Armeniaspirols inhibit the AAA+ proteases ClpXP and ClpYQ leading to cell division arrest in Gram-positive bacteria

2021 ◽  
Author(s):  
Puneet Labana ◽  
Mark H. Dornan ◽  
Matthew Lafrenière ◽  
Tomasz L. Czarny ◽  
Eric D. Brown ◽  
...  
Keyword(s):  
Cell Division ◽  
Gram Positive ◽  
Gram Positive Bacteria

scholarly journals How Teichoic Acids Could Support a Periplasm in Gram-Positive Bacteria, and Let Cell Division Cheat Turgor Pressure

2021 ◽  
Vol 12 ◽  
Author(s):  
Harold P. Erickson
Keyword(s):  
Cell Division ◽  
Charge Density ◽  
Turgor Pressure ◽  
Support Pressure ◽  
Periplasmic Space ◽  
Gram Positive ◽  
Teichoic Acids ◽  
Gram Positive Bacteria ◽  
Peptidoglycan Cell Wall ◽  
Anionic Charge

The cytoplasm of bacteria is maintained at a higher osmolality than the growth medium, which generates a turgor pressure. The cell membrane (CM) cannot support a large turgor, so there are two possibilities for transferring the pressure to the peptidoglycan cell wall (PGW): (1) the CM could be pressed directly against the PGW, or (2) the CM could be separated from the PGW by a periplasmic space that is isoosmotic with the cytoplasm. There is strong evidence for gram-negative bacteria that a periplasm exists and is isoosmotic with the cytoplasm. No comparable studies have been done for gram-positive bacteria. Here I suggest that a periplasmic space is probably essential in order for the periplasmic proteins to function, including especially the PBPs that remodel the peptidoglycan wall. I then present a semi-quantitative analysis of how teichoic acids could support a periplasm that is isoosmotic with the cytoplasm. The fixed anionic charge density of teichoic acids in the periplasm is ∼0.5 M, which would bring in ∼0.5 M Na+ neutralizing ions. This approximately balances the excess osmolality of the cytoplasm that would produce a turgor pressure of 19 atm. The 0.5 M fixed charge density is similar to that of proteoglycans in articular cartilage, suggesting a comparability ability to support pressure. An isoosmotic periplasm would be especially important for cell division, since it would allow CM constriction and PGW synthesis to avoid turgor pressure.

scholarly journals Active Stable Maintenance Functions in Low Copy-Number Plasmids of Gram-positive Bacteria. I. Partition Systems

2013 ◽  
Vol 62 (1) ◽  
pp. 3-16 ◽  
Author(s):  
MICHAŁ DMOWSKI ◽  
GRAŻYNA JAGURA-BURDZY
Keyword(s):  
Cell Division ◽  
Copy Number ◽  
Significant Contribution ◽  
Bacterial Cell Division ◽  
Gram Positive ◽  
Gram Positive Bacteria ◽  
Daughter Cells ◽  
Low Copy Number ◽  
Random Segregation ◽  
Stable Maintenance

Low copy number plasmids cannot rely on the random segregation during bacterial cell division. To be stably maintained in the population they evolved two types of mechanisms (i) partition systems (PAR) that actively separate replicated plasmid molecules to the daughter cells and (ii) toxin-andidote systems (TA) that act after cell division to kill plasmid-less cells. Our knowledge of partition systems has been based mainly on analysis of plasmids from Gram-negative bacteria. Now, numerous partition systems of plasmids from Gram-positive bacteria have also been characterized and make significant contribution to our understanding of these mechanisms.

scholarly journals ¡vIVA la DivIVA!

2019 ◽  
Vol 201 (21) ◽  
Author(s):  
Lauren R. Hammond ◽  
Maria L. White ◽  
Prahathees J. Eswara
Keyword(s):  
Cell Division ◽  
Chromosome Segregation ◽  
Parental Cell ◽  
Model Organisms ◽  
Posttranslational Regulation ◽  
Bacterial Cell Division ◽  
Gram Positive ◽  
Content Type ◽  
Gram Positive Bacteria ◽  
Division Cell

