{"entity": "researcher", "timestamp": "2026-08-20T20:37:35.585Z", "family": "Brown", "given": "Pamela J B", "initials": "PJB", "orcid": "0000-0002-7558-7155", "affiliations": ["Division of Biological Sciences, University of Missouri, Columbia, MO 65211."], "links": {"self": {"href": "https://publications-affiliated.scilifelab.se/researcher/724518d7b8f24b438cd852bea2119e61.json"}, "display": {"href": "https://publications-affiliated.scilifelab.se/researcher/724518d7b8f24b438cd852bea2119e61"}}, "publications": [{"entity": "publication", "iuid": "6fff9ff3f03949ecb95cf79ce2249209", "links": {"self": {"href": "https://publications-affiliated.scilifelab.se/publication/6fff9ff3f03949ecb95cf79ce2249209.json"}, "display": {"href": "https://publications-affiliated.scilifelab.se/publication/6fff9ff3f03949ecb95cf79ce2249209"}}, "title": "Activation of the ChvG-ChvI pathway promotes survival during cell wall stress in Agrobacterium tumefaciens.", "authors": [{"family": "Bouchier", "given": "Jacob M", "initials": "JM"}, {"family": "Knebel", "given": "Emily", "initials": "E"}, {"family": "Amstutz", "given": "Jennifer", "initials": "J"}, {"family": "Torrens", "given": "Gabriel", "initials": "G"}, {"family": "Santiago-Collazo", "given": "Gustavo", "initials": "G"}, {"family": "McCurry", "given": "Carli", "initials": "C"}, {"family": "Weisberg", "given": "Alexandra J", "initials": "AJ"}, {"family": "Cava", "given": "Felipe", "initials": "F"}, {"family": "Brown", "given": "Pamela J B", "initials": "PJB", "orcid": "0000-0002-7558-7155", "researcher": {"href": "https://publications-affiliated.scilifelab.se/researcher/724518d7b8f24b438cd852bea2119e61.json"}}], "type": "journal article", "published": "2025-07-01", "journal": {"title": "Mol. Biol. Cell", "issn": "1939-4586", "volume": "36", "issue": "7", "pages": "ar84", "issn-l": "1059-1524"}, "abstract": "Agrobacterium tumefaciens shifts from a free-living soil bacterium to a plant-invading state upon encountering the plant root microenvironment. The acid-induced two-component sensor system ChvG-ChvI drives this shift and triggers a complex transcriptional program that promotes host invasion and survival against host immune defenses. Remarkably, ChvG-ChvI is also activated under cell wall stress conditions, suggesting that the transcriptional response may have a broader function. Here, we find that blocking cell wall synthesis either genetically or chemically leads to ChvG-ChvI activation. Mutations in key cell wall synthesis enzymes, such as penicillin-binding protein 1a and FtsW, suppress ChvG-ChvI activation in cell wall stress inducing conditions, suggesting that providing structural integrity is a primary function of the ChvG-ChvI regulon. Here, we investigated regulon components for this function. First, deletion of exoA, a gene required for production of the exopolysaccharide succinoglycan, confers resistance to multiple \u03b2-lactam antibiotics targeting different enzymes. Next, a class D \u03b2-lactamase is expressed that may contribute to the high level of \u03b2-lactam resistance in A. tumefaciens. Finally, outer membrane proteins are upregulated, suggesting that outer membrane remodeling may compensate for the accumulation of cell wall damage by providing structural integrity. Overall, we expand our understanding of mechanisms driving ChvG-ChvI activation and \u03b2-lactam resistance in a bacterial plant pathogen.", "doi": "10.1091/mbc.E24-12-0546", "pmid": "40372762", "labels": [], "xrefs": [{"db": "pmc", "key": "PMC12260177"}], "notes": [], "created": "2026-08-20T09:38:47.206Z", "modified": "2026-08-20T09:38:47.264Z"}, {"entity": "publication", "iuid": "7bb370fd048544a38252acd2f833c35e", "links": {"self": {"href": "https://publications-affiliated.scilifelab.se/publication/7bb370fd048544a38252acd2f833c35e.json"}, "display": {"href": "https://publications-affiliated.scilifelab.se/publication/7bb370fd048544a38252acd2f833c35e"}}, "title": "Activation of the ChvG-ChvI pathway promotes multiple survival strategies during cell wall stress in Agrobacterium tumefaciens", "authors": [{"family": "Bouchier", "given": "Jacob M", "initials": "JM"}, {"family": "Knebel", "given": "Emily", "initials": "E"}, {"family": "Amstutz", "given": "Jennifer", "initials": "J"}, {"family": "Torrens", "given": "Gabriel", "initials": "G"}, {"family": "Santiago-Collazo", "given": "Gustavo", "initials": "G"}, {"family": "McCurry", "given": "Carli", "initials": "C"}, {"family": "Weisberg", "given": "Alexandra J", "initials": "AJ"}, {"family": "Cava", "given": "Felipe", "initials": "F"}, {"family": "Brown", "given": "Pamela J