Life stage-specific poly(A) site selection regulated by Trypanosoma brucei DRBD18

• 成果类型: Article
• 署名作者: Bard, Jonathan E.; Tylec, Brianna L.; Dubey, Ashutosh P.; Lamb, Natalie A.; Yergeau, Donald A.; Read, Laurie K.
• 署名单位: State University of New York (SUNY) System; University at Buffalo, SUNY; State University of New York (SUNY) System; University at Buffalo, SUNY; State University of New York (SUNY) System; University at Buffalo, SUNY; United States Department of Energy (DOE); National Renewable Energy Laboratory - USA
• 刊物名称: PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
• ISSN/ISSBN: 0027-12093
• DOI: 10.1073/pnas.2403188121
• 发表日期: 2024-07-16
• 关键词: messenger-rna; cycle stages; polyadenylation; expression; abundance; STABILITY; region

摘要

The kinetoplastid parasite, Trypanosoma brucei, , undergoes a complex life cycle entailing slender and stumpy bloodstream forms in mammals and procyclic and metacyclic forms (MFs) in tsetse fly hosts. The numerous gene regulatory events that underlie T. brucei differentiation between hosts, as well as between active and quiescent stages within each host, take place in the near absence of transcriptional control. Rather, differentiation is controlled by RNA-- binding proteins (RBPs) that associate with mRNA 3 ' ' untranslated regions (3 ' UTRs) ' UTRs) to impact RNA stability and translational efficiency. DRBD18 is a multifunctional T. brucei RBP, shown to impact mRNA stability, translation, export, and processing. Here, we use single- cell RNAseq to characterize transcriptomic changes in cell populations that arise upon DRBD18 depletion, as well as to visualize transcriptome-wide- wide alterations to 3 ' UTR ' UTR length. We show that in procyclic insect stages, DRBD18 represses expression of stumpy bloodstream form and MF transcripts. Additionally, DRBD18 regulates the 3 ' UTR ' UTR lengths of over 1,500 transcripts, typically promoting the use of distal polyadenylation sites, and thus the inclusion of 3 ' UTR ' UTR regulatory elements. Remarkably, comparison of polyadenylation patterns in DRBD18 knockdowns with polyadenylation patterns in stumpy bloodstream forms shows numerous similarities, revealing a role for poly(A) site selection in developmental gene regulation, and indicating that DRBD18 controls this process for a set of transcripts. RNA immunoprecipitation supports a direct role for DRBD18 in poly(A) site selection. This report highlights the importance of alternative polyadenylation in T. brucei developmental control and identifies a critical RBP in this process.