Loss of PopZ<sub><italic toggle="yes">At</italic></sub> activity in <italic toggle="yes">Agrobacterium tumefaciens</italic> by Deletion or Depletion Leads to Multiple Growth Poles, Minicells, and Growth Defects
ABSTRACT Agrobacterium tumefaciens grows by addition of peptidoglycan (PG) at one pole of the bacterium. During the cell cycle, the cell needs to maintain two different developmental programs, one at the growth pole and another at the inert old pole. Proteins involved in this process are not yet wel...
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| Format: | Article |
| Language: | English |
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American Society for Microbiology
2017-12-01
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| Series: | mBio |
| Subjects: | |
| Online Access: | https://journals.asm.org/doi/10.1128/mBio.01881-17 |
| _version_ | 1818844445713367040 |
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| author | Romain Grangeon John Zupan Yeonji Jeon Patricia C. Zambryski |
| author_facet | Romain Grangeon John Zupan Yeonji Jeon Patricia C. Zambryski |
| author_sort | Romain Grangeon |
| collection | DOAJ |
| description | ABSTRACT Agrobacterium tumefaciens grows by addition of peptidoglycan (PG) at one pole of the bacterium. During the cell cycle, the cell needs to maintain two different developmental programs, one at the growth pole and another at the inert old pole. Proteins involved in this process are not yet well characterized. To further characterize the role of pole-organizing protein A. tumefaciens PopZ (PopZAt), we created deletions of the five PopZAt domains and assayed their localization. In addition, we created a popZAt deletion strain (ΔpopZAt) that exhibited growth and cell division defects with ectopic growth poles and minicells, but the strain is unstable. To overcome the genetic instability, we created an inducible PopZAt strain by replacing the native ribosome binding site with a riboswitch. Cultivated in a medium without the inducer theophylline, the cells look like ΔpopZAt cells, with a branching and minicell phenotype. Adding theophylline restores the wild-type (WT) cell shape. Localization experiments in the depleted strain showed that the domain enriched in proline, aspartate, and glutamate likely functions in growth pole targeting. Helical domains H3 and H4 together also mediate polar localization, but only in the presence of the WT protein, suggesting that the H3 and H4 domains multimerize with WT PopZAt, to stabilize growth pole accumulation of PopZAt. IMPORTANCE Agrobacterium tumefaciens is a rod-shaped bacterium that grows by addition of PG at only one pole. The factors involved in maintaining cell asymmetry during the cell cycle with an inert old pole and a growing new pole are not well understood. Here we investigate the role of PopZAt, a homologue of Caulobacter crescentus PopZ (PopZCc), a protein essential in many aspects of pole identity in C. crescentus. We report that the loss of PopZAt leads to the appearance of branching cells, minicells, and overall growth defects. As many plant and animal pathogens also employ polar growth, understanding this process in A. tumefaciens may lead to the development of new strategies to prevent the proliferation of these pathogens. In addition, studies of A. tumefaciens will provide new insights into the evolution of the genetic networks that regulate bacterial polar growth and cell division. |
| first_indexed | 2024-12-19T05:13:53Z |
| format | Article |
| id | doaj.art-c804e9c3a8de4db5818d80798d391917 |
| institution | Directory Open Access Journal |
| issn | 2150-7511 |
| language | English |
| last_indexed | 2024-12-19T05:13:53Z |
| publishDate | 2017-12-01 |
| publisher | American Society for Microbiology |
| record_format | Article |
| series | mBio |
