scholarly journals Altered N-glycan composition impacts flagella-mediated adhesion in Chlamydomonas reinhardtii

eLife ◽  
2020 ◽  
Vol 9 ◽  
Author(s):  
Nannan Xu ◽  
Anne Oltmanns ◽  
Longsheng Zhao ◽  
Antoine Girot ◽  
Marzieh Karimi ◽  
...  
Keyword(s):  
Chlamydomonas Reinhardtii ◽  
Protein Import ◽  
Adhesion Force ◽  
Intraflagellar Transport ◽  
Cell Interaction ◽  
Polystyrene Bead ◽  
Surface Adhesion ◽  
Knockout Mutant ◽  
Force Microscopy ◽  
Flagellar Proteins

For the unicellular alga Chlamydomonas reinhardtii, the presence of N-glycosylated proteins on the surface of two flagella is crucial for both cell-cell interaction during mating and flagellar surface adhesion. However, it is not known whether only the presence or also the composition of N-glycans attached to respective proteins is important for these processes. To this end, we tested several C. reinhardtii insertional mutants and a CRISPR/Cas9 knockout mutant of xylosyltransferase 1A, all possessing altered N-glycan compositions. Taking advantage of atomic force microscopy and micropipette force measurements, our data revealed that reduction in N-glycan complexity impedes the adhesion force required for binding the flagella to surfaces. This results in impaired polystyrene bead binding and transport but not gliding of cells on solid surfaces. Notably, assembly, intraflagellar transport, and protein import into flagella are not affected by altered N-glycosylation. Thus, we conclude that proper N-glycosylation of flagellar proteins is crucial for adhering C. reinhardtii cells onto surfaces, indicating that N-glycans mediate surface adhesion via direct surface contact.

scholarly journals Altered N-glycan composition impacts flagella mediated adhesion in Chlamydomonas reinhardtii

2020 ◽  
Author(s):  
Nannan Xu ◽  
Anne Oltmanns ◽  
Longsheng Zhao ◽  
Antoine Girot ◽  
Marzieh Karimi ◽  
...  
Keyword(s):  
Chlamydomonas Reinhardtii ◽  
Adhesion Force ◽  
Intraflagellar Transport ◽  
Cell Interaction ◽  
Polystyrene Bead ◽  
Surface Adhesion ◽  
Knockout Mutant ◽  
Force Microscopy ◽  
Atomic Force ◽  
Flagellar Proteins

AbstractFor the unicellular alga Chlamydomonas reinhardtii, the presence of N-glycosylated proteins on the surface of two flagella is crucial for both cell-cell interaction during mating and flagellar surface adhesion. It is unknown whether the composition of N-glycans attached to respective proteins is important for these processes. To this end, we examined several C. reinhardtii insertional mutants and a CRIPSR/Cas9 knockout mutant of xylosyltransferase 1A, all possessing altered N-glycan compositions. Taking advantage of atomic force microscopy and micropipette force measurements, our data revealed that reduction in N-glycan complexity impedes the adhesion force required for binding the flagella to surfaces. In addition, polystyrene bead binding and transport is impaired. Notably, assembly, Intraflagellar Transport and FMG-1B transport into flagella are not affected by altered N-glycosylation. Thus, we conclude that proper N-glycosylation of flagellar proteins is crucial for adhering C. reinhardtii cells onto surfaces, indicating that N-glycans mediate surface adhesion via direct surface contact.

scholarly journals Molecular Recognition and Cell Surface Biochemical Response of Bacillus thuringiensis on Triphenyltin

Processes ◽  
2019 ◽  
Vol 7 (6) ◽  
pp. 358
Author(s):  
Hongling Zhang ◽  
Jinshao Ye ◽  
Huaming Qin ◽  
Xujun Liang ◽  
Yan Long
Keyword(s):  
Bacillus Thuringiensis ◽  
Molecular Recognition ◽  
Cell Surface ◽  
Adhesion Force ◽  
Tween 80 ◽  
Cell Permeability ◽  
Surface Adhesion ◽  
Force Microscopy ◽  
Growth Status ◽  
Atomic Force

