Year: 2025
Type: article
Abstract: Two-component systems (TCSs) in bacteria are often involved in the global regulation of various physiological activities and behaviours. This study investigated the GacSA TCS and DJ41_1407 transcriptional sensor adjacent to GacA in Acinetobacter baumannii ATCC 19606. The relationship between GacS, GacA, and DJ41_1407 and their functions and signal transduction mechanisms are described. A. baumannii ATCC 19606 mutants, ∆gacS, ∆gacA, and ∆DJ41_1407, were generated using markerless mutation and cultured in LB medium, then collected for RNA sequencing. It was found that GacS, GacA, and DJ41_1407 regulate a series of genes involved in carbon metabolism. Quantitative reverse transcription PCR (qRT-PCR) results showed that DJ41_1407 and GacA may regulate the expression of adh4, ipdC, iacH, and paa. Phos-tag™ results revealed that GacS plays a more significant role in GacA phosphorylation. GacA regulated colony size and growth conditions in rich medium. Compared to the wild-type strain, the ∆gacA and ∆gacSA mutants exhibited smaller colony sizes, and mutation of the gacS, gacA, and DJ41_1407 genes also reduced bacterial virulence as determined by the Galleria mellonella infection assay. GacA also plays a crucial role in modulating antibiotic resistance, and the ∆gacA∆DJ41_1407 mutant demonstrated greater susceptibility to antibiotics. These results highlight the multiple functions regulated by the GacSA global TCS in A. baumannii ATCC 19606.
Authors: Yee-Huan Toh, Meng-Yun Wen, Guang-Huey Lin
Institution: Tzu Chi University
Language: English
Subfield: Genetics
Domain: Life Sciences
Open Access status: gold
Estimated APC paid: $3,499
Funder: Tzu Chi University
OpenAlex ID: W4415808571