| spelling | doaj.art-c804e9c3a8de4db5818d80798d3919172022-12-21T20:34:44ZengAmerican Society for MicrobiologymBio2150-75112017-12-018610.1128/mBio.01881-17Loss of PopZ<sub><italic toggle="yes">At</italic></sub> activity in <italic toggle="yes">Agrobacterium tumefaciens</italic> by Deletion or Depletion Leads to Multiple Growth Poles, Minicells, and Growth DefectsRomain Grangeon0John Zupan1Yeonji Jeon2Patricia C. Zambryski3Department of Plant and Microbial Biology, University of California Berkeley, Berkeley, California, USADepartment of Plant and Microbial Biology, University of California Berkeley, Berkeley, California, USADepartment of Plant and Microbial Biology, University of California Berkeley, Berkeley, California, USADepartment of Plant and Microbial Biology, University of California Berkeley, Berkeley, California, USAABSTRACT Agrobacterium tumefaciens grows by addition of peptidoglycan (PG) at one pole of the bacterium. During the cell cycle, the cell needs to maintain two different developmental programs, one at the growth pole and another at the inert old pole. Proteins involved in this process are not yet well characterized. To further characterize the role of pole-organizing protein A. tumefaciens PopZ (PopZAt), we created deletions of the five PopZAt domains and assayed their localization. In addition, we created a popZAt deletion strain (ΔpopZAt) that exhibited growth and cell division defects with ectopic growth poles and minicells, but the strain is unstable. To overcome the genetic instability, we created an inducible PopZAt strain by replacing the native ribosome binding site with a riboswitch. Cultivated in a medium without the inducer theophylline, the cells look like ΔpopZAt cells, with a branching and minicell phenotype. Adding theophylline restores the wild-type (WT) cell shape. Localization experiments in the depleted strain showed that the domain enriched in proline, aspartate, and glutamate likely functions in growth pole targeting. Helical domains H3 and H4 together also mediate polar localization, but only in the presence of the WT protein, suggesting that the H3 and H4 domains multimerize with WT PopZAt, to stabilize growth pole accumulation of PopZAt. IMPORTANCE Agrobacterium tumefaciens is a rod-shaped bacterium that grows by addition of PG at only one pole. The factors involved in maintaining cell asymmetry during the cell cycle with an inert old pole and a growing new pole are not well understood. Here we investigate the role of PopZAt, a homologue of Caulobacter crescentus PopZ (PopZCc), a protein essential in many aspects of pole identity in C. crescentus. We report that the loss of PopZAt leads to the appearance of branching cells, minicells, and overall growth defects. As many plant and animal pathogens also employ polar growth, understanding this process in A. tumefaciens may lead to the development of new strategies to prevent the proliferation of these pathogens. In addition, studies of A. tumefaciens will provide new insights into the evolution of the genetic networks that regulate bacterial polar growth and cell division.https://journals.asm.org/doi/10.1128/mBio.01881-17Agrobacterium tumefaciensPopZpolar growthriboswitch |
| spellingShingle | Romain Grangeon John Zupan Yeonji Jeon Patricia C. Zambryski Loss of PopZ<sub><italic toggle="yes">At</italic></sub> activity in <italic toggle="yes">Agrobacterium tumefaciens</italic> by Deletion or Depletion Leads to Multiple Growth Poles, Minicells, and Growth Defects mBio Agrobacterium tumefaciens PopZ polar growth riboswitch |
| title | Loss of PopZ<sub><italic toggle="yes">At</italic></sub> activity in <italic toggle="yes">Agrobacterium tumefaciens</italic> by Deletion or Depletion Leads to Multiple Growth Poles, Minicells, and Growth Defects |
| title_full | Loss of PopZ<sub><italic toggle="yes">At</italic></sub> activity in <italic toggle="yes">Agrobacterium tumefaciens</italic> by Deletion or Depletion Leads to Multiple Growth Poles, Minicells, and Growth Defects |
| title_fullStr | Loss of PopZ<sub><italic toggle="yes">At</italic></sub> activity in <italic toggle="yes">Agrobacterium tumefaciens</italic> by Deletion or Depletion Leads to Multiple Growth Poles, Minicells, and Growth Defects |
| title_full_unstemmed | Loss of PopZ<sub><italic toggle="yes">At</italic></sub> activity in <italic toggle="yes">Agrobacterium tumefaciens</italic> by Deletion or Depletion Leads to Multiple Growth Poles, Minicells, and Growth Defects |
| title_short | Loss of PopZ<sub><italic toggle="yes">At</italic></sub> activity in <italic toggle="yes">Agrobacterium tumefaciens</italic> by Deletion or Depletion Leads to Multiple Growth Poles, Minicells, and Growth Defects |
| title_sort | loss of popz sub italic toggle yes at italic sub activity in italic toggle yes agrobacterium tumefaciens italic by deletion or depletion leads to multiple growth poles minicells and growth defects |
| topic | Agrobacterium tumefaciens PopZ polar growth riboswitch |
| url | https://journals.asm.org/doi/10.1128/mBio.01881-17 |
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