Triphenyltin (TPT) has severely polluted the environment, and it often coexists with metal ions, such as Cu2+. This paper describes the cell’s molecular recognition of TPT, the interaction between TPT recognition and Cu2+ biosorption, and their effect on cell permeability. We studied the recognition of TPT by Bacillus thuringiensis cells and the effect of TPT recognition on Cu2+ biosorption by using atomic force microscopy to observe changes in cell surface mechanical properties and cellular morphology and by using flow cytometry to determine the cell growth status and cell permeability. The results show that B. thuringiensis can quickly recognize different media. The adhesion force of cells in contact with Tween 80 was significantly reduced to levels that were much lower than that of cells in contact with PBS. Conversely, the cell surface adhesion force increased as TPT became more degraded. B. thuringiensis cells maintained their original morphology after 48 h of TPT treatment. The amount of Cu2+ adsorption by TPT-treated cells was positively correlated with the surface adhesion force (r = 0.966, P = 0.01). The cell adhesion force significantly decreased after Cu2+ adsorption, and cell recognition of TPT and/or Cu2+ hindered the entrance of 2’,7’-dichlorodihydrofluorescein diacetate (DCFH-DA) into the cell. The initial diffusion time of DCFH-DA into cells treated by PBS, Cu2+, TPT, and TPT+Cu2+ was 4, 10, 30, and 30 min, respectively, and the order of the fluorescence intensity was PBS >> Cu2+ > TPT > TPT+Cu2+. We conclude that changes in the cell surface properties of the microbe during recognition of pollutants depend on the contaminant’s properties. B. thuringiensis recognized TPT and secreted intracellular substances that not only enhanced the adsorption of Cu2+, but also formed a “barrier” on the cell surface that reduced permeability. These findings provide a novel insight into the mechanism of microbial removal of pollutants.

scholarly journals Nanoscale mapping of dielectric properties based on surface adhesion force measurements

2018 ◽  
Vol 9 ◽  
pp. 900-906 ◽  
Author(s):  
Ying Wang ◽  
Yue Shen ◽  
Xingya Wang ◽  
Zhiwei Shen ◽  
Bin Li ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Dielectric Properties ◽  
Adhesion Force ◽  
Model Systems ◽  
Adhesion Forces ◽  
Surface Adhesion ◽  
Storage Devices ◽  
Force Microscopy ◽  
Atomic Force

The detection of local dielectric properties is of great importance in a wide variety of scientific studies and applications. Here, we report a novel method for the characterization of local dielectric distributions based on surface adhesion mapping by atomic force microscopy (AFM). The two-dimensional (2D) materials graphene oxide (GO), and partially reduced graphene oxide (RGO), which have similar thicknesses but large differences in their dielectric properties, were studied as model systems. Through direct imaging of the samples with a biased AFM tip in PeakForce Quantitative Nano-Mechanics (PF-QNM) mode, the local dielectric properties of GO and RGO were revealed by mapping their surface adhesion forces. Thus, GO and RGO could be conveniently differentiated. This method provides a simple and general approach for the fast characterization of the local dielectric properties of graphene-based materials and will further facilitate their applications in energy generation and storage devices.

scholarly journals Quantitative Nanomechanical Mapping of Polyolefin Elastomer at Nanoscale with Atomic Force Microscopy

2021 ◽  
Vol 16 (1) ◽  
Author(s):  
Shuting Zhang ◽  
Yihui Weng ◽  
Chunhua Ma
Keyword(s):  
Mechanical Properties ◽  
Elastic Modulus ◽  
Mechanical Response ◽  
Adhesion Force ◽  
Time Dependent ◽  
Surface Adhesion ◽  
Force Microscopy ◽  
Mechanics Model ◽  
Atomic Force ◽  
Force Volume

