TY - JOUR
T1 - Catabolite repression control protein antagonist, a novel player in Pseudomonas aeruginosa carbon catabolite repression control
AU - Sonnleitner, Elisabeth
AU - Bassani, Flavia
AU - Cianciulli Sesso, Anastasia
AU - Brear, Paul
AU - Lilic, Branislav
AU - Davidovski, Lovro
AU - Resch, Armin
AU - Luisi, Ben F.
AU - Moll, Isabella
AU - Bläsi, Udo
N1 - Funding Information:
The work was supported by the Austrian Science Fund (FWF; www.fwf.ac.at/en ) through projects P28711-B22 (UB and ES) and P26946-B20 (IM). ACS and BL were supported through the FWF funded doctoral program RNA-Biology W-1207. BFL was supported by a Wellcome Trust Investigator award (200873/Z/16/Z).
Publisher Copyright:
Copyright © 2023 Sonnleitner, Bassani, Cianciulli-Sesso, Brear, Lilic, Davidovski, Resch, Luisi, Moll and Bläsi.
PY - 2023
Y1 - 2023
N2 - In the opportunistic human pathogen Pseudomonas aeruginosa (Pae), carbon catabolite repression (CCR) orchestrates the hierarchical utilization of N and C sources, and impacts virulence, antibiotic resistance and biofilm development. During CCR, the RNA chaperone Hfq and the catabolite repression control protein Crc form assemblies on target mRNAs that impede translation of proteins involved in uptake and catabolism of less preferred C sources. After exhaustion of the preferred C-source, translational repression of target genes is relieved by the regulatory RNA CrcZ, which binds to and acts as a decoy for Hfq. Here, we asked whether Crc action can be modulated to relieve CCR after exhaustion of a preferred carbon source. As Crc does not bind to RNA per se, we endeavored to identify an interacting protein. In vivo co-purification studies, co-immunoprecipitation and biophysical assays revealed that Crc binds to Pae strain O1 protein PA1677. Our structural studies support bioinformatics analyzes showing that PA1677 belongs to the isochorismatase-like superfamily. Ectopic expression of PA1677 resulted in de-repression of Hfq/Crc controlled target genes, while in the absence of the protein, an extended lag phase is observed during diauxic growth on a preferred and a non-preferred carbon source. This observations indicate that PA1677 acts as an antagonist of Crc that favors synthesis of proteins required to metabolize non-preferred carbon sources. We present a working model wherein PA1677 diminishes the formation of productive Hfq/Crc repressive complexes on target mRNAs by titrating Crc. Accordingly, we propose the name CrcA (catabolite repression control protein antagonist) for PA1677.
AB - In the opportunistic human pathogen Pseudomonas aeruginosa (Pae), carbon catabolite repression (CCR) orchestrates the hierarchical utilization of N and C sources, and impacts virulence, antibiotic resistance and biofilm development. During CCR, the RNA chaperone Hfq and the catabolite repression control protein Crc form assemblies on target mRNAs that impede translation of proteins involved in uptake and catabolism of less preferred C sources. After exhaustion of the preferred C-source, translational repression of target genes is relieved by the regulatory RNA CrcZ, which binds to and acts as a decoy for Hfq. Here, we asked whether Crc action can be modulated to relieve CCR after exhaustion of a preferred carbon source. As Crc does not bind to RNA per se, we endeavored to identify an interacting protein. In vivo co-purification studies, co-immunoprecipitation and biophysical assays revealed that Crc binds to Pae strain O1 protein PA1677. Our structural studies support bioinformatics analyzes showing that PA1677 belongs to the isochorismatase-like superfamily. Ectopic expression of PA1677 resulted in de-repression of Hfq/Crc controlled target genes, while in the absence of the protein, an extended lag phase is observed during diauxic growth on a preferred and a non-preferred carbon source. This observations indicate that PA1677 acts as an antagonist of Crc that favors synthesis of proteins required to metabolize non-preferred carbon sources. We present a working model wherein PA1677 diminishes the formation of productive Hfq/Crc repressive complexes on target mRNAs by titrating Crc. Accordingly, we propose the name CrcA (catabolite repression control protein antagonist) for PA1677.
KW - carbon catabolite repression
KW - carbon catabolite repression control protein
KW - Hfq
KW - post-transcriptional control
KW - Pseudomonas
UR - http://www.scopus.com/inward/record.url?scp=85160046678&partnerID=8YFLogxK
U2 - 10.3389/fmicb.2023.1195558
DO - 10.3389/fmicb.2023.1195558
M3 - Article
AN - SCOPUS:85160046678
VL - 14
JO - Frontiers in Microbiology
JF - Frontiers in Microbiology
SN - 1664-302X
M1 - 1195558
ER -