A universal stress protein in Mycobacterium smegmatis sequesters the cAMP-regulated lysine acyltransferase and is essential for biofilm formation

Abstract

Universal stress proteins (USPs) are present in many bacteria, and their expression is enhanced under various environmental stresses. We have previously identified a USP in Mycobacterium smegmatis that is a product of the msmeg_4207 gene and is a substrate for a cAMP-regulated protein lysine acyltransferase (KATms; MSMEG_5458). Here, we explored the role of this USP (USP4207) in M. smegmatis and found that its gene is present in an operon that also contains genes predicted to encode a putative tripartite tricarboxylate transporter (TTT). Transcription of the TTT-usp4207 operon was induced in the presence of citrate and tartrate, perhaps by the activity of a divergent histidine kinase-response regulator gene pair. A usp4207-deleted strain had rough colony morphology and reduced biofilm formation compared with the WT strain; however, both normal colony morphology and biofilm formation were restored in a Δusp4207Δkatms strain. We identified several proteins whose acetylation was lost in the Δkatms strain, and whose transcript levels increased in M. smegmatis biofilms along with that of USP4207, suggesting that USP4207 insulates KATms from its other substrates in the cell. We propose that USP4207 sequesters KATms from diverse substrates whose activities are down-regulated by acylation but are required for biofilm formation, thus providing a defined role for this USP in mycobacterial physiology and stress responses.

Environmental stressor assessment of hydrocarbonoclastic bacteria biofilms from a marine oil spill

“…Notwithstanding the above, further studies are needed to get the full picture of what happens to the usp A expression over time for the present Micrococcus case under the stressor evaluated. On the other hand, usp gene expression levels are determined by the carbon source as a substrate, in the case of some actinobacteria such as Mycobacterium , citrate (tricarboxylic acid) could regulate the usp expression and cause a factor of 10 increase [108] . For Micrococcus , to the knowledge of the present authors, there are no specific quantitative data of usp A gene expression using crude oil as a substrate under stress conditions.…”

Ag NCs as a potent antibiofilm agent against pathogenic Pseudomonas aeruginosa and Acinetobacter baumannii and drug-resistant Bacillus subtilis by affecting chemotaxis and flagellar assembly pathway genes

“…We had set up the pellicle (biofilm at the liquid-air interface) following the standard protocol. 27 At first, we had investigated the biofilm inhibition efficacy of Ag NCs. At the initiation of biofilm formation, Ag NCs were added to the culture.…”

Bioinformatics Investigations of Universal Stress Proteins from Mercury-Methylating Desulfovibrionaceae

“…A list of Desulfovibrionaceae genomes predicted to be mercury methylators according to the presence of the hgcAB gene pair are available on the data page of the Biogeochemical Transformations at Critical Interfaces project of the Oak Ridge National Laboratory’s Mercury Science Focus Area [ 12 , 20 ]. We are interested in genes that encode the universal stress protein (USP) domain (Protein Family (Pfam) Identifiers: Usp, pfam00582 or PF00582), since they aid bacteria in (1) responding to extreme conditions; and (2) the formation as well as maintenance of adherent bacteria communities termed biofilms [ 21 , 22 , 23 , 24 ]. Biofilms can methylate mercury (Hg) at higher rates than unattached bacteria and are a location for mercury methylation in the environment [ 11 ].…”