AbstractElastomeric nanostructures are normally expected to fulfill an explicit mechanical role and therefore their mechanical properties are pivotal to affect material performance. Their versatile applications demand a thorough understanding of the mechanical properties. In particular, the time dependent mechanical response of low-density polyolefin (LDPE) has not been fully elucidated. Here, utilizing state-of-the-art PeakForce quantitative nanomechanical mapping jointly with force volume and fast force volume, the elastic moduli of LDPE samples were assessed in a time-dependent fashion. Specifically, the acquisition frequency was discretely changed four orders of magnitude from 0.1 up to 2 k Hz. Force data were fitted with a linearized DMT contact mechanics model considering surface adhesion force. Increased Young’s modulus was discovered with increasing acquisition frequency. It was measured 11.7 ± 5.2 MPa at 0.1 Hz and increased to 89.6 ± 17.3 MPa at 2 kHz. Moreover, creep compliance experiment showed that instantaneous elastic modulus E1, delayed elastic modulus E2, viscosity η, retardation time τ were 22.3 ± 3.5 MPa, 43.3 ± 4.8 MPa, 38.7 ± 5.6 MPa s and 0.89 ± 0.22 s, respectively. The multiparametric, multifunctional local probing of mechanical measurement along with exceptional high spatial resolution imaging open new opportunities for quantitative nanomechanical mapping of soft polymers, and can potentially be extended to biological systems.

scholarly journals Assessing the Functional Properties of TiZr Nanotubular Structures for Biomedical Applications, through Nano-Scratch Tests and Adhesion Force Maps

Molecules ◽  
2021 ◽  
Vol 26 (4) ◽  
pp. 900
Author(s):  
Maria Vardaki ◽  
Aida Pantazi ◽  
Ioana Demetrescu ◽  
Marius Enachescu
Keyword(s):  
Surface Roughness ◽  
Functional Properties ◽  
Bacterial Adhesion ◽  
Biomedical Applications ◽  
Adhesion Force ◽  
Roughness Parameters ◽  
Force Microscopy ◽  
Atomic Force ◽  
The Mean ◽  
Scratch Tests

In this work we present the results of a functional properties assessment via Atomic Force Microscopy (AFM)-based surface morphology, surface roughness, nano-scratch tests and adhesion force maps of TiZr-based nanotubular structures. The nanostructures have been electrochemically prepared in a glycerin + 15 vol.% H2O + 0.2 M NH4F electrolyte. The AFM topography images confirmed the successful preparation of the nanotubular coatings. The Root Mean Square (RMS) and average (Ra) roughness parameters increased after anodizing, while the mean adhesion force value decreased. The prepared nanocoatings exhibited a smaller mean scratch hardness value compared to the un-coated TiZr. However, the mean hardness (H) values of the coatings highlight their potential in having reliable mechanical resistances, which along with the significant increase of the surface roughness parameters, which could help in improving the osseointegration, and also with the important decrease of the mean adhesion force, which could lead to a reduction in bacterial adhesion, are providing the nanostructures with a great potential to be used as a better alternative for Ti implants in dentistry.

mRNA abundance changes during flagellar regeneration in Chlamydomonas reinhardtii

1984 ◽  
Vol 4 (3) ◽  
pp. 424-434
Author(s):  
J A Schloss ◽  
C D Silflow ◽  
J L Rosenbaum
Keyword(s):  
Chlamydomonas Reinhardtii ◽  
Control Cell ◽  
Beta Tubulin ◽  
Rna Sequences ◽  
Class V ◽  
Alpha Tubulin ◽  
Flagellar Regeneration ◽  
Flagellar Proteins ◽  
Kinetics Of ◽  
Class Iv

Flagellar amputation in Chlamydomonas reinhardtii induces the accumulation of a specific set of RNAs, many of which encode flagellar proteins. We prepared a cDNA clone bank from RNA isolated from cells undergoing flagellar regeneration. From this bank, we selected clones that contain RNA sequences that display several different patterns of abundance regulation. Based on quantitation of the relative amounts of labeled, cloned cDNAs hybridizing to dots of RNA on nitrocellulose filters, the cloned sequences were divided into five regulatory classes: class I RNAs remain at constant abundance during flagellar regeneration; classes II, III, and IV begin to increase in abundance within a few minutes after deflagellation, reach maximal abundance at successively later times during regeneration, and return to control cell levels within 2 to 3 h; and class V RNA abundance decreases during flagellar regeneration. Alpha- and beta-tubulin mRNAs are included in regulatory class IV. The abundance kinetics of alpha-tubulin mRNAs differ slightly from those of beta-tubulin mRNAs. The availability of these clones makes possible studies on the mechanisms controlling the abundance of a wide variety of different RNA species during flagellar regeneration in Chlamydomonas.

