Genome-wide genetic screen identifies host ubiquitination as important for L. pneumophila Dot/Icm effector translocation

Ong, SY; Schuelein, R; Wibawa, RR; Thomas, DW; Handoko, Y; Freytag, S; Bahlo, M; Simpson, KJ; Hartland, EL

Author(s): Ong, SY; Schuelein, R; Wibawa, RR; Thomas, DW; Handoko, Y; Freytag, S; Bahlo, M; Simpson, KJ; Hartland, EL;
Details: Publication Year 2021-05-26,Volume 23,Issue #10,Page e13368
Journal Title: Cellular Microbiology
Publication Type: epub ahead of print
Abstract: The Dot/Icm system of Legionella pneumophila is essential for virulence and delivers a large repertoire of effectors into infected host cells to create the Legionella containing vacuole. Since the secretion of effectors via the Dot/Icm system does not occur in the absence of host cells, we hypothesized that host factors actively participate in Dot/Icm effector translocation. Here we employed a high-throughput, genome-wide siRNA screen to systematically test the effect of silencing 18,120 human genes on translocation of the Dot/Icm effector, RalF, into HeLa cells. For the primary screen, we found that silencing of 119 genes led to increased translocation of RalF, while silencing of 321 genes resulted in decreased translocation. Following secondary screening, 70 genes were successfully validated as 'high confidence' targets. Gene set enrichment analysis of siRNAs leading to decreased RalF translocation, showed that ubiquitination was the most highly overrepresented category in the pathway analysis. We further showed that two host factors, the E2 ubiquitin conjugating enzyme, UBE2E1, and the E3 ubiquitin ligase, CUL7, were important for supporting Dot/Icm translocation and L. pneumophila intracellular replication. In summary, we identified host ubiquitin pathways as important for the efficiency of Dot/Icm effector translocation by L. pneumophila, suggesting that host-derived ubiquitin-conjugating enzymes and ubiquitin ligases participate in the translocation of Legionella effector proteins and influence intracellular persistence and survival. This article is protected by copyright. All rights reserved.
Publisher: Wiley
Research Division(s): Population Health And Immunity
PubMed ID: 34041837
Publisher's Version: https://doi.org/10.1111/cmi.13368
Terms of Use/Rights Notice: Refer to copyright notice on published article.

Creation Date: 2021-06-02 01:36:30

Last Modified: 2021-11-10 10:46:26