ABSTRACT Reproduction in the bacterial kingdom predominantly occurs through binary fission—a process in which one parental cell is divided into two similarly sized daughter cells. How cell division, in conjunction with cell elongation and chromosome segregation, is orchestrated by a multitude of proteins has been an active area of research spanning the past few decades. Together, the monumental endeavors of multiple laboratories have identified several cell division and cell shape regulators as well as their underlying regulatory mechanisms in rod-shaped Escherichia coli and Bacillus subtilis, which serve as model organisms for Gram-negative and Gram-positive bacteria, respectively. Yet our understanding of bacterial cell division and morphology regulation is far from complete, especially in noncanonical and non-rod-shaped organisms. In this review, we focus on two proteins that are highly conserved in Gram-positive organisms, DivIVA and its homolog GpsB, and attempt to summarize the recent advances in this area of research and discuss their various roles in cell division, cell growth, and chromosome segregation in addition to their interactome and posttranslational regulation.

scholarly journals Protein Interactomes Identify Distinct Pathways for Streptococcus mutans YidC1 and YidC2 Membrane Protein Insertases

2020 ◽  
Author(s):  
Patricia Lara Vasquez ◽  
Surabhi Mishra ◽  
Senthil K. Kuppuswamy ◽  
Paula J. Crowley ◽  
L. Jeannine Brady
Keyword(s):  
Cell Division ◽  
Membrane Proteins ◽  
Streptococcus Mutans ◽  
Physiological Role ◽  
Integral Membrane Proteins ◽  
Environmental Niche ◽  
Gram Positive ◽  
Bacterial Membranes ◽  
Gram Positive Bacteria ◽  
Ms Analysis

AbstractVirulence properties of cariogenic Streptococcus mutans depend on integral membrane proteins. Bacterial protein trafficking involves the co-translational signal recognition particle (SRP) pathway components Ffh and FtsY, the SecY translocon, and membrane-localized YidC chaperone/insertases. Unlike Escherichia coli, S. mutans survives loss of the SRP pathway. In addition, S. mutans has two yidC paralogs. The ΔyidC2 phenotype largely parallels that of Δffh and ΔftsY while the ΔyidC1 phenotype is less severe. This study defined YidC1 and YidC2 interactomes to identify their respective functions alone and in concert with the SRP, ribosome, and/or Sec translocon. A chemical cross-linking approach was employed, whereby whole cell lysates were treated with formaldehyde followed by Western blotting using anti-Ffh, FtsY, YidC1 or YidC2 antibodies and mass spectrometry (MS) analysis of gel-shifted bands. Cross-linked lysates from WT and ΔyidC2 strains were also reacted with anti-YidC2 antibodies coupled to magnetic Dynabeads™, with co-captured proteins identified by MS. Additionally, C-terminal tails of YidC1 and YidC2 were engineered as glutathione-S-transferase fusion proteins and subjected to 2D Difference Gel Electrophoresis and MS analysis after being reacted with non-cross-linked lysates. Results indicate that YidC2 works in concert with the SRP-pathway, while YidC1 works in concert with the SecY translocon independently of the SRP. In addition, YidC1 and/or YidC2 can act alone in the insertion of a limited number of small integral membrane proteins. The YidC2-SRP and YidC1/SecY pathways appear to function as part of an integrated machinery that couples translation and transport with cell division, as well as transcription and DNA replication.ImportanceStreptococcus mutans is a prevalent oral pathogen and causative agent of tooth decay. Many proteins that enable this bacterium to thrive in its environmental niche, and cause disease, are embedded in its cytoplasmic membrane. The machinery that transports proteins into bacterial membranes differs between Gram-negative and Gram-positive organisms. One important difference is the presence of multiple YidC paralogs in Gram-positive bacteria. Characterization of a protein’s interactome can help define its physiological role. Herein, we characterized the interactomes of S. mutans YidC1 and YidC2. Results indicate that YidC1 and YidC2 have individualized functions in separate membrane insertion pathways, and suggest putative substrates of the respective pathways. Furthermore, S. mutans membrane transport proteins appear as part of a larger network of proteins involved in replication, transcription, translation, and cell division/cell shape. This information contributes to our understanding of protein transport in Gram-positive bacteria in general, and informs our understanding of S. mutans pathogenesis.