scholarly journals Analysis of Flagellar Phosphoproteins from Chlamydomonas reinhardtii

2009 ◽  
Vol 8 (7) ◽  
pp. 922-932 ◽  
Author(s):  
Jens Boesger ◽  
Volker Wagner ◽  
Wolfram Weisheit ◽  
Maria Mittag
Keyword(s):  
Chlamydomonas Reinhardtii ◽  
Protein Phosphorylation ◽  
Proteome Analysis ◽  
Physiological Status ◽  
Phosphorylation Sites ◽  
Cell Organelles ◽  
Flagellar Proteins ◽  
Reversible Protein Phosphorylation ◽  
Cilia And Flagella

ABSTRACT Cilia and flagella are cell organelles that are highly conserved throughout evolution. For many years, the green biflagellate alga Chlamydomonas reinhardtii has served as a model for examination of the structure and function of its flagella, which are similar to certain mammalian cilia. Proteome analysis revealed the presence of several kinases and protein phosphatases in these organelles. Reversible protein phosphorylation can control ciliary beating, motility, signaling, length, and assembly. Despite the importance of this posttranslational modification, the identities of many ciliary phosphoproteins and knowledge about their in vivo phosphorylation sites are still missing. Here we used immobilized metal affinity chromatography to enrich phosphopeptides from purified flagella and analyzed them by mass spectrometry. One hundred forty-one phosphorylated peptides were identified, belonging to 32 flagellar proteins. Thereby, 126 in vivo phosphorylation sites were determined. The flagellar phosphoproteome includes different structural and motor proteins, kinases, proteins with protein interaction domains, and many proteins whose functions are still unknown. In several cases, a dynamic phosphorylation pattern and clustering of phosphorylation sites were found, indicating a complex physiological status and specific control by reversible protein phosphorylation in the flagellum.

Characterization of English ivy (Hedera helix) adhesion force and imaging using atomic force microscopy

2010 ◽  
Vol 13 (3) ◽  
pp. 1029-1037 ◽  
Author(s):  
Lijin Xia ◽  
Scott C. Lenaghan ◽  
Mingjun Zhang ◽  
Yu Wu ◽  
Xiaopeng Zhao ◽  
...  
Keyword(s):  
Atomic Force Microscopy ◽  
Adhesion Force ◽  
Hedera Helix ◽  
Force Microscopy ◽  
Atomic Force ◽  
English Ivy

Surface diagnostics for scale analysis

2004 ◽  
Vol 49 (2) ◽  
pp. 183-190 ◽  
Author(s):  
S. Dunn ◽  
S. Impey ◽  
C. Kimpton ◽  
S.A. Parsons ◽  
J. Doyle ◽  
...  
Keyword(s):  
Adhesion Force ◽  
Polymer Materials ◽  
Rapid Screening ◽  
Force Measurements ◽  
Energy Materials ◽  
Force Microscopy ◽  
Atomic Force ◽  
Surface Modified ◽  
Surface Diagnostics ◽  
Microscopy Techniques

Stainless steel, polymethylmethacrylate and polytetrafluoroethylene coupons were analysed for surface topographical and adhesion force characteristics using tapping mode atomic force microscopy and force-distance microscopy techniques. The two polymer materials were surface modified by polishing with silicon carbide papers of known grade. The struvite scaling rate was determined for each coupon and related to the data gained from the surface analysis. The scaling rate correlated well with adhesion force measurements indicating that lower energy materials scale at a lower rate. The techniques outlined in the paper provide a method for the rapid screening of materials in potential scaling applications.

Sign in / Sign up

Export Citation Format

Share Document