Blockage of O-linked glycan biosynthesis in Burkholderia is toxic: Tn7_ogcI_validation

ABSTRACT: Burkholderia species are associated with several life-threatening human infections, often resulting in high morbidity and mortality rates due to their innate resistance to antibiotics. To improve clinical outcomes, new therapies targeting conserved, yet unique, Burkholderia pathways are needed. One such pathway is the Burkholderia O-linked protein glycosylation system, essential for virulence in Burkholderia cenocepacia and Burkholderia pseudomallei. This system relies on the O-Glycosylation gene Cluster (OGC), a five-gene cluster sufficient and required for the generation of a trisaccharide β-Gal-(1,3)–α-GalNAc-(1,3)–β-GalNAc used for protein glycosylation, and the distally encoded oligosaccharyltransferase, pglL, responsible for ligating glycans to glycoproteins. Previous work has shown that the OGC cluster can be removed, but individual mutations associated with late-stage glycan biosynthesis are essential. Here, we explore the essentiality of late-stage O-linked glycan biosynthesis in B. cenocepacia, revealing that the completion and translocation of the O-linked trisaccharide is necessary for viability and bacterial fitness. Using inducible systems, we demonstrate toxicity dependent on multiple OGC genes and the initiation of O-linked glycan biosynthesis. Upon loss of late-stage biosynthesis, mutants exhibit notable growth defects and profound sensitivity to stresses. Proteomics and glycoproteomic analysis show that blocking late-stage glycan biosynthesis inhibits protein glycosylation and drives large membrane proteomic changes. Finally, we demonstrate that OGC mediated toxicity is not limited to blockages but can also occur via the overexpression of steps within O-linked glycan biosynthesis. Combined, these findings suggest that the O-linked glycan biosynthesis pathway of B. cenocepacia is extremely sensitive to dysregulation and may be an ideal target for the development of antimicrobial therapies.

INSTRUMENT(S):

ORGANISM(S): Burkholderia Cenocepacia K56-2valvano

SUBMITTER: Nichollas Scott  

LAB HEAD: Nichollas E. Scott

PROVIDER: PXD055576 | Pride | 2025-10-22

REPOSITORIES: Pride