Mesosome-like Structures in a Blue-green Alga, Phormidium Luridum

1970 ◽  
Vol 28 ◽  
pp. 180-181
Author(s):  
Mercedes R. Edwards
Keyword(s):  
Plasma Membrane ◽  
Cell Division ◽  
Dna Replication ◽  
Green Alga ◽  
Photosynthetic Bacteria ◽  
Blue Green Alga ◽  
Gram Positive ◽  
Gram Positive Bacteria ◽  
Lamellar Structures ◽  
Septum Formation

The invagination of the plasma membrane (plasmalemma) to form vesicular or lamellar structures, usually called mesosomes (l) or plasmalemmosomes (2), has been extensively documented in bacteria (3) and more recently also in lower eucaryotes (e.g., the fungi, 4). Such structures have “been implicated in septum formation (i.e., cell division of gram-positive bacteria), in respiratory reactions, and in DNA replication.In photosynthetic bacteria, such as Rhodospirilium rubrum, vesicular structures derived from the plasma membrane were shown by Drews and Giesbrecht (5) to give rise to thylakoids (photosynthetic vesicles or chromatophores). Continuation between the plasma and thylakoidal membranes is readily seen in R. rubrum (6).

scholarly journals Dynamic Distribution of the SecA and SecY Translocase Subunits and Septal Localization of the HtrA Surface Chaperone/Protease during Streptococcus pneumoniae D39 Cell Division

mBio ◽  
2011 ◽  
Vol 2 (5) ◽  
Author(s):  
Ho-Ching Tiffany Tsui ◽  
Susan K. Keen ◽  
Lok-To Sham ◽  
Kyle J. Wayne ◽  
Malcolm E. Winkler
Keyword(s):  
Cell Division ◽  
Streptococcus Pneumoniae ◽  
Stationary Phase ◽  
Streptococcus Pyogenes ◽  
Phospholipid Content ◽  
Gram Positive ◽  
General Role ◽  
Content Type ◽  
Gram Positive Bacteria ◽  
Dividing Cells

ABSTRACT The Sec translocase pathway is the major route for protein transport across and into the cytoplasmic membrane of bacteria. Previous studies reported that the SecA translocase ATP-binding subunit and the cell surface HtrA protease/chaperone formed a single microdomain, termed “ExPortal,” in some species of ellipsoidal (ovococcus) Gram-positive bacteria, including Streptococcus pyogenes. To investigate the generality of microdomain formation, we determined the distribution of SecA and SecY by immunofluorescent microscopy in Streptococcus pneumoniae (pneumococcus), which is an ovococcus species evolutionarily distant from S. pyogenes. In the majority (≥75%) of exponentially growing cells, S. pneumoniae SecA (SecA Spn ) and SecY Spn located dynamically in cells at different stages of division. In early divisional cells, both Sec subunits concentrated at equators, which are future sites of constriction. Further along in division, SecA Spn and SecY Spn remained localized at mid-cell septa. In late divisional cells, both Sec subunits were hemispherically distributed in the regions between septa and the future equators of dividing cells. In contrast, the HtrA Spn homologue localized to the equators and septa of most (>90%) dividing cells, whereas the SrtA Spn sortase located over the surface of cells in no discernable pattern. This dynamic pattern of Sec distribution was not perturbed by the absence of flotillin family proteins, but was largely absent in most cells in early stationary phase and in ∆cls mutants lacking cardiolipin synthase. These results do not support the existence of an ExPortal microdomain in S. pneumoniae. Instead, the localization of the pneumococcal Sec translocase depends on the stage of cell division and anionic phospholipid content. IMPORTANCE Two patterns of Sec translocase distribution, an ExPortal microdomain in certain ovococcus-shaped species like Streptococcus pyogenes and a spiral pattern in rod-shaped species like Bacillus subtilis, have been reported for Gram-positive bacteria. This study provides evidence for a third pattern of Sec localization in the ovococcus human pathogen Streptococcus pneumoniae. The SecA motor and SecY channel subunits of the Sec translocase localize dynamically to different places in the mid-cell region during the division cycle of exponentially growing, but not stationary-phase, S. pneumoniae. Unexpectedly, the S. pneumoniae HtrA (HtrA Spn ) protease/chaperone principally localizes to cell equators and division septa. The coincident localization of SecA Spn , SecY Spn , and HtrA Spn to regions of peptidoglycan (PG) biosynthesis in unstressed, growing cells suggests that the pneumococcal Sec translocase directs assembly of the PG biosynthesis apparatus to regions where it is needed during division and that HtrA Spn may play a general role in quality control of proteins exported by the Sec translocase.

