Assembly mechanisms of the bacterial cytoskeletal protein FilP

Javadi, Ala; Söderholm, Niklas; Olofsson, Annelie; Flärdh, Klas; Sandblad, Linda

doi:10.26508/lsa.201800290

Cited by 8 publications

(9 citation statements)

References 52 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…We predict that the layer represents a putative polarisome and thus, the observed structure likely represents a complex of DivIVA and Scy (Holmes et al, 2013). While purified FilP formed striated bundles in vitro when imaged with negative staining EM (Soderholm et al, 2018;Javadi et al, 2019), we did not observe such structures in our tomograms, suggesting that FilP may adopt alternate conformations under native conditions or in association with other proteins. Additional filaments were occasionally observed in the cytoplasm, along the length of the vegetative hyphae and near hyphal tips (Supplementary Figure S1 and Supplementary Movie S2).…”

Section: Features Of Vegetative Hyphaementioning

confidence: 65%

Ultrastructure of Exospore Formation in Streptomyces Revealed by Cryo-Electron Tomography

Sexton

Tocheva

2020

Front. Microbiol.

View full text Add to dashboard Cite

Many bacteria form spores in response to adverse environmental conditions. Several sporulation pathways have evolved independently and occur through distinctive mechanisms. Here, using cryo-electron tomography (cryo-ET), we examine all stages of growth and exospore formation in the model organism Streptomyces albus. Our data reveal the native ultrastructure of vegetative hyphae, including the likely structures of the polarisome and cytoskeletal filaments. In addition, we observed septal junctions in vegetative septa, predicted to be involved in protein and DNA translocation between neighboring cells. During sporulation, the cell envelope undergoes dramatic remodeling, including the formation of a spore wall and two protective proteinaceous layers. Mature spores reveal the presence of a continuous spore coat and an irregular rodlet sheet. Together, these results provide an unprecedented examination of the ultrastructure in Streptomyces and further our understanding of the structural complexity of exospore formation.

show abstract

Section: Features Of Vegetative Hyphaementioning

confidence: 65%

Ultrastructure of Exospore Formation in Streptomyces Revealed by Cryo-Electron Tomography

Sexton

Tocheva

2020

Front. Microbiol.

View full text Add to dashboard Cite

show abstract

“…The assembly of CCRPs into filaments in vitro was tested by fluorescence microscopy using the NHS-Fluorescein dye, which was previously successfully used to visualize in vitro FtsZ protein filaments 36 . Similar to previous investigations of filament-froming CCRPs 8, 9, 20 , we purified His 6 -tagged CCRPs by Ni-NTA affinity chromatography under denaturing conditions and renatured them by dialysis followed by NHS-fluorescein staining. We note that the His 6 -tag has previously been shown to have no impact on the in vitro polymerization properties of the CCRP FilP 20 .…”

Section: Resultsmentioning

confidence: 86%

“…Similar to previous investigations of filament-froming CCRPs 8, 9, 20 , we purified His 6 -tagged CCRPs by Ni-NTA affinity chromatography under denaturing conditions and renatured them by dialysis followed by NHS-fluorescein staining. We note that the His 6 -tag has previously been shown to have no impact on the in vitro polymerization properties of the CCRP FilP 20 . As a positive control for our approach we used crescentin.…”

Section: Resultsmentioning

confidence: 86%

“…This characteristic polar growth mode is organized by a cytoskeletal network of at least three CCRPs - DivIVA, Scy and FilP – that form the polarisome 9 . Two of those, FilP and Scy, self-assemble into filaments in vitro 9, 11, 20 thereby fulfilling a major criterion of IF-like cytoskeletal proteins 14 . In vivo , however, Scy does not form filaments and instead acuumulates as foci at future branching points 9 , while FilP localizes as gradient-like caudates at the hyphael tips 21 instead of forming distinct filaments as observed for the CCRP crescentin from Caulobacter crescentus 8 .…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Two novel heteropolymer-forming proteins maintain multicellular shape of the cyanobacteriumAnabaenasp. PCC 7120

