E. coli Transports Aggregated Proteins to the Poles by a Specific and Energy-Dependent Process

Rokney, Assaf; Shagan, Merav; Kessel, Martin; Smith, Yoav; Rosenshine, Ilan; Oppenheim, Amos B.

doi:10.1016/j.jmb.2009.07.009

Cited by 96 publications

(115 citation statements)

References 33 publications

Supporting

Mentioning

104

Contrasting

Order By: Relevance

“…Because soluble GFP has no affinity for the cell pole, its residence time at this location is limited by the rate of diffusion. To obtain a lower boundary for the rate of polar dissociation, we performed the FLIP assay on IcsA 507-620 -mChy, a protein that forms aggregates in E. coli (24). We expected that individual proteins within an aggregate would undergo very little exchange with the cytoplasm, and this was supported by our analysis.…”

Section: Popz Is Similar To Intrinsically Disordered Hub Proteins In mentioning

confidence: 62%

Caulobacter PopZ forms an intrinsically disordered hub in organizing bacterial cell poles

Holmes

Follett

Hai-bi

et al. 2016

Proc. Natl. Acad. Sci. U.S.A.

158

View full text Add to dashboard Cite

Despite their relative simplicity, bacteria have complex anatomy at the subcellular level. At the cell poles of Caulobacter crescentus, a 177-amino acid (aa) protein called PopZ self-assembles into 3D polymeric superstructures. Remarkably, we find that this assemblage interacts directly with at least eight different proteins, which are involved in cell cycle regulation and chromosome segregation. The binding determinants within PopZ include 24 aa at the N terminus, a 32-aa region near the C-terminal homo-oligomeric assembly domain, and portions of an intervening linker region. Together, the N-terminal 133 aa of PopZ are sufficient for interacting with all binding partners, even in the absence of homooligomeric assembly. Structural analysis of this region revealed that it is intrinsically disordered, similar to p53 and other hub proteins that organize complex signaling networks in eukaryotic cells. Through live-cell photobleaching, we find rapid binding kinetics between PopZ and its partners, suggesting many pole-localized proteins become concentrated at cell poles through rapid cycles of binding and unbinding within the PopZ scaffold. We conclude that some bacteria, similar to their eukaryotic counterparts, use intrinsically disordered hub proteins for network assembly and subcellular organization.PopZ | intrinsically disordered protein | bacteria | Caulobacter | hub protein

show abstract

Section: Popz Is Similar To Intrinsically Disordered Hub Proteins In mentioning

confidence: 62%

Caulobacter PopZ forms an intrinsically disordered hub in organizing bacterial cell poles

Holmes

Follett

Hai-bi

et al. 2016

Proc. Natl. Acad. Sci. U.S.A.

158

View full text Add to dashboard Cite

show abstract

“…Restriction of aggregates to the pole was also observed during treatment with substances disrupting the protein motive force, suggesting an energy independent process of aggregation [20]. Energy-independent polar localization was also confirmed by others [30] but also convincing opposite results were obtained [15]. Thus, it is not absolutely clear if active ATP-dependent transport of smaller particles is required or if the fluidizing properties of active metabolism are responsible for the polar preference of protein aggregates [16].…”

Section: Cellular Formation Of Ibsmentioning

confidence: 86%

“…There is still controversy whether IB formation is a passive process only depending on physically interacting protein chains or if it is an energy-driven process that requires active involvement of the cell [15][16][17].…”

Section: Cellular Formation Of Ibsmentioning

confidence: 99%

“…IBs and aggregation foci are not only found at the polar sites but also in mid-cells presumably at the place of future septation sites [20,30,31]. The major disaggregating chaperones (DnaK, ClpB) also co-localize at the poles [20] and are required for disaggregation of polar aggregates [15]. Polar distribution of IBs or damaged proteins may reflect an evolutional benefit compared to unbiased dilution of misfolded and aggregated proteins as continued cell division leads to rejuvenation [20,31].…”