scholarly journals The Cell Wall Polymer Lipoteichoic Acid Becomes Nonessential inStaphylococcus aureusCells Lacking the ClpX Chaperone

mBio ◽  
2016 ◽  
Vol 7 (4) ◽  
Author(s):  
Kristoffer T. Bæk ◽  
Lisa Bowman ◽  
Charlotte Millership ◽  
Mia Dupont Søgaard ◽  
Volkhard Kaever ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Cell Wall ◽  
Cell Division ◽  
Lipoteichoic Acid ◽  
Growth Defect ◽  
Gram Positive ◽  
Functional Connection ◽  
Antibiotic Resistant ◽  
Gram Positive Bacteria ◽  
Autolytic Activity

ABSTRACTLipoteichoic acid (LTA) is an important cell wall component of Gram-positive bacteria and a promising target for the development of vaccines and antimicrobial compounds againstStaphylococcus aureus. Here we demonstrate that mutations in the conditionally essentialltaS(LTA synthase) gene arise spontaneously in anS. aureusmutant lacking the ClpX chaperone. A wide variety ofltaSmutations were selected, and among these, a substantial portion resulted in premature stop codons and other changes predicted to abolish LtaS synthesis. Consistent with this assumption, theclpX ltaSdouble mutants did not produce LTA, and genetic analyses confirmed that LTA becomes nonessential in the absence of the ClpX chaperone. In fact, inactivation ofltaSalleviated the severe growth defect conferred by theclpXdeletion. Microscopic analyses showed that the absence of ClpX partly alleviates the septum placement defects of an LTA-depleted strain, while other phenotypes typical of LTA-negativeS. aureusmutants, including increased cell size and decreased autolytic activity, are retained. In conclusion, our results indicate that LTA has an essential role in septum placement that can be bypassed by inactivating the ClpX chaperone.IMPORTANCELipoteichoic acid is an essential component of theStaphylococcus aureuscell envelope and an attractive target for the development of vaccines and antimicrobials directed against antibiotic-resistant Gram-positive bacteria such as methicillin-resistantS. aureusand vancomycin-resistant enterococci. In this study, we showed that the lipoteichoic acid polymer is essential for growth ofS. aureusonly as long as the ClpX chaperone is present in the cell. Our results indicate that lipoteichoic acid and ClpX play opposite roles in a pathway that controls two key cell division processes inS. aureus, namely, septum formation and autolytic activity. The discovery of a novel functional connection in the genetic network that controls cell division inS. aureusmay expand the repertoire of possible strategies to identify compounds or compound combinations that kill antibiotic-resistantS. aureus.

scholarly journals Armeniaspirols inhibit the AAA+ proteases ClpXP and ClpYQ leading to cell division arrest in Gram-positive bacteria

2019 ◽  
Author(s):  
Puneet Labana ◽  
Mark H. Dornan ◽  
Matthew Lafrenière ◽  
Tomasz L. Czarny ◽  
Eric D. Brown ◽  
...  
Keyword(s):  
Cell Division ◽  
Mechanism Of Action ◽  
Modern Medicine ◽  
Resistant Bacteria ◽  
Gram Positive ◽  
Biologically Relevant ◽  
Gram Positive Bacteria ◽  
Drug Resistant Bacteria ◽  
New Antibiotics ◽  
Virulence Target

ABSTRACTMulti-drug resistant bacteria present an urgent threat to modern medicine, creating a desperate need for the discovery of antibiotics with new modes of action. Natural products whose unique highly diverse structures have been shaped by evolution to possess biologically relevant activity are an ideal discovery ground for new antibiotics with new mechanisms of action. In this study we elucidate the mechanism of action of the Gram-positive antibiotic armeniaspirol, a compound for which resistant bacteria could not be selected for. We show that armeniaspirol inhibits the ATP-dependent proteases ClpXP and ClpYQ in biochemical assays and in the Gram-positive bacteria Bacillus subtilis. We then show that this activity dysregulates key proteins involved in the divisome and elongasome including FtsZ, DivIVA, and MreB all of which are known to inhibit cell division when upregulated. Inhibition of ClpXP and ClpYQ leading to dysregulation of the divisome and elongasome represents a new mechanism of action and armeniaspirol is the first known natural product inhibitor of the coveted anti-virulence target ClpP. Thus armeniaspirol is the lead compound for a promising new class of antibiotics with a unique pharmacology and a novel mechanism for combating antimicrobial resistance, making it a highly promising candidate for further development.

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