Springstein

Nürnberg²,

Kieninger

et al. 2019

Preprint

View full text Add to dashboard Cite

23The determinants of bacterial cell shape are extensively studied in unicellular forms. 24Nonetheless, the mechanisms that shape bacterial multicellular forms remain understudied. 25Here we study coiled-coil rich proteins (CCRPs) in the multicellular cyanobacterium Anabaena 26 sp. PCC 7120 (hereafter Anabaena). Our results reveal two CCPRs, termed LfiA and LfiB (for 27 linear filament), which assemble into a heteropolymer that traverses the longitudinal cell axis. 28Two additional CCRPs, CypS (for cyanobacterial polar scaffold) and CeaR (for cyanobacterial 29 elongasome activity regulator), form a polar proteinaceous scaffold and regulate MreB activity, 30 respectively. Deletion mutants of these CCRPs are characterized by impaired filament shape 31 and decreased viability. Our results indicate that the four CCRPs form a proteinaceous network 32 that stabilizes the Anabaena multicellular filament. We propose that this cytoskeletal network 33 is essential for the manifestation of the linear filament phenotype in Anabaena. 34 (a multi-enzyme complex), is a regulator of longitudinal PG biogenesis, and thus it plays a 49 crucial role in the adaption to different environments and prokaryotic multicellularity. 50The key hallmarks of permanent bacterial multicellularity are morphological 51 differentiation and a well-defined and reproducible shape, termed patterned multicellularity 3 . 52Unlike biofilms, patterned multicellular structures are the result of either coordinated swarming 53 or developmental aggregation behavior as in myxobacteria 9 . Additional factors include cell 54 division, proliferation and cell differentiation as in sporulating actinomycetes 10 and 55 cyanobacterial filaments 11,12 . In myxobacteria as well as in actinomycetes, it has been shown 56 that patterned multicellular traits are dependent on the coordinated function of different coiled-57 coil-rich proteins (CCRPs). Reminiscent of eukaryotic intermediate filaments (IFs) 13,14 , many 58 bacterial CCRPs were shown to perform analogous cytoskeletal functions through their ability 59 to self-assemble into distinct filaments in vitro and in vivo [15][16][17][18][19] . Unlike FtsZ or MreB 20,21 , 60 bacterial IF-like CCRPs do not require any additional co-factors for polymerization in vitro 22 . 61For example, in Myxococcus xanthus, the coordinated swarming and aggregation into fruiting 62 bodies is mediated by its gliding motility 23 , which strictly depends on the filament-forming 63 CCRP AglZ 24 . AglZ is organized in a large multi-protein complex that governs gliding motility 64 in synergy with MreB, which still retained its PG synthesis function but was also co-opted for 65 gliding motility in M. xanthus [25][26][27][28] . Actinobacteria, such as Streptomyces species, grow by 66 building new cell wall (i.e. PG) only at the cell poles, independent of MreB 29,30 , which is 67 strikingly different from how most other bacteria grow 31 . This characteristic polar growth mode 68 is organized by a cytoskeletal network of at least three CCRPs -DivIVA...

show abstract

“…This characteristic polar growth mode is organized by a cytoskeletal network of at least three CCRPs – DivIVA, Scy and FilP – that directly interact with each other to form the polarisome [18]. FilP and Scy independently self‐assemble into filaments in vitro [18,25], thereby fulfilling major IF‐like criteria [1]. In vivo , however, Scy does not form filaments and instead accumulates as foci at future branching points [18], while FilP localizes as gradient‐like caudates at the hyphal tips [26], instead of forming distinct filaments as observed for Crescentin [17].…”

Section: Introductionmentioning

confidence: 99%

Two novel heteropolymer‐forming proteins maintain the multicellular shape of the cyanobacterium Anabaena sp. PCC 7120

et al. 2020

View full text Add to dashboard Cite

show abstract

Assembly mechanisms of the bacterial cytoskeletal protein FilP

Cited by 8 publications

References 52 publications

Ultrastructure of Exospore Formation in Streptomyces Revealed by Cryo-Electron Tomography

Ultrastructure of Exospore Formation in Streptomyces Revealed by Cryo-Electron Tomography

Two novel heteropolymer-forming proteins maintain multicellular shape of the cyanobacteriumAnabaenasp. PCC 7120

Two novel heteropolymer‐forming proteins maintain the multicellular shape of the cyanobacterium Anabaena sp. PCC 7120

Contact Info

Product

Resources

About