Section: Cellular Formation Of Ibsmentioning

confidence: 99%

See 1 more Smart Citation

Bacterial Inclusion Bodies: Discovering Their Better Half

Rinas

García‐Fruitós

Corchero

et al. 2017

Trends in Biochemical Sciences

141

123

View full text Add to dashboard Cite

Bacterial inclusion bodies are functional, non-toxic amyloids occurring in recombinant bacteria that show analogies with secretory granules of the mammalian endocrine system. The scientific interest in these mesoscale protein aggregates has been historically masked by their status as a hurdle in recombinant protein production.However, insights into their molecular organization and the progressive understanding on how the cell handles the quality of recombinant polypeptides have stimulated the interest on inclusion bodies and opened ways for their usability in diverse technological fields. The engineering and tailoring of inclusion bodies as functional protein particles for materials science and biomedicine is a good example of how formerly undesired bacterial by-products can be re-discovered as promising functional materials for a broad spectrum of applications.-2 - BACKGROUND

show abstract

“…The tight localization of Cas2 at the poles of the E. coli cells is in good agreement with the preferred point of bacteriophage entry; thus it is tempting to speculate that Cas2 localization plays a role in phage resistance. It has recently been reported that protein aggregates can also be accumulated at the poles of bacterial cells (37), so further analysis is needed to prove the in vivo relevance of this observed localization of overexpressed Cas2. Single molecules with localization precision (FWHM) worse than 100 nm are filtered out in data analysis.…”

Section: Resultsmentioning

confidence: 99%

Near-isotropic 3D optical nanoscopy with photon-limited chromophores

Tang

Akerboom

Vaziri

et al. 2010

Proc. Natl. Acad. Sci. U.S.A.

View full text Add to dashboard Cite

Imaging approaches based on single molecule localization break the diffraction barrier of conventional fluorescence microscopy, allowing for bioimaging with nanometer resolution. It remains a challenge, however, to precisely localize photon-limited single molecules in 3D. We have developed a new localization-based imaging technique achieving almost isotropic subdiffraction resolution in 3D. A tilted mirror is used to generate a side view in addition to the front view of activated single emitters, allowing their 3D localization to be precisely determined for superresolution imaging. Because both front and side views are in focus, this method is able to efficiently collect emitted photons. The technique is simple to implement on a commercial fluorescence microscope, and especially suitable for biological samples with photon-limited chromophores such as endogenously expressed photoactivatable fluorescent proteins. Moreover, this method is relatively resistant to optical aberration, as it requires only centroid determination for localization analysis. Here we demonstrate the application of this method to 3D imaging of bacterial protein distribution and neuron dendritic morphology with subdiffraction resolution.3D bioimaging | nanoimaging | bacterial imaging | neuron imaging | biophotonics F luorescence microscopy allows the observation of biological samples in a highly sensitive, selective, and relatively noninvasive fashion. Moreover, fluorescence imaging tools can probe deeply into tissues to obtain volume images without physically isolating different sections. However, traditional fluorescence microscopy suffers from diffraction-limited resolution, far larger than actual molecular sizes. Recent development of two different superresolution (SR) fluorescence imaging methods has broken the diffraction limit and enables direct optical observation of biological features near molecular scales. One approach is to create a subdiffraction excitation pattern by stimulated emission depletion (1, 2) or structured illumination (3, 4), and the other approach is based on single molecule localization (5-9). An essential part of the single molecule localization methods involves centroid fitting of serial single molecule images at the detection plane in order to determine the lateral localization of each fluorescent molecule with precision limited not by diffraction, but mainly by its number of emitted photons. A superresolution 2D image of the sample can then be rendered by overlapping all single molecule localizations from all image frames. This principle of localization has also been applied to single particle tracking (10)(11)(12)(13)(14).Single molecule-based superresolution microscopy requires individual chromophores to be turned "on" and "off" sequentially, either by photoswitching or by other stochastic photophysical processes. Compared to synthetic photoswitchable probes, photoactivatable fluorescent proteins (PA-FPs) (15-20) are superior in many regards: PA-FPs can be genetically fused to target proteins and endogenously...

show abstract

E. coli Transports Aggregated Proteins to the Poles by a Specific and Energy-Dependent Process

Cited by 96 publications

References 33 publications

Caulobacter PopZ forms an intrinsically disordered hub in organizing bacterial cell poles

Caulobacter PopZ forms an intrinsically disordered hub in organizing bacterial cell poles

Bacterial Inclusion Bodies: Discovering Their Better Half

Near-isotropic 3D optical nanoscopy with photon-limited chromophores

Contact Info

Product

Resources

About