B", "initials": "PJB", "orcid": "0000-0002-7558-7155", "researcher": {"href": "https://publications-affiliated.scilifelab.se/researcher/724518d7b8f24b438cd852bea2119e61.json"}}], "type": "posted-content", "published": "2024-12-11", "journal": {"issn-l": null}, "abstract": null, "doi": "10.1101/2024.12.10.627833", "pmid": null, "labels": [], "xrefs": [], "notes": [], "created": "2026-08-20T10:59:26.424Z", "modified": "2026-08-20T10:59:26.484Z"}, {"entity": "publication", "iuid": "dda09c0a9a3140d7b58c2557a6137522", "links": {"self": {"href": "https://publications-affiliated.scilifelab.se/publication/dda09c0a9a3140d7b58c2557a6137522.json"}, "display": {"href": "https://publications-affiliated.scilifelab.se/publication/dda09c0a9a3140d7b58c2557a6137522"}}, "title": "LD-transpeptidation is crucial for fitness and polar growth in Agrobacterium tumefaciens.", "authors": [{"family": "Aliashkevich", "given": "Alena", "initials": "A"}, {"family": "Guest", "given": "Thomas", "initials": "T", "orcid": "0000-0002-7868-0611", "researcher": {"href": "https://publications-affiliated.scilifelab.se/researcher/0210aa68ff384d83947c28a5a65917e1.json"}}, {"family": "Alvarez", "given": "Laura", "initials": "L", "orcid": "0000-0003-2429-7542", "researcher": {"href": "https://publications-affiliated.scilifelab.se/researcher/329d8b1460fe44789dbef53ea0493294.json"}}, {"family": "Gilmore", "given": "Michael C", "initials": "MC", "orcid": "0000-0002-6848-5134", "researcher": {"href": "https://publications-affiliated.scilifelab.se/researcher/afac90582c374ab9b15102bc27516d89.json"}}, {"family": "Rea", "given": "Daniel", "initials": "D", "orcid": "0009-0009-6904-1031", "researcher": {"href": "https://publications-affiliated.scilifelab.se/researcher/9f965bfb3ab44e82b84e6898fdf76ccf.json"}}, {"family": "Amstutz", "given": "Jennifer", "initials": "J"}, {"family": "Mateus", "given": "Andr\u00e9", "initials": "A", "orcid": "0000-0001-6870-0677", "researcher": {"href": "https://publications-affiliated.scilifelab.se/researcher/ebf0d242aa894a66b60828456bbc22aa.json"}}, {"family": "Schiffthaler", "given": "Bastian", "initials": "B", "orcid": "0000-0002-9771-467X", "researcher": {"href": "https://publications-affiliated.scilifelab.se/researcher/0d53293c611f44dda99e9249b1614132.json"}}, {"family": "Ruiz", "given": "I\u00f1igo", "initials": "I"}, {"family": "Typas", "given": "Athanasios", "initials": "A", "orcid": "0000-0002-0797-9018", "researcher": {"href": "https://publications-affiliated.scilifelab.se/researcher/d38ea7a531ad47cfa26df998f0e54dbe.json"}}, {"family": "Savitski", "given": "Mikhail M", "initials": "MM"}, {"family": "Brown", "given": "Pamela J B", "initials": "PJB", "orcid": "0000-0002-7558-7155", "researcher": {"href": "https://publications-affiliated.scilifelab.se/researcher/724518d7b8f24b438cd852bea2119e61.json"}}, {"family": "Cava", "given": "Felipe", "initials": "F", "orcid": "0000-0001-5995-718X", "researcher": {"href": "https://publications-affiliated.scilifelab.se/researcher/bbcff12a06814d54afea533e125a1213.json"}}], "type": "journal article", "published": "2024-10-00", "journal": {"title": "PLoS Genet", "issn": "1553-7404", "volume": "20", "issue": "10", "pages": "e1011449", "issn-l": "1553-7390"}, "abstract": "Peptidoglycan (PG), a mesh-like structure which is the primary component of the bacterial cell wall, is crucial to maintain cell integrity and shape. While most bacteria rely on penicillin binding proteins (PBPs) for crosslinking, some species also employ LD-transpeptidases (LDTs). Unlike PBPs, the essentiality and biological functions of LDTs remain largely unclear. The Hyphomicrobiales order of the Alphaproteobacteria, known for their polar growth, have PG which is unusually rich in LD-crosslinks, suggesting that LDTs may play a more significant role in PG synthesis in these bacteria. Here, we investigated LDTs in the plant pathogen Agrobacterium tumefaciens and found that LD-transpeptidation, resulting from at least one of 14 putative LDTs present in this bacterium, is essential for its survival. Notably, a mutant lacking a distinctive group of 7 LDTs which are broadly conserved among the Hyphomicrobiales exhibited reduced LD-crosslinking and tethering of PG to outer membrane \u03b2-barrel proteins. Consequently, this mutant suffered severe fitness loss and cell shape rounding, underscoring the critical role played by these Hyphomicrobiales-specific LDTs in maintaining cell wall integrity and promoting elongation. Tn-sequencing screens further revealed non-redundant functions for A. tumefaciens LDTs. Specifically, Hyphomicrobiales-specific LDTs exhibited synthetic genetic interactions with division and cell cycle proteins, and a single LDT from another group. Additionally, our findings demonstrate that strains lacking all LDTs except one displayed distinctive phenotypic profiles and genetic interactions. Collectively, our work emphasizes the critical role of LD-crosslinking in A. tumefaciens cell wall integrity and growth and provides insights into the functional specialization of these crosslinking activities.", "doi": "10.1371/journal.pgen.1011449", "pmid": "39432536", "labels": [], "xrefs": [{"db": "pmc", "key": "PMC11527210"}, {"db": "pii", "key": "PGENETICS-D-24-00706"}], "notes": [], "created": "2026-08-20T12:43:54.428Z", "modified": "2026-08-20T12:43:54.645Z"}]}