N6-methyladenosine RNA Binding Protein Research Articles

Comprehensive Analysis Revealed the Potential Roles of N6-Methyladenosine (m6A) Mediating E. coli F18 Susceptibility in IPEC-J2 Cells.

Post-weaning diarrhea caused by enterotoxigenic Escherichia coli F18 (E. coli F18) causes significant economic losses for pig producers. N6-methyladenosine (m6A) is a highly abundant epitranscriptomic marker that has been found to be involved in regulating the resistance of host cells to pathogenic infection, but its potential role in E. coli F18-exposed intestinal porcine epithelial cells (IPEC-J2) remains undetermined. Here, we demonstrated that m6A and its regulators modulate E. coli F18 susceptibility. Briefly, we revealed that the Wilms' tumor 1-associating protein (WTAP) expressions were markedly elevated in IPEC-J2 cells upon E. coli F18 exposure. WTAP are required for the regulation of E. coli F18 adhesion in IPEC-J2 cells. Additionally, WTAP knockdown significantly suppressed m6A level at N-acetyllactosaminide beta-1,6-N-acetylglucosaminyl-transferase (GCNT2) 3'UTR, resulting in the enhancement of TH N6-methyladenosine RNA binding protein 2 (YTHDF2)-mediated GCNT2 mRNA stability. Subsequently, the altered GCNT2 expressions could inhibit the glycosphingolipid biosynthesis, thus improving resistance to E. coli F18 infection in IPEC-J2. Collectively, our analyses highlighted the mechanism behind the m6A-mediated management of E. coli F18 susceptibility, which will aid in the development of novel approaches that protect against bacterial diarrhea in piglets.

A Saccharomyces cerevisiae model and screen to define the functional consequences of oncogenic histone missense mutations.

Somatic missense mutations in histone genes turn these essential proteins into oncohistones, which can drive oncogenesis. Understanding how missense mutations alter histone function is challenging in mammals as mutations occur in a single histone gene. For example, described oncohistone mutations predominantly occur in the histone H3.3 gene, despite the human genome encoding 15 H3 genes. To understand how oncogenic histone missense mutations alter histone function, we leveraged the budding yeast model, which contains only 2 H3 genes, to explore the functional consequences of oncohistones H3K36M, H3G34W, H3G34L, H3G34R, and H3G34V. Analysis of cells that express each of these variants as the sole copy of H3 reveals that H3K36 mutants show different drug sensitivities compared to H3G34 mutants. This finding suggests that changes to proximal amino acids in the H3 N-terminal tail alter distinct biological pathways. We exploited the caffeine-sensitive growth of H3K36-mutant cells to perform a high copy suppressor screen. This screen identified genes linked to histone function and transcriptional regulation, including Esa1, a histone H4/H2A acetyltransferase; Tos4, a forkhead-associated domain-containing gene expression regulator; Pho92, an N6-methyladenosine RNA-binding protein; and Sgv1/Bur1, a cyclin-dependent kinase. We show that the Esa1 lysine acetyltransferase activity is critical for suppression of the caffeine-sensitive growth of H3K36R-mutant cells while the previously characterized binding interactions of Tos4 and Pho92 are not required for suppression. This screen identifies pathways that could be altered by oncohistone mutations and highlights the value of yeast genetics to identify pathways altered by such mutations.