module. We show that ASH1L is involved in embryonic stem cell differentiation and co-localizes with H3K4me3 but not with H3K36me2 at transcription start sites of target genes and genome wide, and that the interaction of ASH1L PHD with H3K4me3 is inhibitory to the H3K36me2-specific catalytic activity of ASH1L. Our findings shed light on the mechanistic details by which the C-terminal domains of ASH1L associate with chromatin and regulate the enzymatic function of ASH1L.
- Department of Pharmacology, University of Colorado School of Medicine, Aurora, CO, 80045, USA.
Organizational Affiliation: