1
|
Bonacquisti EE, Ferguson SW, Wadsworth GM, Jasiewicz NE, Wang J, Chaudhari AP, Kussatz CC, Nogueira AT, Keeley DP, Itano MS, Bolton ML, Hahn KM, Banerjee PR, Nguyen J. Fluorogenic RNA-based biomaterials for imaging and tracking the cargo of extracellular vesicles. J Control Release 2024; 374:349-368. [PMID: 39111600 DOI: 10.1016/j.jconrel.2024.07.043] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2024] [Revised: 07/15/2024] [Accepted: 07/17/2024] [Indexed: 08/25/2024]
Abstract
Extracellular vesicles (EVs), or exosomes, play important roles in physiological and pathological cellular communication and have gained substantial traction as biological drug carriers. EVs contain both short and long non-coding RNAs that regulate gene expression and epigenetic processes. To fully capitalize on the potential of EVs as drug carriers, it is important to study and understand the intricacies of EV function and EV RNA-based communication. Here we developed a genetically encodable RNA-based biomaterial, termed EXO-Probe, for tracking EV RNAs. The EXO-Probe comprises an EV-loading RNA sequence (EXO-Code), fused to a fluorogenic RNA Mango aptamer for RNA imaging. This fusion construct allowed the visualization and tracking of EV RNA and colocalization with markers of multivesicular bodies; imaging RNA within EVs, and non-destructive quantification of EVs. Overall, the new RNA-based biomaterial provides a useful and versatile means to interrogate the role of EVs in cellular communication via RNA trafficking to EVs and to study cellular sorting decisions. The system will also help lay the foundation to further improve the therapeutic efficacy of EVs as drug carriers.
Collapse
Affiliation(s)
- Emily E Bonacquisti
- Division of Pharmacoengineering and Molecular Pharmaceutics, Eshelman School of Pharmacy, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Scott W Ferguson
- Department of Pharmaceutical Sciences, University at Buffalo, USA
| | - Gable M Wadsworth
- Department of Physics, University at Buffalo, State University of New York, Buffalo, NY, 14260, USA
| | - Natalie E Jasiewicz
- Division of Pharmacoengineering and Molecular Pharmaceutics, Eshelman School of Pharmacy, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Jinli Wang
- Department of Biomedical Engineering, University at Buffalo, State University of New York, Buffalo, NY, 14260, USA
| | - Ameya P Chaudhari
- Division of Pharmacoengineering and Molecular Pharmaceutics, Eshelman School of Pharmacy, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Caden C Kussatz
- Division of Pharmacoengineering and Molecular Pharmaceutics, Eshelman School of Pharmacy, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Ana T Nogueira
- Department of Pharmacology, University of North Carolina at Chapel Hill, NC 27599, USA
| | - Daniel P Keeley
- UNC Neuroscience Microscopy Core, Carolina Institute for Developmental Disabilities, UNC Neuroscience Center, University of North Carolina at Chapel Hill, NC 25799, USA
| | - Michelle S Itano
- UNC Neuroscience Microscopy Core, Carolina Institute for Developmental Disabilities, UNC Neuroscience Center, University of North Carolina at Chapel Hill, NC 25799, USA; Department of Cell Biology and Physiology, University of North Carolina at Chapel Hill, NC 27599, USA
| | - Matthew L Bolton
- Department of Systems and Information Engineering, University of Virginia, Charlottesville, 22903, USA
| | - Klaus M Hahn
- Department of Pharmacology, University of North Carolina at Chapel Hill, NC 27599, USA
| | - Priya R Banerjee
- Department of Physics, University at Buffalo, State University of New York, Buffalo, NY, 14260, USA
| | - Juliane Nguyen
- Division of Pharmacoengineering and Molecular Pharmaceutics, Eshelman School of Pharmacy, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA.
| |
Collapse
|
2
|
Schleyer G, Patterson EA, Curran JM. Label free tracking to quantify nanoparticle diffusion through biological media. Sci Rep 2024; 14:18822. [PMID: 39138253 PMCID: PMC11322355 DOI: 10.1038/s41598-024-69506-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2024] [Accepted: 08/06/2024] [Indexed: 08/15/2024] Open
Abstract
Nanotechnology is a rapidly evolving field and has been extensively studied in biological applications. An understanding of the factors that influence nanoparticle diffusion in biofluids can aid in the development of diverse technologies. The development of real-time, label-free tracking technologies would allow the expansion of current knowledge of the diffusion and activity of nanoparticles. Fluorescence-based microscopy is one of the most widespread tools to monitor and track nanoparticle dynamics; however, the influence of fluorescent tags on diffusion and biological activity is still unclear. In this study, we experimentally determined the diffusion coefficient of gold nanoparticles using a label-free, optical tracking technique and evaluated the influence of protein concentration, charge and diameter on nanoparticle diffusion through biological media. We dispersed positively- and negatively-charged nanoparticles with diameters varying from 10 to 100 nm in a common cell culture media with different concentrations of serum proteins. Our results show that dynamic protein interactions influence nanoparticle diffusion in the range of serum concentrations tested. Experimental regimes to obtain quantitative information on the factors that influence the dynamics of nanoparticles in biological media have been developed.
Collapse
Affiliation(s)
- Genevieve Schleyer
- Department of Materials, Design & Manufacturing Engineering, University of Liverpool, Brownlow Hill, Liverpool, UK.
| | - Eann A Patterson
- Department of Mechanical and Aerospace Engineering, University of Liverpool, Brownlow Hill, Liverpool, UK
| | - Judith M Curran
- Department of Materials, Design & Manufacturing Engineering, University of Liverpool, Brownlow Hill, Liverpool, UK
| |
Collapse
|
3
|
Garate X, Gómez-García PA, Merino MF, Angles MC, Zhu C, Castells-García A, Ed-Daoui I, Martin L, Ochiai H, Neguembor MV, Cosma MP. The relationship between nanoscale genome organization and gene expression in mouse embryonic stem cells during pluripotency transition. Nucleic Acids Res 2024; 52:8146-8164. [PMID: 38850157 DOI: 10.1093/nar/gkae476] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2023] [Revised: 05/16/2024] [Accepted: 06/05/2024] [Indexed: 06/10/2024] Open
Abstract
During early development, gene expression is tightly regulated. However, how genome organization controls gene expression during the transition from naïve embryonic stem cells to epiblast stem cells is still poorly understood. Using single-molecule microscopy approaches to reach nanoscale resolution, we show that genome remodeling affects gene transcription during pluripotency transition. Specifically, after exit from the naïve pluripotency state, chromatin becomes less compacted, and the OCT4 transcription factor has lower mobility and is more bound to its cognate sites. In epiblast cells, the active transcription hallmark, H3K9ac, decreases within the Oct4 locus, correlating with reduced accessibility of OCT4 and, in turn, with reduced expression of Oct4 nascent RNAs. Despite the high variability in the distances between active pluripotency genes, distances between Nodal and Oct4 decrease during epiblast specification. In particular, highly expressed Oct4 alleles are closer to nuclear speckles during all stages of the pluripotency transition, while only a distinct group of highly expressed Nodal alleles are in close proximity to Oct4 when associated with a nuclear speckle in epiblast cells. Overall, our results provide new insights into the role of the spatiotemporal genome remodeling during mouse pluripotency transition and its correlation with the expression of key pluripotency genes.
Collapse
Affiliation(s)
- Ximena Garate
- Centre for Genomic Regulation (CRG), The Barcelona Institute of Science and Technology, Dr. Aiguader 88, Barcelona 08003, Spain
| | - Pablo Aurelio Gómez-García
- Centre for Genomic Regulation (CRG), The Barcelona Institute of Science and Technology, Dr. Aiguader 88, Barcelona 08003, Spain
| | - Manuel Fernández Merino
- Centre for Genomic Regulation (CRG), The Barcelona Institute of Science and Technology, Dr. Aiguader 88, Barcelona 08003, Spain
| | - Marta Cadevall Angles
- Centre for Genomic Regulation (CRG), The Barcelona Institute of Science and Technology, Dr. Aiguader 88, Barcelona 08003, Spain
| | - Chenggan Zhu
- Centre for Genomic Regulation (CRG), The Barcelona Institute of Science and Technology, Dr. Aiguader 88, Barcelona 08003, Spain
| | - Alvaro Castells-García
- Medical Research Institute, Guangdong Provincial People's Hospital (Guangdong Academy of Medical Sciences), Southern Medical University, 106 Zhongshan Er Road, Yuexiu district, 510080 Guangzhou, China
| | - Ilyas Ed-Daoui
- Medical Research Institute, Guangdong Provincial People's Hospital (Guangdong Academy of Medical Sciences), Southern Medical University, 106 Zhongshan Er Road, Yuexiu district, 510080 Guangzhou, China
| | - Laura Martin
- Centre for Genomic Regulation (CRG), The Barcelona Institute of Science and Technology, Dr. Aiguader 88, Barcelona 08003, Spain
| | - Hiroshi Ochiai
- Graduate School of Integrated Sciences for Life, Hiroshima University, Higashi-Hiroshima, 739-0046, Japan
| | - Maria Victoria Neguembor
- Centre for Genomic Regulation (CRG), The Barcelona Institute of Science and Technology, Dr. Aiguader 88, Barcelona 08003, Spain
| | - Maria Pia Cosma
- Centre for Genomic Regulation (CRG), The Barcelona Institute of Science and Technology, Dr. Aiguader 88, Barcelona 08003, Spain
- Medical Research Institute, Guangdong Provincial People's Hospital (Guangdong Academy of Medical Sciences), Southern Medical University, 106 Zhongshan Er Road, Yuexiu district, 510080 Guangzhou, China
- ICREA, Pg. Lluis Companys 23, Barcelona 08010, Spain
- Universitat Pompeu Fabra (UPF), Barcelona, Spain
| |
Collapse
|
4
|
Schirripa Spagnolo C, Luin S. Trajectory Analysis in Single-Particle Tracking: From Mean Squared Displacement to Machine Learning Approaches. Int J Mol Sci 2024; 25:8660. [PMID: 39201346 PMCID: PMC11354962 DOI: 10.3390/ijms25168660] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2024] [Revised: 08/01/2024] [Accepted: 08/07/2024] [Indexed: 09/02/2024] Open
Abstract
Single-particle tracking is a powerful technique to investigate the motion of molecules or particles. Here, we review the methods for analyzing the reconstructed trajectories, a fundamental step for deciphering the underlying mechanisms driving the motion. First, we review the traditional analysis based on the mean squared displacement (MSD), highlighting the sometimes-neglected factors potentially affecting the accuracy of the results. We then report methods that exploit the distribution of parameters other than displacements, e.g., angles, velocities, and times and probabilities of reaching a target, discussing how they are more sensitive in characterizing heterogeneities and transient behaviors masked in the MSD analysis. Hidden Markov Models are also used for this purpose, and these allow for the identification of different states, their populations and the switching kinetics. Finally, we discuss a rapidly expanding field-trajectory analysis based on machine learning. Various approaches, from random forest to deep learning, are used to classify trajectory motions, which can be identified by motion models or by model-free sets of trajectory features, either previously defined or automatically identified by the algorithms. We also review free software available for some of the analysis methods. We emphasize that approaches based on a combination of the different methods, including classical statistics and machine learning, may be the way to obtain the most informative and accurate results.
Collapse
Affiliation(s)
| | - Stefano Luin
- NEST Laboratory, Scuola Normale Superiore, Piazza San Silvestro 12, I-56127 Pisa, Italy
- NEST Laboratory, Istituto Nanoscienze-CNR, Piazza San Silvestro 12, I-56127 Pisa, Italy
| |
Collapse
|
5
|
Moores AN, Uphoff S. Robust Quantification of Live-Cell Single-Molecule Tracking Data for Fluorophores with Different Photophysical Properties. J Phys Chem B 2024; 128:7291-7303. [PMID: 38859654 PMCID: PMC11301680 DOI: 10.1021/acs.jpcb.4c01454] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/12/2024]
Abstract
High-speed single-molecule tracking in live cells is becoming an increasingly popular method for quantifying the spatiotemporal behavior of proteins in vivo. The method provides a wealth of quantitative information, but users need to be aware of biases that can skew estimates of molecular mobilities. The range of suitable fluorophores for live-cell single-molecule imaging has grown substantially over the past few years, but it remains unclear to what extent differences in photophysical properties introduce biases. Here, we tested two fluorophores with entirely different photophysical properties, one that photoswitches frequently between bright and dark states (TMR) and one that shows exceptional photostability without photoswitching (JFX650). We used a fusion of the Escherichia coli DNA repair enzyme MutS to the HaloTag and optimized sample preparation and imaging conditions for both types of fluorophore. We then assessed the reliability of two common data analysis algorithms, mean-square displacement (MSD) analysis and Hidden Markov Modeling (HMM), to estimate the diffusion coefficients and fractions of MutS molecules in different states of motion. We introduce a simple approach that removes discrepancies in the data analyses and show that both algorithms yield consistent results, regardless of the fluorophore used. Nevertheless, each dye has its own strengths and weaknesses, with TMR being more suitable for sampling the diffusive behavior of many molecules, while JFX650 enables prolonged observation of only a few molecules per cell. These characterizations and recommendations should help to standardize measurements for increased reproducibility and comparability across studies.
Collapse
Affiliation(s)
- Amy N Moores
- Department of Biochemistry, University of Oxford, South Parks Rd, Oxford OX1 3QU, U.K
| | - Stephan Uphoff
- Department of Biochemistry, University of Oxford, South Parks Rd, Oxford OX1 3QU, U.K
| |
Collapse
|
6
|
Wang LM, Kim J, Han KY. Highly sensitive volumetric single-molecule imaging. NANOPHOTONICS 2024; 13:3805-3814. [PMID: 39224784 PMCID: PMC11366074 DOI: 10.1515/nanoph-2024-0152] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/22/2024] [Accepted: 07/02/2024] [Indexed: 09/04/2024]
Abstract
Volumetric subcellular imaging has long been essential for studying structures and dynamics in cells and tissues. However, due to limited imaging speed and depth of field, it has been challenging to perform live-cell imaging and single-particle tracking. Here we report a 2.5D fluorescence microscopy combined with highly inclined illumination beams, which significantly reduce not only the image acquisition time but also the out-of-focus background by ∼2-fold compared to epi-illumination. Instead of sequential z-scanning, our method projects a certain depth of volumetric information onto a 2D plane in a single shot using multi-layered glass for incoherent wavefront splitting, enabling high photon detection efficiency. We apply our method to multi-color immunofluorescence imaging and volumetric super-resolution imaging, covering ∼3-4 µm thickness of samples without z-scanning. Additionally, we demonstrate that our approach can substantially extend the observation time of single-particle tracking in living cells.
Collapse
Affiliation(s)
- Le-Mei Wang
- CREOL, The College of Optics and Photonics, University of Central Florida, Orlando, FL, USA
| | - Jiah Kim
- Department of Cell and Developmental Biology, University of Illinois at Urbana-Champaign, Urbana, IL, USA
| | - Kyu Young Han
- CREOL, The College of Optics and Photonics, University of Central Florida, Orlando, FL, USA
| |
Collapse
|
7
|
He H, Li L, Ya R, Liu H, Luo B, Li Z, Tian W. Molecular dynamics simulation and experimental verification of the effects of vinyl silicone oil viscosity on the mechanical properties of silicone rubber foam. RSC Adv 2024; 14:23840-23852. [PMID: 39081658 PMCID: PMC11287115 DOI: 10.1039/d4ra04784b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2024] [Accepted: 07/17/2024] [Indexed: 08/02/2024] Open
Abstract
The molecular motion trajectories of silicone rubber foam (SRF) at various vinyl silicone oil viscosities were studied via molecular dynamics (MD) simulation from the perspective of all atomic molecules. The influence of different viscosities of vinyl silicone oil on interaction, compatibility, and aggregation degree of molecules was determined based on the mean square displacement, diffusion coefficient, binding energy, solubility parameter, radial distribution function, and radius of gyration. The mechanical properties of the SRF were also experimentally verified. Results revealed that as the viscosity of vinyl silicone oil increased, the mean square displacement, fractional free volume, diffusion coefficient, and solubility parameter of the system decreased, whereas its larger radius of gyration increased. Moreover, the radial distribution function showed a weaker relative interaction between molecular chains. The calculated binding energy demonstrated that the system had better compatibility at a viscosity of 0.45 Pa s. This study provided a deeper insight into the relation between the viscosity of vinyl silicone oil and mechanical properties of the SRF. As the viscosity of vinyl silicone oil increased, the changing trend in MD simulation results of elastic modulus, shear modulus, bulk modulus, and Poisson's ratio was consistent with the experimental results. The MD simulations can promote theoretical predictions and scientific basis for the design of the SRF with desired performances.
Collapse
Affiliation(s)
- Hongyu He
- School of Materials Science and Engineering, University of Science and Technology Beijing Beijing 100083 China
- School of Materials Science and Engineering, Shunde Innovation School, University of Science and Technology Beijing Foshan 528300 China
| | - Lulu Li
- School of Materials Science and Engineering, University of Science and Technology Beijing Beijing 100083 China
| | - Ruhan Ya
- Inner Mongolia Academy of Science and Technology Huhhot 010020 China
| | - Hong Liu
- Guangdong Homeen Organic Silicon Material Co., Ltd Zhaoqing 526072 China
| | - Bin Luo
- Guangdong Homeen Organic Silicon Material Co., Ltd Zhaoqing 526072 China
| | - Zhipeng Li
- School of Materials Science and Engineering, Shunde Innovation School, University of Science and Technology Beijing Foshan 528300 China
| | - Wenhuai Tian
- School of Materials Science and Engineering, Shunde Innovation School, University of Science and Technology Beijing Foshan 528300 China
| |
Collapse
|
8
|
Inoue S, Nagao J, Kawamoto K, Kan-o K, Fukuyama S, Sasaki S, Kudo S, Okamoto I, Sera T. Overstretching alveolar epithelial type II cells decreases surfactant secretion via actin polymerization and intracellular trafficking alteration. Heliyon 2024; 10:e33499. [PMID: 39040228 PMCID: PMC11260927 DOI: 10.1016/j.heliyon.2024.e33499] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2024] [Revised: 05/27/2024] [Accepted: 06/21/2024] [Indexed: 07/24/2024] Open
Abstract
Pulmonary surfactant is essential for maintaining proper lung function. Alveolar epithelial type II (AE2) cells secrete surfactants via lamellar bodies (LBs). In tidal loading during each breath, the physiological cyclic stretching of AE2 cells promotes surfactant secretion. Excessive stretching inhibits surfactant secretion, which is considered to contribute to the development of lung damage. However, its precise mechanism remains unknown. This study tested whether actin polymerization and intracellular transport are required for pulmonary surfactant secretion and the association of actin polymerization and transport in identical human AE2-derived A549 cells using live-cell imaging, not in the bulk cells population. We found that overstretching approximately doubled actin polymerization into filaments (F-actin) and suppressed LB secretion by half in the fluorescent area ratio, compared with physiological stretching (F-actin: 1.495 vs 0.643 (P < 0.01); LB: 0.739 vs 0.332 (P < 0.01)). An inhibitor of actin polymerization increased LB secretion. Intracellular tracking using fluorescent particles revealed that cyclic stretching shifted the particle motion perpendicularly to the direction of stretching according to the orientation of the F-actin (proportion of perpendicular axis motion prior particle: 0h 40.12 % vs 2h 63.13 % (P < 0.01)), and particle motion was restricted over time in the cells subjected to overstretching, indicating that overstretching regulates intracellular transport dynamics (proportion of stop motion particle: 0h 1.01 % vs 2h 11.04 % (P < 0.01)). These findings suggest that overstretching changes secretion through the cytoskeleton: overstretching AE2 cells inhibits pulmonary surfactant secretion, at least through accelerating actin polymerization and decreasing intracellular trafficking, and the change in actin orientation would modulate intracellular trafficking.
Collapse
Affiliation(s)
- Shigesato Inoue
- Department of Respiratory Medicine, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan
- Department of Mechanical Engineering, Graduate School of Engineering, Kyushu University, Fukuoka, Japan
| | - Junpei Nagao
- Department of Mechanical Engineering, Graduate School of Engineering, Kyushu University, Fukuoka, Japan
| | - Kouhei Kawamoto
- Department of Mechanical Engineering, Graduate School of Engineering, Kyushu University, Fukuoka, Japan
| | - Keiko Kan-o
- Department of Respiratory Medicine, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan
| | - Satoru Fukuyama
- Department of Respiratory Medicine, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan
- Department of Respiratory Medicine, National Hospital Organization Omuta National Hospital, Fukuoka, Japan
| | - Saori Sasaki
- Department of Mechanical Engineering, Faculty of Engineering, Kyushu University, Fukuoka, Japan
| | - Susumu Kudo
- Department of Mechanical Engineering, Faculty of Engineering, Kyushu University, Fukuoka, Japan
| | - Isamu Okamoto
- Department of Respiratory Medicine, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan
| | - Toshihiro Sera
- Department of Mechanical Engineering, Faculty of Engineering, Kyushu University, Fukuoka, Japan
- Department of Medical and Robotic Engineering Design, Faculty of Advanced Engineering, Tokyo University of Science, Tokyo, Japan
| |
Collapse
|
9
|
Nanes BA, Bhatt K, Azarova E, Rajendran D, Munawar S, Isogai T, Dean KM, Danuser G. Shifts in keratin isoform expression activate motility signals during wound healing. Dev Cell 2024:S1534-5807(24)00389-7. [PMID: 39002537 DOI: 10.1016/j.devcel.2024.06.011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2023] [Revised: 04/15/2024] [Accepted: 06/17/2024] [Indexed: 07/15/2024]
Abstract
Keratin intermediate filaments confer structural stability to epithelial tissues, but the reason this simple mechanical function requires a protein family with 54 isoforms is not understood. During skin wound healing, a shift in keratin isoform expression alters the composition of keratin filaments. If and how this change modulates cellular functions that support epidermal remodeling remains unclear. We report an unexpected effect of keratin isoform variation on kinase signal transduction. Increased expression of wound-associated keratin 6A, but not of steady-state keratin 5, potentiated keratinocyte migration and wound closure without compromising mechanical stability by activating myosin motors to increase contractile force generation. These results substantially expand the functional repertoire of intermediate filaments from their canonical role as mechanical scaffolds to include roles as isoform-tuned signaling scaffolds that organize signal transduction cascades in space and time to influence epithelial cell state.
Collapse
Affiliation(s)
- Benjamin A Nanes
- Department of Dermatology, UT Southwestern Medical Center, Dallas, TX 75390, USA; Lyda Hill Department of Bioinformatics and Cecil H and Ida Green Center for Systems Biology, UT Southwestern Medical Center, Dallas, TX 75390, USA.
| | - Kushal Bhatt
- Lyda Hill Department of Bioinformatics and Cecil H and Ida Green Center for Systems Biology, UT Southwestern Medical Center, Dallas, TX 75390, USA
| | - Evgenia Azarova
- Lyda Hill Department of Bioinformatics and Cecil H and Ida Green Center for Systems Biology, UT Southwestern Medical Center, Dallas, TX 75390, USA
| | - Divya Rajendran
- Lyda Hill Department of Bioinformatics and Cecil H and Ida Green Center for Systems Biology, UT Southwestern Medical Center, Dallas, TX 75390, USA
| | - Sabahat Munawar
- Lyda Hill Department of Bioinformatics and Cecil H and Ida Green Center for Systems Biology, UT Southwestern Medical Center, Dallas, TX 75390, USA
| | - Tadamoto Isogai
- Lyda Hill Department of Bioinformatics and Cecil H and Ida Green Center for Systems Biology, UT Southwestern Medical Center, Dallas, TX 75390, USA
| | - Kevin M Dean
- Lyda Hill Department of Bioinformatics and Cecil H and Ida Green Center for Systems Biology, UT Southwestern Medical Center, Dallas, TX 75390, USA
| | - Gaudenz Danuser
- Lyda Hill Department of Bioinformatics and Cecil H and Ida Green Center for Systems Biology, UT Southwestern Medical Center, Dallas, TX 75390, USA.
| |
Collapse
|
10
|
Dibaji H, Kazemi Nasaban Shotorban A, Grattan RM, Lucero S, Schodt DJ, Lidke KA, Petruccelli J, Lidke DS, Liu S, Chakraborty T. Axial de-scanning using remote focusing in the detection arm of light-sheet microscopy. Nat Commun 2024; 15:5019. [PMID: 38866746 PMCID: PMC11169345 DOI: 10.1038/s41467-024-49291-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2023] [Accepted: 05/31/2024] [Indexed: 06/14/2024] Open
Abstract
Rapid, high-resolution volumetric imaging without moving heavy objectives or disturbing delicate samples remains challenging. Pupil-matched remote focusing offers a promising solution for high NA systems, but the fluorescence signal's incoherent and unpolarized nature complicates its application. Thus, remote focusing is mainly used in the illumination arm with polarized laser light to improve optical coupling. Here, we introduce a novel optical design that can de-scan the axial focus movement in the detection arm of a microscope. Our method splits the fluorescence signal into S and P-polarized light, lets them pass through the remote focusing module separately, and combines them with the camera. This allows us to use only one focusing element to perform aberration-free, multi-color, volumetric imaging without (a) compromising the fluorescent signal and (b) needing to perform sample/detection-objective translation. We demonstrate the capabilities of this scheme by acquiring fast dual-color 4D (3D space + time) image stacks with an axial range of 70 μm and camera-limited acquisition speed. Owing to its general nature, we believe this technique will find its application in many other microscopy techniques that currently use an adjustable Z-stage to carry out volumetric imaging, such as confocal, 2-photon, and light sheet variants.
Collapse
Affiliation(s)
- Hassan Dibaji
- Department of Physics and Astronomy, University of New Mexico, Albuquerque, NM, USA
| | | | - Rachel M Grattan
- Comprehensive Cancer Center, University of New Mexico Health Sciences Center, Albuquerque, NM, USA
- Department of Pathology, University of New Mexico Health Science Center, Albuquerque, NM, USA
| | - Shayna Lucero
- Comprehensive Cancer Center, University of New Mexico Health Sciences Center, Albuquerque, NM, USA
- Department of Pathology, University of New Mexico Health Science Center, Albuquerque, NM, USA
| | - David J Schodt
- Department of Physics and Astronomy, University of New Mexico, Albuquerque, NM, USA
| | - Keith A Lidke
- Department of Physics and Astronomy, University of New Mexico, Albuquerque, NM, USA
- Comprehensive Cancer Center, University of New Mexico Health Sciences Center, Albuquerque, NM, USA
| | - Jonathan Petruccelli
- Department of Physics, University at Albany-State University of NewYork, Albany, NY, USA
| | - Diane S Lidke
- Comprehensive Cancer Center, University of New Mexico Health Sciences Center, Albuquerque, NM, USA
- Department of Pathology, University of New Mexico Health Science Center, Albuquerque, NM, USA
| | - Sheng Liu
- Department of Physics and Astronomy, University of New Mexico, Albuquerque, NM, USA
| | - Tonmoy Chakraborty
- Department of Physics and Astronomy, University of New Mexico, Albuquerque, NM, USA.
- Comprehensive Cancer Center, University of New Mexico Health Sciences Center, Albuquerque, NM, USA.
| |
Collapse
|
11
|
Simon AA, Haye L, Alhalabi A, Gresil Q, Muñoz BM, Mornet S, Reisch A, Le Guével X, Cognet L. Expanding the Palette of SWIR Emitting Nanoparticles Based on Au Nanoclusters for Single-Particle Tracking Microscopy. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2024; 11:e2309267. [PMID: 38639398 PMCID: PMC11199965 DOI: 10.1002/advs.202309267] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/05/2023] [Revised: 03/28/2024] [Indexed: 04/20/2024]
Abstract
Single-molecule localization microscopy has proved promising to unravel the dynamics and molecular architecture of thin biological samples down to nanoscales. For applications in complex, thick biological tissues shifting single-particle emission wavelengths to the shortwave infrared (SWIR also called NIR II) region between 900 to 2100 nm, where biological tissues are more transparent is key. To date, mainly single-walled carbon nanotubes (SWCNTs) enable such applications, but they are inherently 1D objects. Here, 0D ultra-small luminescent gold nanoclusters (AuNCs, <3 nm) and ≈25 nm AuNC-loaded-polymeric particles that can be detected at the single-particle level in the SWIR are presented. Thanks to high brightness and excellent photostability, it is shown that the dynamics of the spherical polymeric particles can be followed at the single-particle level in solution at video rates for minutes. We compared single particle tracking of AuNC-loaded-polymeric particles with that of SWCNT diffusing in agarose gels demonstrating the specificity and complementarity of diffusion properties of these SWIR-emitting nano-objects when exploring a complex environment. This extends the library of photostable SWIR emitting nanomaterials to 0D nano-objects of variable size for single-molecule localization microscopy in the second biological window, opening unprecedented possibilities for mapping the structure and dynamics of complex biological systems.
Collapse
Affiliation(s)
- Apolline A. Simon
- Univ. BordeauxLaboratoire Photonique Numérique et Nanosciences (LP2N)UMR 5298TalenceF‐33400France
- Institut d'Optique Graduate School & CNRSLP2N UMR 5298TalenceF‐33400France
- Univ. BordeauxCNRSBordeaux INPICMCBUMR 5026Pessac33600France
| | - Lucie Haye
- Université de StrasbourgCNRSLaboratoire de Bioimagerie et Pathologies UMR 7021StrasbourgF‐67000France
| | - Abdallah Alhalabi
- University of Grenoble AlpesInstitute for Advanced BiosciencesINSERM1209/CNRS‐UMR5309GrenobleF‐38700France
| | - Quentin Gresil
- Univ. BordeauxLaboratoire Photonique Numérique et Nanosciences (LP2N)UMR 5298TalenceF‐33400France
- Institut d'Optique Graduate School & CNRSLP2N UMR 5298TalenceF‐33400France
| | - Blanca Martín Muñoz
- Univ. BordeauxLaboratoire Photonique Numérique et Nanosciences (LP2N)UMR 5298TalenceF‐33400France
- Institut d'Optique Graduate School & CNRSLP2N UMR 5298TalenceF‐33400France
| | - Stéphane Mornet
- Univ. BordeauxCNRSBordeaux INPICMCBUMR 5026Pessac33600France
| | - Andreas Reisch
- Université de StrasbourgCNRSLaboratoire de Bioimagerie et Pathologies UMR 7021StrasbourgF‐67000France
- Inserm UMR_S 1121CNRS EMR 7003Université de StrasbourgBiomaterials and BioengineeringCentre de Recherche en Biomédecine de Strasbourg1 rue Eugène BoeckelStrasbourgF‐67000France
| | - Xavier Le Guével
- University of Grenoble AlpesInstitute for Advanced BiosciencesINSERM1209/CNRS‐UMR5309GrenobleF‐38700France
| | - Laurent Cognet
- Univ. BordeauxLaboratoire Photonique Numérique et Nanosciences (LP2N)UMR 5298TalenceF‐33400France
- Institut d'Optique Graduate School & CNRSLP2N UMR 5298TalenceF‐33400France
| |
Collapse
|
12
|
Zhang Y, Prasad R, Su S, Lee D, Zhou HX. Amino Acid-Dependent Material Properties of Tetrapeptide Condensates. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.05.14.594233. [PMID: 38798623 PMCID: PMC11118382 DOI: 10.1101/2024.05.14.594233] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2024]
Abstract
Condensates formed by intrinsically disordered proteins mediate a myriad of cellular processes and are linked to pathological conditions including neurodegeneration. Rules of how different types of amino acids (e.g., π-π pairs) dictate the physical properties of biomolecular condensates are emerging, but our understanding of the roles of different amino acids is far from complete. Here we studied condensates formed by tetrapeptides of the form XXssXX, where X is an amino acid and ss represents a disulfide bond along the backbone. Eight peptides form four types of condensates at different concentrations and pH values: droplets (X = F, L, M, P, V, A); amorphous dense liquids (X = L, M, P, V, A); amorphous aggregates (X = W), and gels (X = I, V, A). The peptides exhibit enormous differences in phase equilibrium and material properties, including a 368-fold range in the threshold concentration for phase separation and a 3856-fold range in viscosity. All-atom molecular dynamics simulations provide physical explanations of these results. The present work also reveals widespread critical behaviors, including critical slowing down manifested by the formation of amorphous dense liquids and critical scaling obeyed by fusion speed, with broad implications for condensate function.
Collapse
Affiliation(s)
- Yi Zhang
- Department of Chemistry, University of Illinois Chicago, Chicago IL 60607, USA
| | - Ramesh Prasad
- Department of Chemistry, University of Illinois Chicago, Chicago IL 60607, USA
| | - Siyuan Su
- Department of Chemistry, University of Illinois Chicago, Chicago IL 60607, USA
| | - Daesung Lee
- Department of Chemistry, University of Illinois Chicago, Chicago IL 60607, USA
| | - Huan-Xiang Zhou
- Department of Chemistry, University of Illinois Chicago, Chicago IL 60607, USA
- Department of Physics, University of Illinois Chicago, Chicago IL 60607, USA
| |
Collapse
|
13
|
Schirripa Spagnolo C, Luin S. Impact of temporal resolution in single particle tracking analysis. DISCOVER NANO 2024; 19:87. [PMID: 38724858 PMCID: PMC11082114 DOI: 10.1186/s11671-024-04029-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/06/2024] [Accepted: 04/29/2024] [Indexed: 05/12/2024]
Abstract
Temporal resolution is a key parameter in the observation of dynamic processes, as in the case of single molecules motions visualized in real time in two-dimensions by wide field (fluorescence) microscopy, but a systematic investigation of its effects in all the single particle tracking analysis steps is still lacking. Here we present tools to quantify its impact on the estimation of diffusivity and of its distribution using one of the most popular tracking software for biological applications on simulated data and movies. We found important shifts and different widths for diffusivity distributions, depending on the interplay of temporal sampling conditions with various parameters, such as simulated diffusivity, density of spots, signal-to-noise ratio, lengths of trajectories, and kind of boundaries in the simulation. We examined conditions starting from the ones of experiments on the fluorescently labelled receptor p75NTR, a relatively fast-diffusing membrane receptor (diffusivity around 0.5-1 µm2/s), visualized by TIRF microscopy on the basal membrane of living cells. From the analysis of the simulations, we identified the best conditions in cases similar to these ones; considering also the experiments, we could confirm a range of values of temporal resolution suitable for obtaining reliable diffusivity results. The procedure we present can be exploited in different single particle/molecule tracking applications to find an optimal temporal resolution.
Collapse
Affiliation(s)
| | - Stefano Luin
- NEST Laboratory, Scuola Normale Superiore, Piazza San Silvestro 12, 56127, Pisa, Italy.
- NEST Laboratory, Istituto Nanoscienze-CNR, Piazza San Silvestro 12, 56127, Pisa, Italy.
| |
Collapse
|
14
|
Recouvreux P, Pai P, Dunsing V, Torro R, Ludanyi M, Mélénec P, Boughzala M, Bertrand V, Lenne PF. Transfer of polarity information via diffusion of Wnt ligands in C. elegans embryos. Curr Biol 2024; 34:1853-1865.e6. [PMID: 38604167 DOI: 10.1016/j.cub.2024.03.030] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2023] [Revised: 10/26/2023] [Accepted: 03/18/2024] [Indexed: 04/13/2024]
Abstract
Different signaling mechanisms concur to ensure robust tissue patterning and cell fate instruction during animal development. Most of these mechanisms rely on signaling proteins that are produced, transported, and detected. The spatiotemporal dynamics of signaling molecules are largely unknown, yet they determine signal activity's spatial range and time frame. Here, we use the Caenorhabditis elegans embryo to study how Wnt ligands, an evolutionarily conserved family of signaling proteins, dynamically organize to establish cell polarity in a developing tissue. We identify how Wnt ligands, produced in the posterior half of the embryos, spread extracellularly to transmit information to distant target cells in the anterior half. With quantitative live imaging and fluorescence correlation spectroscopy, we show that Wnt ligands diffuse through the embryo over a timescale shorter than the cell cycle, in the intercellular space, and outside the tissue below the eggshell. We extracted diffusion coefficients of Wnt ligands and their receptor Frizzled and characterized their co-localization. Integrating our different measurements and observations in a simple computational framework, we show how fast diffusion in the embryo can polarize individual cells through a time integration of the arrival of the ligands at the target cells. The polarity established at the tissue level by a posterior Wnt source can be transferred to the cellular level. Our results support a diffusion-based long-range Wnt signaling, which is consistent with the dynamics of developing processes.
Collapse
Affiliation(s)
- Pierre Recouvreux
- Aix Marseille University, CNRS, IBDM, Turing Centre for Living Systems, Marseille, France.
| | - Pritha Pai
- Aix Marseille University, CNRS, IBDM, Turing Centre for Living Systems, Marseille, France
| | - Valentin Dunsing
- Aix Marseille University, CNRS, IBDM, Turing Centre for Living Systems, Marseille, France
| | - Rémy Torro
- Aix Marseille University, CNRS, IBDM, Turing Centre for Living Systems, Marseille, France
| | - Monika Ludanyi
- Aix Marseille University, CNRS, IBDM, Turing Centre for Living Systems, Marseille, France
| | - Pauline Mélénec
- Aix Marseille University, CNRS, IBDM, Turing Centre for Living Systems, Marseille, France
| | - Mariem Boughzala
- Aix Marseille University, CNRS, IBDM, Turing Centre for Living Systems, Marseille, France
| | - Vincent Bertrand
- Aix Marseille University, CNRS, IBDM, Turing Centre for Living Systems, Marseille, France
| | - Pierre-François Lenne
- Aix Marseille University, CNRS, IBDM, Turing Centre for Living Systems, Marseille, France
| |
Collapse
|
15
|
Utsunomiya S, Takebayashi K, Yamaguchi A, Sasamura T, Inaki M, Ueda M, Matsuno K. Left-right Myosin-Is, Myosin1C, and Myosin1D exhibit distinct single molecule behaviors on the plasma membrane of Drosophila macrophages. Genes Cells 2024; 29:380-396. [PMID: 38454557 DOI: 10.1111/gtc.13110] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2023] [Revised: 02/07/2024] [Accepted: 02/14/2024] [Indexed: 03/09/2024]
Abstract
Left-right (LR) asymmetry is crucial for animal development, particularly in Drosophila where LR-asymmetric morphogenesis of organs hinges on cellular-level chirality, termed cell chirality. In this species, two class I myosins, Myosin1D (Myo1D), and Myosin1C (Myo1C), respectively determine dextral (wild type) and sinistral (mirror image) cell chirality. Previous studies demonstrated Myo1D's ability to propel F-actin in leftward circles during in vitro gliding assays, suggesting its mechanochemical role in defining dextral chirality. Conversely, Myo1C propels F-actin without exhibiting LR-directional preference in this assay, suggesting at other properties governing sinistral chirality. Given the interaction of Myo1D and Myo1C with the membrane, we hypothesized that differences in their membrane behaviors might be critical in dictating their dextral or sinistral activities. In this study, employing single-molecule imaging analyses, we investigated the dynamic behaviors of Myo1D and Myo1C on the plasma membrane. Our findings revealed that Myo1C exhibits a significantly greater proportion of slow-diffusing population compared to Myo1D. Importantly, this characteristic was contingent upon both head and tail domains of Myo1C. The distinct diffusion patterns of Myo1D and Myo1C did not exert mutual influence on each other. This divergence in membrane diffusion between Myo1D and Myo1C may be crucial for dictating cell and organ chirality.
Collapse
Affiliation(s)
- Sosuke Utsunomiya
- Department of Biological Sciences, Graduate School of Science, Osaka University, Toyonaka, Japan
| | - Kazutoshi Takebayashi
- Center for Biosystems Dynamics Research (BDR), RIKEN, Suita, Japan
- Graduate School of Frontier Biosciences, Osaka University, Suita, Japan
| | - Asuka Yamaguchi
- Department of Biological Sciences, Graduate School of Science, Osaka University, Toyonaka, Japan
| | - Takeshi Sasamura
- Department of Biological Sciences, Graduate School of Science, Osaka University, Toyonaka, Japan
| | - Mikiko Inaki
- Department of Biological Sciences, Graduate School of Science, Osaka University, Toyonaka, Japan
| | - Masahiro Ueda
- Center for Biosystems Dynamics Research (BDR), RIKEN, Suita, Japan
- Graduate School of Frontier Biosciences, Osaka University, Suita, Japan
| | - Kenji Matsuno
- Department of Biological Sciences, Graduate School of Science, Osaka University, Toyonaka, Japan
| |
Collapse
|
16
|
Nanes BA, Bhatt K, Boujemaa-Paterski R, Azarova E, Munawar S, Rajendran D, Isogai T, Dean KM, Medalia O, Danuser G. Keratin isoform shifts modulate motility signals during wound healing. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2023.05.04.538989. [PMID: 37205459 PMCID: PMC10187270 DOI: 10.1101/2023.05.04.538989] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
Keratin intermediate filaments form strong mechanical scaffolds that confer structural stability to epithelial tissues, but the reason this function requires a protein family with 54 isoforms is not understood. During skin wound healing, a shift in keratin isoform expression alters the composition of keratin filaments. How this change modulates cellular function to support epidermal remodeling remains unclear. We report an unexpected effect of keratin isoform variation on kinase signal transduction. Increased expression of wound-associated keratin 6A, but not of steady-state keratin 5, potentiated keratinocyte migration and wound closure without compromising epidermal stability by activating myosin motors. This pathway depended on isoform-specific interaction between intrinsically disordered keratin head domains and non-filamentous vimentin shuttling myosin-activating kinases. These results substantially expand the functional repertoire of intermediate filaments from their canonical role as mechanical scaffolds to include roles as isoform-tuned signaling scaffolds that organize signal transduction cascades in space and time to influence epithelial cell state.
Collapse
Affiliation(s)
- Benjamin A Nanes
- Department of Dermatology, UT Southwestern Medical Center; Dallas, TX 75390, USA
- Lyda Hill Department of Bioinformatics and Cecil H and Ida Green Center for Systems Biology, UT Southwestern Medical Center; Dallas, TX 75390, USA
| | - Kushal Bhatt
- Lyda Hill Department of Bioinformatics and Cecil H and Ida Green Center for Systems Biology, UT Southwestern Medical Center; Dallas, TX 75390, USA
| | | | - Evgenia Azarova
- Lyda Hill Department of Bioinformatics and Cecil H and Ida Green Center for Systems Biology, UT Southwestern Medical Center; Dallas, TX 75390, USA
- Present address: Department of Materials Science and Engineering, Johns Hopkins University; Baltimore, MD 21218, USA
| | - Sabahat Munawar
- Lyda Hill Department of Bioinformatics and Cecil H and Ida Green Center for Systems Biology, UT Southwestern Medical Center; Dallas, TX 75390, USA
| | - Divya Rajendran
- Lyda Hill Department of Bioinformatics and Cecil H and Ida Green Center for Systems Biology, UT Southwestern Medical Center; Dallas, TX 75390, USA
| | - Tadamoto Isogai
- Lyda Hill Department of Bioinformatics and Cecil H and Ida Green Center for Systems Biology, UT Southwestern Medical Center; Dallas, TX 75390, USA
| | - Kevin M Dean
- Lyda Hill Department of Bioinformatics and Cecil H and Ida Green Center for Systems Biology, UT Southwestern Medical Center; Dallas, TX 75390, USA
| | - Ohad Medalia
- Department of Biochemistry, University of Zurich; Zurich CH-8057, Switzerland
| | - Gaudenz Danuser
- Lyda Hill Department of Bioinformatics and Cecil H and Ida Green Center for Systems Biology, UT Southwestern Medical Center; Dallas, TX 75390, USA
| |
Collapse
|
17
|
Dibaji H, Nasaban Shotorban AK, Grattan RM, Lucero S, Schodt DJ, Lidke KA, Petruccelli J, Lidke DS, Liu S, Chakraborty T. Axial de-scanning using remote focusing in the detection arm of light-sheet microscopy. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2023.09.07.556729. [PMID: 38659774 PMCID: PMC11042218 DOI: 10.1101/2023.09.07.556729] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/26/2024]
Abstract
The ability to image at high speeds is necessary for biological imaging to capture fast-moving or transient events or to efficiently image large samples. However, due to the lack of rigidity of biological specimens, carrying out fast, high-resolution volumetric imaging without moving and agitating the sample has been a challenging problem. Pupil-matched remote focusing has been promising for high NA imaging systems with their low aberrations and wavelength independence, making it suitable for multicolor imaging. However, owing to the incoherent and unpolarized nature of the fluorescence signal, manipulating this emission light through remote focusing is challenging. Therefore, remote focusing has been primarily limited to the illumination arm, using polarized laser light to facilitate coupling in and out of the remote focusing optics. Here, we introduce a novel optical design that can de-scan the axial focus movement in the detection arm of a microscope. Our method splits the fluorescence signal into S and P-polarized light, lets them pass through the remote focusing module separately, and combines them with the camera. This allows us to use only one focusing element to perform aberration-free, multi-color, volumetric imaging without (a) compromising the fluorescent signal and (b) needing to perform sample/detection-objective translation. We demonstrate the capabilities of this scheme by acquiring fast dual-color 4D (3D space + time) image stacks with an axial range of 70 μm and camera-limited acquisition speed. Owing to its general nature, we believe this technique will find its application in many other microscopy techniques that currently use an adjustable Z-stage to carry out volumetric imaging, such as confocal, 2-photon, and light sheet variants.
Collapse
|
18
|
Liu Z, van Veen E, Sánchez H, Solano B, Palmero Moya FJ, McCluskey KA, Ramírez Montero D, van Laar T, Dekker NH. A Biophysics Toolbox for Reliable Data Acquisition and Processing in Integrated Force-Confocal Fluorescence Microscopy. ACS PHOTONICS 2024; 11:1592-1603. [PMID: 38645993 PMCID: PMC11027178 DOI: 10.1021/acsphotonics.3c01739] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/29/2023] [Revised: 03/01/2024] [Accepted: 03/01/2024] [Indexed: 04/23/2024]
Abstract
Integrated single-molecule force-fluorescence spectroscopy setups allow for simultaneous fluorescence imaging and mechanical force manipulation and measurements on individual molecules, providing comprehensive dynamic and spatiotemporal information. Dual-beam optical tweezers (OT) combined with a confocal scanning microscope form a force-fluorescence spectroscopy apparatus broadly used to investigate various biological processes, in particular, protein:DNA interactions. Such experiments typically involve imaging of fluorescently labeled proteins bound to DNA and force spectroscopy measurements of trapped individual DNA molecules. Here, we present a versatile state-of-the-art toolbox including the preparation of protein:DNA complex samples, design of a microfluidic flow cell incorporated with OT, automation of OT-confocal scanning measurements, and the development and implementation of a streamlined data analysis package for force and fluorescence spectroscopy data processing. Its components can be adapted to any commercialized or home-built dual-beam OT setup equipped with a confocal scanning microscope, which will facilitate single-molecule force-fluorescence spectroscopy studies on a large variety of biological systems.
Collapse
Affiliation(s)
- Zhaowei Liu
- Department
of Bionanoscience, Kavli Institute of Nanoscience, Delft University of Technology, 2629 HZ Delft, The Netherlands
| | - Edo van Veen
- Department
of Bionanoscience, Kavli Institute of Nanoscience, Delft University of Technology, 2629 HZ Delft, The Netherlands
| | - Humberto Sánchez
- Department
of Bionanoscience, Kavli Institute of Nanoscience, Delft University of Technology, 2629 HZ Delft, The Netherlands
| | - Belén Solano
- Department
of Bionanoscience, Kavli Institute of Nanoscience, Delft University of Technology, 2629 HZ Delft, The Netherlands
| | - Francisco J. Palmero Moya
- Department
of Bionanoscience, Kavli Institute of Nanoscience, Delft University of Technology, 2629 HZ Delft, The Netherlands
| | - Kaley A. McCluskey
- Department
of Bionanoscience, Kavli Institute of Nanoscience, Delft University of Technology, 2629 HZ Delft, The Netherlands
| | - Daniel Ramírez Montero
- Department
of Bionanoscience, Kavli Institute of Nanoscience, Delft University of Technology, 2629 HZ Delft, The Netherlands
| | - Theo van Laar
- Department
of Bionanoscience, Kavli Institute of Nanoscience, Delft University of Technology, 2629 HZ Delft, The Netherlands
| | - Nynke H. Dekker
- Department
of Bionanoscience, Kavli Institute of Nanoscience, Delft University of Technology, 2629 HZ Delft, The Netherlands
- Clarendon
Laboratory, Department of Physics, University
of Oxford, Oxford OX1 3PU, U.K.
- Kavli
Institute of Nanoscience Discovery, University
of Oxford, Dorothy Crowfoot
Hodgkin Building, Oxford OX1 3QU, U.K.
| |
Collapse
|
19
|
Valverde-Mendez D, Sunol AM, Bratton BP, Delarue M, Hofmann JL, Sheehan JP, Gitai Z, Holt LJ, Shaevitz JW, Zia RN. Macromolecular interactions and geometrical confinement determine the 3D diffusion of ribosome-sized particles in live Escherichia coli cells. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.03.27.587083. [PMID: 38585850 PMCID: PMC10996671 DOI: 10.1101/2024.03.27.587083] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/09/2024]
Abstract
The crowded bacterial cytoplasm is comprised of biomolecules that span several orders of magnitude in size and electrical charge. This complexity has been proposed as the source of the rich spatial organization and apparent anomalous diffusion of intracellular components, although this has not been tested directly. Here, we use biplane microscopy to track the 3D motion of self-assembled bacterial Genetically Encoded Multimeric nanoparticles (bGEMs) with tunable size (20 to 50 nm) and charge (-2160 to +1800 e) in live Escherichia coli cells. To probe intermolecular details at spatial and temporal resolutions beyond experimental limits, we also developed a colloidal whole-cell model that explicitly represents the size and charge of cytoplasmic macromolecules and the porous structure of the bacterial nucleoid. Combining these techniques, we show that bGEMs spatially segregate by size, with small 20-nm particles enriched inside the nucleoid, and larger and/or positively charged particles excluded from this region. Localization is driven by entropic and electrostatic forces arising from cytoplasmic polydispersity, nucleoid structure, geometrical confinement, and interactions with other biomolecules including ribosomes and DNA. We observe that at the timescales of traditional single molecule tracking experiments, motion appears sub-diffusive for all particle sizes and charges. However, using computer simulations with higher temporal resolution, we find that the apparent anomalous exponents are governed by the region of the cell in which bGEMs are located. Molecular motion does not display anomalous diffusion on short time scales and the apparent sub-diffusion arises from geometrical confinement within the nucleoid and by the cell boundary.
Collapse
Affiliation(s)
- Diana Valverde-Mendez
- Department of Physics, Princeton University, Princeton, NJ 08540, USA
- Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, NJ 08540, USA
| | - Alp M. Sunol
- Department of Chemical Engineering, Stanford University, , Stanford, CA 94305, USA
| | - Benjamin P. Bratton
- Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, NJ 08540, USA
- Department of Molecular Biology, Princeton University, Princeton, NJ 08540, USA
- Department of Pathology, Vanderbilt University Medical Center, Vanderbilt University, Nashville, TN 37235, USA
- Department of Cell and Developmental Biology, Vanderbilt University, Nashville, TN 37235, USA
- Vanderbilt Institute for Infection, Inflammation and Immunology, Vanderbilt University, Nashville, TN 37235, USA
| | - Morgan Delarue
- LAAS-CNRS, Université de Toulouse, CNRS, Toulouse, France
| | - Jennifer L. Hofmann
- Department of Chemical Engineering, Stanford University, , Stanford, CA 94305, USA
| | - Joseph P. Sheehan
- Department of Molecular Biology, Princeton University, Princeton, NJ 08540, USA
| | - Zemer Gitai
- Department of Molecular Biology, Princeton University, Princeton, NJ 08540, USA
| | - Liam J. Holt
- Institute for Systems Genetics, New York University School of Medicine, 435 E 30th St, NY 10016, USA
| | - Joshua W. Shaevitz
- Department of Physics, Princeton University, Princeton, NJ 08540, USA
- Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, NJ 08540, USA
| | - Roseanna N. Zia
- Department of Chemical Engineering, Stanford University, , Stanford, CA 94305, USA
| |
Collapse
|
20
|
Pomp W, Meeussen JVW, Lenstra TL. Transcription factor exchange enables prolonged transcriptional bursts. Mol Cell 2024; 84:1036-1048.e9. [PMID: 38377994 PMCID: PMC10962226 DOI: 10.1016/j.molcel.2024.01.020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2023] [Revised: 11/27/2023] [Accepted: 01/24/2024] [Indexed: 02/22/2024]
Abstract
Single-molecule imaging inside living cells has revealed that transcription factors (TFs) bind to DNA transiently, but a long-standing question is how this transient binding is related to transcription activation. Here, we devised a microscopy method to simultaneously measure transient TF binding at a single locus and the effect of these binding events on transcription. We show that DNA binding of the yeast TF Gal4 activates transcription of a target gene within a few seconds, with at least ∼20% efficiency and with a high initiation rate of ∼1 RNA/s. Gal4 DNA dissociation decreases transcription rapidly. Moreover, at a gene with multiple binding sites, individual Gal4 molecules only rarely stay bound throughout the entire burst but instead frequently exchange during a burst to increase the transcriptional burst duration. Our results suggest a mechanism for enhancer regulation in more complex eukaryotes, where TF cooperativity and exchange enable robust and responsive transcription regulation.
Collapse
Affiliation(s)
- Wim Pomp
- Division of Gene Regulation, the Netherlands Cancer Institute, Oncode Institute, Plesmanlaan 121, 1066CX Amsterdam, the Netherlands
| | - Joseph V W Meeussen
- Division of Gene Regulation, the Netherlands Cancer Institute, Oncode Institute, Plesmanlaan 121, 1066CX Amsterdam, the Netherlands
| | - Tineke L Lenstra
- Division of Gene Regulation, the Netherlands Cancer Institute, Oncode Institute, Plesmanlaan 121, 1066CX Amsterdam, the Netherlands.
| |
Collapse
|
21
|
Dukhno O, Ghosh S, Greiner V, Bou S, Godet J, Muhr V, Buchner M, Hirsch T, Mély Y, Przybilla F. Targeted Single Particle Tracking with Upconverting Nanoparticles. ACS APPLIED MATERIALS & INTERFACES 2024; 16:11217-11227. [PMID: 38386424 DOI: 10.1021/acsami.3c17116] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/24/2024]
Abstract
Single particle tracking (SPT) is a powerful technique for real-time microscopic visualization of the movement of individual biomolecules within or on the surface of living cells. However, SPT often suffers from the suboptimal performance of the photon-emitting labels used to tag the biomolecules of interest. For example, fluorescent dyes have poor photostability, while quantum dots suffer from blinking that hampers track acquisition and interpretation. Upconverting nanoparticles (UCNPs) have recently emerged as a promising anti-Stokes luminescent label for SPT. In this work, we demonstrated targeted SPT using UCNPs. For this, we synthesized 30 nm diameter doped UCNPs and coated them with amphiphilic polymers decorated with polyethylene glycol chains to make them water-dispersible and minimize their nonspecific interactions with cells. Coated UCNPs highly homogeneous in brightness (as confirmed by a single particle investigation) were functionalized by immunoglobulin E (IgE) using a biotin-streptavidin strategy. Using these IgE-UCNP SPT labels, we tracked high-affinity IgE receptors (FcεRI) on the membrane of living RBL-2H3 mast cells at 37 °C in the presence and absence of antigen and obtained good agreement with the literature. Moreover, we used the FcεRI-IgE receptor-antibody system to directly compare the performance of UCNP-based SPT labels to organic dyes (AlexaFluor647) and quantum dots (QD655). Due to their photostability as well as their backgroundless and continuous luminescence, SPT trajectories obtained with UCNP labels are no longer limited by the photophysics of the label but only by the dynamics of the system and, in particular, the movement of the label out of the field of view and/or focal plane.
Collapse
Affiliation(s)
- Oleksii Dukhno
- Laboratory of Biomaging and Pathologies, UMR 7021 CNRS, University of Strasbourg, Strasbourg 67000, France
| | - Srijayee Ghosh
- Laboratory of Biomaging and Pathologies, UMR 7021 CNRS, University of Strasbourg, Strasbourg 67000, France
| | - Vanille Greiner
- Laboratory of Biomaging and Pathologies, UMR 7021 CNRS, University of Strasbourg, Strasbourg 67000, France
| | - Sophie Bou
- Laboratory of Biomaging and Pathologies, UMR 7021 CNRS, University of Strasbourg, Strasbourg 67000, France
| | - Julien Godet
- Laboratory of Biomaging and Pathologies, UMR 7021 CNRS, University of Strasbourg, Strasbourg 67000, France
- IMAGeS team at ICube, UMR 7357, CNRS, Université de Strasbourg, Strasbourg 67000, France
| | - Verena Muhr
- Institute of Analytical Chemistry, Chemo- and Biosensors, University of Regensburg, 93040 Regensburg, Germany
| | - Markus Buchner
- Institute of Analytical Chemistry, Chemo- and Biosensors, University of Regensburg, 93040 Regensburg, Germany
| | - Thomas Hirsch
- Institute of Analytical Chemistry, Chemo- and Biosensors, University of Regensburg, 93040 Regensburg, Germany
| | - Yves Mély
- Laboratory of Biomaging and Pathologies, UMR 7021 CNRS, University of Strasbourg, Strasbourg 67000, France
| | - Frédéric Przybilla
- Laboratory of Biomaging and Pathologies, UMR 7021 CNRS, University of Strasbourg, Strasbourg 67000, France
| |
Collapse
|
22
|
Loya-Lopez SI, Allen HN, Duran P, Calderon-Rivera A, Gomez K, Kumar U, Shields R, Zeng R, Dwivedi A, Saurabh S, Korczeniewska OA, Khanna R. Intranasal CRMP2-Ubc9 inhibitor regulates Na V 1.7 to alleviate trigeminal neuropathic pain. Pain 2024; 165:573-588. [PMID: 37751532 PMCID: PMC10922202 DOI: 10.1097/j.pain.0000000000003053] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2023] [Accepted: 07/25/2023] [Indexed: 09/28/2023]
Abstract
ABSTRACT Dysregulation of voltage-gated sodium Na V 1.7 channels in sensory neurons contributes to chronic pain conditions, including trigeminal neuropathic pain. We previously reported that chronic pain results in part from increased SUMOylation of collapsin response mediator protein 2 (CRMP2), leading to an increased CRMP2/Na V 1.7 interaction and increased functional activity of Na V 1.7. Targeting this feed-forward regulation, we developed compound 194 , which inhibits CRMP2 SUMOylation mediated by the SUMO-conjugating enzyme Ubc9. We further demonstrated that 194 effectively reduces the functional activity of Na V 1.7 channels in dorsal root ganglia neurons and alleviated inflammatory and neuropathic pain. Here, we used a comprehensive array of approaches, encompassing biochemical, pharmacological, genetic, electrophysiological, and behavioral analyses, to assess the functional implications of Na V 1.7 regulation by CRMP2 in trigeminal ganglia (TG) neurons. We confirmed the expression of Scn9a , Dpysl2 , and UBE2I within TG neurons. Furthermore, we found an interaction between CRMP2 and Na V 1.7, with CRMP2 being SUMOylated in these sensory ganglia. Disrupting CRMP2 SUMOylation with compound 194 uncoupled the CRMP2/Na V 1.7 interaction, impeded Na V 1.7 diffusion on the plasma membrane, and subsequently diminished Na V 1.7 activity. Compound 194 also led to a reduction in TG neuron excitability. Finally, when intranasally administered to rats with chronic constriction injury of the infraorbital nerve, 194 significantly decreased nociceptive behaviors. Collectively, our findings underscore the critical role of CRMP2 in regulating Na V 1.7 within TG neurons, emphasizing the importance of this indirect modulation in trigeminal neuropathic pain.
Collapse
Affiliation(s)
- Santiago I. Loya-Lopez
- Department of Molecular Pathobiology, College of Dentistry, New York University, New York, New York, United States of America
- NYU Pain Research Center, 433 First Avenue, New York, NY 10010, United States of America
| | - Heather N. Allen
- Department of Molecular Pathobiology, College of Dentistry, New York University, New York, New York, United States of America
- NYU Pain Research Center, 433 First Avenue, New York, NY 10010, United States of America
| | - Paz Duran
- Department of Molecular Pathobiology, College of Dentistry, New York University, New York, New York, United States of America
- NYU Pain Research Center, 433 First Avenue, New York, NY 10010, United States of America
| | - Aida Calderon-Rivera
- Department of Molecular Pathobiology, College of Dentistry, New York University, New York, New York, United States of America
- NYU Pain Research Center, 433 First Avenue, New York, NY 10010, United States of America
| | - Kimberly Gomez
- Department of Molecular Pathobiology, College of Dentistry, New York University, New York, New York, United States of America
- NYU Pain Research Center, 433 First Avenue, New York, NY 10010, United States of America
| | - Upasana Kumar
- Center for Orofacial Pain and Temporomandibular Disorders, Department of Diagnostic Sciences, Rutgers School of Dental Medicine, Newark, NJ 07101, United States of America
| | - Rory Shields
- Rutgers School of Graduate Studies, Newark Health Science Campus, Newark, NJ 07101, United States of America
| | - Rui Zeng
- Department of Chemistry, College of Arts and Sciences, New York University, 100 Washington Square East, New York, NY 10003, United States of America
| | - Akshat Dwivedi
- Department of Chemistry, College of Arts and Sciences, New York University, 100 Washington Square East, New York, NY 10003, United States of America
| | - Saumya Saurabh
- Department of Chemistry, College of Arts and Sciences, New York University, 100 Washington Square East, New York, NY 10003, United States of America
| | - Olga A. Korczeniewska
- Center for Orofacial Pain and Temporomandibular Disorders, Department of Diagnostic Sciences, Rutgers School of Dental Medicine, Newark, NJ 07101, United States of America
- Rutgers School of Graduate Studies, Newark Health Science Campus, Newark, NJ 07101, United States of America
| | - Rajesh Khanna
- Department of Molecular Pathobiology, College of Dentistry, New York University, New York, New York, United States of America
- NYU Pain Research Center, 433 First Avenue, New York, NY 10010, United States of America
- Department of Neuroscience and Physiology and Neuroscience Institute, School of Medicine, New York University, New York, NY, 10010, USA
| |
Collapse
|
23
|
Shrestha R, Carpenter TS, Van QN, Agamasu C, Tonelli M, Aydin F, Chen D, Gulten G, Glosli JN, López CA, Oppelstrup T, Neale C, Gnanakaran S, Gillette WK, Ingólfsson HI, Lightstone FC, Stephen AG, Streitz FH, Nissley DV, Turbyville TJ. Membrane lipids drive formation of KRAS4b-RAF1 RBDCRD nanoclusters on the membrane. Commun Biol 2024; 7:242. [PMID: 38418613 PMCID: PMC10902389 DOI: 10.1038/s42003-024-05916-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2023] [Accepted: 02/14/2024] [Indexed: 03/02/2024] Open
Abstract
The oncogene RAS, extensively studied for decades, presents persistent gaps in understanding, hindering the development of effective therapeutic strategies due to a lack of precise details on how RAS initiates MAPK signaling with RAF effector proteins at the plasma membrane. Recent advances in X-ray crystallography, cryo-EM, and super-resolution fluorescence microscopy offer structural and spatial insights, yet the molecular mechanisms involving protein-protein and protein-lipid interactions in RAS-mediated signaling require further characterization. This study utilizes single-molecule experimental techniques, nuclear magnetic resonance spectroscopy, and the computational Machine-Learned Modeling Infrastructure (MuMMI) to examine KRAS4b and RAF1 on a biologically relevant lipid bilayer. MuMMI captures long-timescale events while preserving detailed atomic descriptions, providing testable models for experimental validation. Both in vitro and computational studies reveal that RBDCRD binding alters KRAS lateral diffusion on the lipid bilayer, increasing cluster size and decreasing diffusion. RAS and membrane binding cause hydrophobic residues in the CRD region to penetrate the bilayer, stabilizing complexes through β-strand elongation. These cooperative interactions among lipids, KRAS4b, and RAF1 are proposed as essential for forming nanoclusters, potentially a critical step in MAP kinase signal activation.
Collapse
Affiliation(s)
- Rebika Shrestha
- RAS Initiative, The Cancer Research Technology Program, Frederick National Laboratory, Frederick, MD, 21701, USA
| | - Timothy S Carpenter
- Physical and Life Sciences (PLS) Directorate, Lawrence Livermore National Laboratory, Livermore, CA, 94550, USA
| | - Que N Van
- RAS Initiative, The Cancer Research Technology Program, Frederick National Laboratory, Frederick, MD, 21701, USA
| | - Constance Agamasu
- RAS Initiative, The Cancer Research Technology Program, Frederick National Laboratory, Frederick, MD, 21701, USA
| | - Marco Tonelli
- National Magnetic Resonance Facility at Madison, Biochemistry Department, University of Wisconsin-Madison, Madison, WI, 53706, USA
| | - Fikret Aydin
- Physical and Life Sciences (PLS) Directorate, Lawrence Livermore National Laboratory, Livermore, CA, 94550, USA
| | - De Chen
- RAS Initiative, The Cancer Research Technology Program, Frederick National Laboratory, Frederick, MD, 21701, USA
| | - Gulcin Gulten
- RAS Initiative, The Cancer Research Technology Program, Frederick National Laboratory, Frederick, MD, 21701, USA
| | - James N Glosli
- Physical and Life Sciences (PLS) Directorate, Lawrence Livermore National Laboratory, Livermore, CA, 94550, USA
| | - Cesar A López
- Theoretical Biology and Biophysics Group, Los Alamos National Laboratory, Los Alamos, NM, 87545, USA
| | - Tomas Oppelstrup
- Physical and Life Sciences (PLS) Directorate, Lawrence Livermore National Laboratory, Livermore, CA, 94550, USA
| | - Chris Neale
- Theoretical Biology and Biophysics Group, Los Alamos National Laboratory, Los Alamos, NM, 87545, USA
| | - Sandrasegaram Gnanakaran
- Theoretical Biology and Biophysics Group, Los Alamos National Laboratory, Los Alamos, NM, 87545, USA
| | - William K Gillette
- RAS Initiative, The Cancer Research Technology Program, Frederick National Laboratory, Frederick, MD, 21701, USA
| | - Helgi I Ingólfsson
- Physical and Life Sciences (PLS) Directorate, Lawrence Livermore National Laboratory, Livermore, CA, 94550, USA
| | - Felice C Lightstone
- Physical and Life Sciences (PLS) Directorate, Lawrence Livermore National Laboratory, Livermore, CA, 94550, USA
| | - Andrew G Stephen
- RAS Initiative, The Cancer Research Technology Program, Frederick National Laboratory, Frederick, MD, 21701, USA
| | - Frederick H Streitz
- Physical and Life Sciences (PLS) Directorate, Lawrence Livermore National Laboratory, Livermore, CA, 94550, USA
| | - Dwight V Nissley
- RAS Initiative, The Cancer Research Technology Program, Frederick National Laboratory, Frederick, MD, 21701, USA
| | - Thomas J Turbyville
- RAS Initiative, The Cancer Research Technology Program, Frederick National Laboratory, Frederick, MD, 21701, USA.
| |
Collapse
|
24
|
Štefl M, Takamiya M, Middel V, Tekpınar M, Nienhaus K, Beil T, Rastegar S, Strähle U, Nienhaus GU. Caveolae disassemble upon membrane lesioning and foster cell survival. iScience 2024; 27:108849. [PMID: 38303730 PMCID: PMC10831942 DOI: 10.1016/j.isci.2024.108849] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2023] [Revised: 11/22/2023] [Accepted: 01/03/2024] [Indexed: 02/03/2024] Open
Abstract
Repair of lesions in the plasma membrane is key to sustaining cellular homeostasis. Cells maintain cytoplasmic as well as membrane-bound stores of repair proteins that can rapidly precipitate at the site of membrane lesions. However, little is known about the origins of lipids and proteins for resealing and repair of the plasma membrane. Here we study the dynamics of caveolar proteins after laser-induced lesioning of plasma membranes of mammalian C2C12 tissue culture cells and muscle cells of intact zebrafish embryos. Single-molecule diffusivity measurements indicate that caveolar clusters break up into smaller entities after wounding. Unlike Annexins and Dysferlin, caveolar proteins do not accumulate at the lesion patch. In caveolae-depleted cavin1a knockout zebrafish embryos, lesion patch formation is impaired, and injured cells show reduced survival. Our data suggest that caveolae disassembly releases surplus plasma membrane near the lesion to facilitate membrane repair after initial patch formation for emergency sealing.
Collapse
Affiliation(s)
- Martin Štefl
- Institute of Applied Physics (APH), Karlsruhe Institute of Technology (KIT), Wolfgang Gaede-Strasse 1, 76131 Karlsruhe, Germany
| | - Masanari Takamiya
- Institute of Biological and Chemical Systems (IBCS), Karlsruhe Institute of Technology (KIT), PO Box 3640, 76021 Karlsruhe, Germany
| | - Volker Middel
- Institute of Biological and Chemical Systems (IBCS), Karlsruhe Institute of Technology (KIT), PO Box 3640, 76021 Karlsruhe, Germany
| | - Miyase Tekpınar
- Institute of Applied Physics (APH), Karlsruhe Institute of Technology (KIT), Wolfgang Gaede-Strasse 1, 76131 Karlsruhe, Germany
| | - Karin Nienhaus
- Institute of Applied Physics (APH), Karlsruhe Institute of Technology (KIT), Wolfgang Gaede-Strasse 1, 76131 Karlsruhe, Germany
| | - Tanja Beil
- Institute of Biological and Chemical Systems (IBCS), Karlsruhe Institute of Technology (KIT), PO Box 3640, 76021 Karlsruhe, Germany
| | - Sepand Rastegar
- Institute of Biological and Chemical Systems (IBCS), Karlsruhe Institute of Technology (KIT), PO Box 3640, 76021 Karlsruhe, Germany
| | - Uwe Strähle
- Institute of Biological and Chemical Systems (IBCS), Karlsruhe Institute of Technology (KIT), PO Box 3640, 76021 Karlsruhe, Germany
- Centre for Organismal Studies (COS), Heidelberg University, Im Neuenheimer Feld 230, 69120 Heidelberg, Germany
| | - Gerd Ulrich Nienhaus
- Institute of Applied Physics (APH), Karlsruhe Institute of Technology (KIT), Wolfgang Gaede-Strasse 1, 76131 Karlsruhe, Germany
- Institute of Biological and Chemical Systems (IBCS), Karlsruhe Institute of Technology (KIT), PO Box 3640, 76021 Karlsruhe, Germany
- Institute of Nanotechnology (INT), Karlsruhe Institute of Technology (KIT), PO Box 3640, 76021 Karlsruhe, Germany
- Department of Physics, University of Illinois at Urbana−Champaign, Urbana, IL 61801, USA
| |
Collapse
|
25
|
Zhou Y, Huang M, Tian F, Shi X, Zhang X. Einstein-Stokes relation for small bubbles at the nanoscale. J Chem Phys 2024; 160:054109. [PMID: 38341701 DOI: 10.1063/5.0189490] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2023] [Accepted: 01/15/2024] [Indexed: 02/13/2024] Open
Abstract
As the physicochemical properties of ultrafine bubble systems are governed by their size, it is crucial to determine the size and distribution of such bubble systems. At present, the size or size distribution of nanometer-sized bubbles in suspension is often measured by either dynamic light scattering or the nanoparticle tracking analysis. Both techniques determine the bubble size via the Einstein-Stokes equation based on the theory of the Brownian motion. However, it is not yet clear to which extent the Einstein-Stokes equation is applicable for such ultrafine bubbles. In this work, using atomic molecular dynamics simulation, we evaluate the applicability of the Einstein-Stokes equation for gas nanobubbles with a diameter less than 10 nm, and for a comparative analysis, both vacuum nanobubbles and copper nanoparticles are also considered. The simulation results demonstrate that the diffusion coefficient for rigid nanoparticles in water is found to be highly consistent with the Einstein-Stokes equation, with slight deviation only found for nanoparticle with a radius less than 1 nm. For nanobubbles, including both methane and vacuum nanobubbles, however, large deviation from the Einstein-Stokes equation is found for the bubble radius larger than 3 nm. The deviation is attributed to the deformability of large nanobubbles that leads to a cushioning effect for collision-induced bubble diffusion.
Collapse
Affiliation(s)
- Youbin Zhou
- State Key Laboratory of Organic-Inorganic Composites, Beijing University of Chemical Technology, Beijing 100029, China
| | - Mengyuan Huang
- State Key Laboratory of Organic-Inorganic Composites, Beijing University of Chemical Technology, Beijing 100029, China
- Institute of Fluid Dynamics, Helmholtz-Zentrum Dresden-Rossendorf, Dresden 01328, Germany
| | - Falin Tian
- Laboratory of Theoretical and Computational Nanoscience, National Center for Nanoscience and Technology, Chinese Academy of Sciences, Beijing 100190, People's Republic of China
| | - Xinghua Shi
- Laboratory of Theoretical and Computational Nanoscience, National Center for Nanoscience and Technology, Chinese Academy of Sciences, Beijing 100190, People's Republic of China
| | - Xianren Zhang
- State Key Laboratory of Organic-Inorganic Composites, Beijing University of Chemical Technology, Beijing 100029, China
| |
Collapse
|
26
|
Vasyankin AV, Panteleev SV, Steshin IS, Shirokova EA, Rozhkov AV, Livshits GD, Radchenko EV, Ignatov SK, Palyulin VA. Temperature-Induced Restructuring of Mycolic Acid Bilayers Modeling the Mycobacterium tuberculosis Outer Membrane: A Molecular Dynamics Study. Molecules 2024; 29:696. [PMID: 38338443 PMCID: PMC10856651 DOI: 10.3390/molecules29030696] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2024] [Revised: 01/29/2024] [Accepted: 01/31/2024] [Indexed: 02/12/2024] Open
Abstract
The emergence of new drug-resistant strains of the tuberculosis pathogen Mycobacterium tuberculosis (Mtb) is a new challenge for modern medicine. Its resistance capacity is closely related to the properties of the outer membrane of the Mtb cell wall, which is a bilayer membrane formed by mycolic acids (MAs) and their derivatives. To date, the molecular mechanisms of the response of the Mtb outer membrane to external factors and, in particular, elevated temperatures have not been sufficiently studied. In this work, we consider the temperature-induced changes in the structure, ordering, and molecular mobility of bilayer MA membranes of various chemical and conformational compositions. Using all-atom long-term molecular dynamics simulations of various MA membranes, we report the kinetic parameters of temperature-dependent changes in the MA self-diffusion coefficients and conformational compositions, including the apparent activation energies of these processes, as well as the characteristic times of ordering changes and the features of phase transitions occurring over a wide range of elevated temperatures. Understanding these effects could be useful for the prevention of drug resistance and the development of membrane-targeting pharmaceuticals, as well as in the design of membrane-based materials.
Collapse
Affiliation(s)
- Alexander V. Vasyankin
- Department of Chemistry, Lobachevsky State University of Nizhny Novgorod, Nizhny Novgorod 603022, Russia; (A.V.V.); (S.V.P.); (I.S.S.); (E.A.S.); (A.V.R.); (G.D.L.); (E.V.R.)
| | - Sergey V. Panteleev
- Department of Chemistry, Lobachevsky State University of Nizhny Novgorod, Nizhny Novgorod 603022, Russia; (A.V.V.); (S.V.P.); (I.S.S.); (E.A.S.); (A.V.R.); (G.D.L.); (E.V.R.)
| | - Ilya S. Steshin
- Department of Chemistry, Lobachevsky State University of Nizhny Novgorod, Nizhny Novgorod 603022, Russia; (A.V.V.); (S.V.P.); (I.S.S.); (E.A.S.); (A.V.R.); (G.D.L.); (E.V.R.)
| | - Ekaterina A. Shirokova
- Department of Chemistry, Lobachevsky State University of Nizhny Novgorod, Nizhny Novgorod 603022, Russia; (A.V.V.); (S.V.P.); (I.S.S.); (E.A.S.); (A.V.R.); (G.D.L.); (E.V.R.)
| | - Alexey V. Rozhkov
- Department of Chemistry, Lobachevsky State University of Nizhny Novgorod, Nizhny Novgorod 603022, Russia; (A.V.V.); (S.V.P.); (I.S.S.); (E.A.S.); (A.V.R.); (G.D.L.); (E.V.R.)
| | - Grigory D. Livshits
- Department of Chemistry, Lobachevsky State University of Nizhny Novgorod, Nizhny Novgorod 603022, Russia; (A.V.V.); (S.V.P.); (I.S.S.); (E.A.S.); (A.V.R.); (G.D.L.); (E.V.R.)
| | - Eugene V. Radchenko
- Department of Chemistry, Lobachevsky State University of Nizhny Novgorod, Nizhny Novgorod 603022, Russia; (A.V.V.); (S.V.P.); (I.S.S.); (E.A.S.); (A.V.R.); (G.D.L.); (E.V.R.)
- Department of Chemistry, Lomonosov Moscow State University, Moscow 119991, Russia
| | - Stanislav K. Ignatov
- Department of Chemistry, Lobachevsky State University of Nizhny Novgorod, Nizhny Novgorod 603022, Russia; (A.V.V.); (S.V.P.); (I.S.S.); (E.A.S.); (A.V.R.); (G.D.L.); (E.V.R.)
| | - Vladimir A. Palyulin
- Department of Chemistry, Lobachevsky State University of Nizhny Novgorod, Nizhny Novgorod 603022, Russia; (A.V.V.); (S.V.P.); (I.S.S.); (E.A.S.); (A.V.R.); (G.D.L.); (E.V.R.)
- Department of Chemistry, Lomonosov Moscow State University, Moscow 119991, Russia
| |
Collapse
|
27
|
Hatzakis N, Kaestel-Hansen J, de Sautu M, Saminathan A, Scanavachi G, Correia R, Nielsen AJ, Bleshoey S, Boomsma W, Kirchhausen T. Deep learning assisted single particle tracking for automated correlation between diffusion and function. RESEARCH SQUARE 2024:rs.3.rs-3716053. [PMID: 38352328 PMCID: PMC10862944 DOI: 10.21203/rs.3.rs-3716053/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 02/21/2024]
Abstract
Sub-cellular diffusion in living systems reflects cellular processes and interactions. Recent advances in optical microscopy allow the tracking of this nanoscale diffusion of individual objects with an unprecedented level of precision. However, the agnostic and automated extraction of functional information from the diffusion of molecules and organelles within the sub-cellular environment, is labor-intensive and poses a significant challenge. Here we introduce DeepSPT, a deep learning framework to interpret the diffusional 2D or 3D temporal behavior of objects in a rapid and efficient manner, agnostically. Demonstrating its versatility, we have applied DeepSPT to automated mapping of the early events of viral infections, identifying distinct types of endosomal organelles, and clathrin-coated pits and vesicles with up to 95% accuracy and within seconds instead of weeks. The fact that DeepSPT effectively extracts biological information from diffusion alone illustrates that besides structure, motion encodes function at the molecular and subcellular level.
Collapse
|
28
|
Hu M, Gao W, Zhang L, Wang Y, Feng H. Transformation of Diffusion and Local Structure of CH 4 , CO 2 , SO 2 and H 2 O Mixtures in Graphene Under Wide Temperature and Pressure Range: A Molecular Dynamics Simulation Study. Chemphyschem 2024; 25:e202300851. [PMID: 38088520 DOI: 10.1002/cphc.202300851] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2023] [Revised: 12/05/2023] [Indexed: 01/11/2024]
Abstract
As a material with high specific surface area and excellent chemical stability, graphene exhibited remarkable adsorption and separation performance as well as a wide range of potential applications. The graphene layer played a significant role in influencing gas transmission. In this study, we employed molecular dynamics simulation to investigate the diffusion characteristics and local structures of a mixed system consisting of CH4 , CO2 , SO2 and H2 O. Additionally, we further examined the transformation of the behavior of these mixtures within graphene layers. The order of diffusion coefficients of the four molecules without graphene was H2 O>SO2 >CO2 ≫CH4 . However, in the double-layer graphene, the order changed to CH4 >CO2 ≫H2 O>SO2 . Higher temperatures and lower pressures were found to facilitate gas diffusion. Temperature and pressure had great effects on the local structures of CH4 , CO2 and SO2 , while their impact on H2 O was limited due to the extensive network of hydrogen bonds formed by H2 O molecules. The statistical results of average coordination number revealed that CH4 tended to aggregate with itself, whereas CO2 and SO2 exhibited a tendency to aggregate with H2 O. The graphene structure enhanced the separation and transportation of CH4 from mixed systems.
Collapse
Affiliation(s)
- Minghui Hu
- Key Laboratory of Electrochemical Energy Storage and Energy Conversion of Hainan Province Hainan Normal University, Haikou, 571158, China
| | - Wei Gao
- School of Pharmacy, Guangdong Pharmaceutical University, Guangzhou, 510006, China
| | - Lisha Zhang
- Key Laboratory of Electrochemical Energy Storage and Energy Conversion of Hainan Province Hainan Normal University, Haikou, 571158, China
| | - Yize Wang
- Key Laboratory of Electrochemical Energy Storage and Energy Conversion of Hainan Province Hainan Normal University, Haikou, 571158, China
| | - Huajie Feng
- Key Laboratory of Electrochemical Energy Storage and Energy Conversion of Hainan Province Hainan Normal University, Haikou, 571158, China
| |
Collapse
|
29
|
Umezaki U, Smith McWillams AD, Tang Z, He ZMS, Siqueira IR, Corr SJ, Ryu H, Kolomeisky AB, Pasquali M, Martí AA. Brownian Diffusion of Hexagonal Boron Nitride Nanosheets and Graphene in Two Dimensions. ACS NANO 2024; 18:2446-2454. [PMID: 38207242 DOI: 10.1021/acsnano.3c11053] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/13/2024]
Abstract
Two-dimensional (2D) nanomaterials have numerous interesting chemical and physical properties that make them desirable building blocks for the manufacture of macroscopic materials. Liquid-phase processing is a common method for forming macroscopic materials from these building blocks including wet-spinning and vacuum filtration. As such, assembling 2D nanomaterials into ordered functional materials requires an understanding of their solution dynamics. Yet, there are few experimental studies investigating the hydrodynamics of disk-like materials. Herein, we report the lateral diffusion of hexagonal boron nitride nanosheets (h-BN and graphene) in aqueous solution when confined in 2-dimensions. This was done by imaging fluorescent surfactant-tagged nanosheets and visualizing them by using fluorescence microscopy. Spectroscopic studies were conducted to characterize the interactions between h-BN and the fluorescent surfactant, and atomic force microscopy (AFM) was conducted to characterize the quality of the dispersion. The diffusion data under different gap sizes and viscosities displayed a good correlation with Kramers' theory. We propose that the yielded activation energies by Kramers' equation express the magnitude of the interaction between fluorescent surfactant tagged h-BN and glass because the energies remain constant with changing viscosity and decrease with increasing confinement size. The diffusion of graphene presented a similar trend with similar activation energy as the h-BN. This relationship suggests that Kramers' theory can also be applied to simulate the diffusion of other 2D nanomaterials.
Collapse
Affiliation(s)
- Utana Umezaki
- Department of Chemistry, Rice University, Houston, Texas 77005, United States
| | | | - Zhao Tang
- Department of Chemical and Biomolecular Engineering, Rice University, Houston, Texas 77005, United States
| | - Zhi Mei Sonia He
- Department of Chemistry, Rice University, Houston, Texas 77005, United States
| | - Ivan R Siqueira
- Department of Chemical and Biomolecular Engineering, Rice University, Houston, Texas 77005, United States
| | - Stuart J Corr
- Department of Cardiovascular Surgery, Houston Methodist Hospital, Houston, Texas 77030, United States
- Department of Bioengineering, Rice University, Houston, Texas 77005, United States
| | - Hijun Ryu
- Department of Chemistry, Rice University, Houston, Texas 77005, United States
| | | | - Matteo Pasquali
- Department of Chemistry, Rice University, Houston, Texas 77005, United States
- Department of Chemical and Biomolecular Engineering, Rice University, Houston, Texas 77005, United States
- Department of Materials Science & Nanoengineering, Rice University, Houston, Texas 77005, United States
| | - Angel A Martí
- Department of Chemistry, Rice University, Houston, Texas 77005, United States
- Department of Bioengineering, Rice University, Houston, Texas 77005, United States
- Department of Materials Science & Nanoengineering, Rice University, Houston, Texas 77005, United States
| |
Collapse
|
30
|
Lebedenko OO, Salikov VA, Izmailov SA, Podkorytov IS, Skrynnikov NR. Using NMR diffusion data to validate MD models of disordered proteins: Test case of N-terminal tail of histone H4. Biophys J 2024; 123:80-100. [PMID: 37990496 PMCID: PMC10808029 DOI: 10.1016/j.bpj.2023.11.020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2023] [Revised: 10/28/2023] [Accepted: 11/17/2023] [Indexed: 11/23/2023] Open
Abstract
MD simulations can provide uniquely detailed models of intrinsically disordered proteins (IDPs). However, these models need careful experimental validation. The coefficient of translational diffusion Dtr, measurable by pulsed field gradient NMR, offers a potentially useful piece of experimental information related to the compactness of the IDP's conformational ensemble. Here, we investigate, both experimentally and via the MD modeling, the translational diffusion of a 25-residue N-terminal fragment from histone H4 (N-H4). We found that the predicted values of Dtr, as obtained from mean-square displacement of the peptide in the MD simulations, are largely determined by the viscosity of the MD water (which has been reinvestigated as a part of our study). Beyond that, our analysis of the diffusion data indicates that MD simulations of N-H4 in the TIP4P-Ew water give rise to an overly compact conformational ensemble for this peptide. In contrast, TIP4P-D and OPC simulations produce the ensembles that are consistent with the experimental Dtr result. These observations are supported by the analyses of the 15N spin relaxation rates. We also tested a number of empirical methods to predict Dtr based on IDP's coordinates extracted from the MD snapshots. In particular, we show that the popular approach involving the program HYDROPRO can produce misleading results. This happens because HYDROPRO is not intended to predict the diffusion properties of highly flexible biopolymers such as IDPs. Likewise, recent empirical schemes that exploit the relationship between the small-angle x-ray scattering-informed conformational ensembles of IDPs and the respective experimental Dtr values also prove to be problematic. In this sense, the first-principle calculations of Dtr from the MD simulations, such as demonstrated in this work, should provide a useful benchmark for future efforts in this area.
Collapse
Affiliation(s)
- Olga O Lebedenko
- Laboratory of Biomolecular NMR, St. Petersburg State University, St. Petersburg, Russia
| | - Vladislav A Salikov
- Laboratory of Biomolecular NMR, St. Petersburg State University, St. Petersburg, Russia
| | - Sergei A Izmailov
- Laboratory of Biomolecular NMR, St. Petersburg State University, St. Petersburg, Russia
| | - Ivan S Podkorytov
- Laboratory of Biomolecular NMR, St. Petersburg State University, St. Petersburg, Russia
| | - Nikolai R Skrynnikov
- Laboratory of Biomolecular NMR, St. Petersburg State University, St. Petersburg, Russia; Department of Chemistry, Purdue University, West Lafayette, Indiana.
| |
Collapse
|
31
|
Rusch R, Franosch T, Jung G. Noise-cancellation algorithm for simulations of Brownian particles. Phys Rev E 2024; 109:015303. [PMID: 38366417 DOI: 10.1103/physreve.109.015303] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2023] [Accepted: 12/12/2023] [Indexed: 02/18/2024]
Abstract
We investigate the usage of a recently introduced noise-cancellation algorithm for Brownian simulations to enhance the precision of measuring transport properties such as the mean-square displacement or the velocity-autocorrelation function. The algorithm is based on explicitly storing the pseudorandom numbers used to create the randomized displacements in computer simulations and subtracting them from the simulated trajectories. The resulting correlation function of the reduced motion is connected to the target correlation function up to a cross-correlation term. Using analytical theory and computer simulations, we demonstrate that the cross-correlation term can be neglected in all three systems studied in this paper. We further expand the algorithm to Monte Carlo simulations and analyze the performance of the algorithm and rationalize that it works particularly well for unbounded, weakly interacting systems in which the precision of the mean-square displacement can be improved by orders of magnitude.
Collapse
Affiliation(s)
- Regina Rusch
- Institut für Theoretische Physik, Technikerstraße 21-A, Universität Innsbruck, A-6020 Innsbruck, Austria
| | - Thomas Franosch
- Institut für Theoretische Physik, Technikerstraße 21-A, Universität Innsbruck, A-6020 Innsbruck, Austria
| | - Gerhard Jung
- Laboratoire Charles Coulomb (L2C), Université de Montpellier, Centre National de la Recherche Scientifique, 34095 Montpellier, France
| |
Collapse
|
32
|
Loseva E, van Krugten J, Mitra A, Peterman EJG. Single-Molecule Fluorescence Microscopy in Sensory Cilia of Living Caenorhabditis elegans. Methods Mol Biol 2024; 2694:133-150. [PMID: 37824003 DOI: 10.1007/978-1-0716-3377-9_7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/13/2023]
Abstract
Intracellular transport of organelles and biomolecules is vital for several cellular processes. Single-molecule fluorescence microscopy can illuminate molecular aspects of the dynamics of individual biomolecules that remain unresolved in ensemble experiments. For example, studying single-molecule trajectories of moving biomolecules can reveal motility properties such as velocity, diffusivity, location and duration of pauses, etc. We use single-molecule imaging to study the dynamics of microtubule-based motor proteins and their cargo in the primary cilia of living C. elegans. To this end, we employ standard fluorescent proteins, an epi-illuminated, widefield fluorescence microscope, and primarily open-source software. This chapter describes the setup we use, the preparation of samples, a protocol for single-molecule imaging in primary cilia of C. elegans, and data analysis.
Collapse
Affiliation(s)
- Elizaveta Loseva
- LaserLaB Amsterdam and Department of Physics and Astronomy, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands
| | - Jaap van Krugten
- LaserLaB Amsterdam and Department of Physics and Astronomy, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands
| | - Aniruddha Mitra
- LaserLaB Amsterdam and Department of Physics and Astronomy, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands
| | - Erwin J G Peterman
- LaserLaB Amsterdam and Department of Physics and Astronomy, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands.
| |
Collapse
|
33
|
Sharma V, Fessler F, Thalmann F, Marques CM, Stocco A. Rotational and translational drags of a Janus particle close to a wall and a lipid membrane. J Colloid Interface Sci 2023; 652:2159-2166. [PMID: 37713952 DOI: 10.1016/j.jcis.2023.09.026] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2023] [Revised: 09/01/2023] [Accepted: 09/04/2023] [Indexed: 09/17/2023]
Abstract
HYPOTHESIS Measuring rotational and translational Brownian motion of single spherical particles reveals dissipations due to the interaction between the particle and the environment. EXPERIMENTS In this article, we show experiments where the in-plane translational and the two rotational drag coefficients of a single spherical Brownian particle can be measured. These particle drags are functions of the particle size and of the particle-wall distance, and of the viscous dissipations at play. We measure drag coefficients for Janus particles close to a solid wall and close to a lipid bilayer membrane. FINDINGS For a particle close to a wall, we show that according to hydrodynamic models, particle-wall distance and particle size can be determined. For a particle partially wrapped by lipid membranes, in absence of strong binding interactions, translational and rotational drags are significantly larger than the ones of non-wrapped particles. Beside the effect of the membrane viscosity, we show that dissipations in the deformed membrane cap region strongly contribute to the drag coefficients.
Collapse
Affiliation(s)
- Vaibhav Sharma
- Institut Charles Sadron, CNRS UPR22-University of Strasbourg, 23 rue du Loess, Strasbourg 67034, France
| | - Florent Fessler
- Institut Charles Sadron, CNRS UPR22-University of Strasbourg, 23 rue du Loess, Strasbourg 67034, France
| | - Fabrice Thalmann
- Institut Charles Sadron, CNRS UPR22-University of Strasbourg, 23 rue du Loess, Strasbourg 67034, France
| | - Carlos M Marques
- ENS Lyon, CNRS, Université Lyon 1, Laboratoire de Chimie UMR 5182, F-69342 Lyon, France
| | - Antonio Stocco
- Institut Charles Sadron, CNRS UPR22-University of Strasbourg, 23 rue du Loess, Strasbourg 67034, France.
| |
Collapse
|
34
|
Kæstel-Hansen J, de Sautu M, Saminathan A, Scanavachi G, Da Cunha Correia RFB, Nielsen AJ, Bleshøy SV, Boomsma W, Kirchhausen T, Hatzakis NS. Deep learning assisted single particle tracking for automated correlation between diffusion and function. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.11.16.567393. [PMID: 38014323 PMCID: PMC10680793 DOI: 10.1101/2023.11.16.567393] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/29/2023]
Abstract
Sub-cellular diffusion in living systems reflects cellular processes and interactions. Recent advances in optical microscopy allow the tracking of this nanoscale diffusion of individual objects with an unprecedented level of precision. However, the agnostic and automated extraction of functional information from the diffusion of molecules and organelles within the sub-cellular environment, is labor-intensive and poses a significant challenge. Here we introduce DeepSPT, a deep learning framework to interpret the diffusional 2D or 3D temporal behavior of objects in a rapid and efficient manner, agnostically. Demonstrating its versatility, we have applied DeepSPT to automated mapping of the early events of viral infections, identifying distinct types of endosomal organelles, and clathrin-coated pits and vesicles with up to 95% accuracy and within seconds instead of weeks. The fact that DeepSPT effectively extracts biological information from diffusion alone indicates that besides structure, motion encodes function at the molecular and subcellular level.
Collapse
Affiliation(s)
- Jacob Kæstel-Hansen
- Department of Chemistry University of Copenhagen
- Center for 4D cellular dynamics, Department of Chemistry University of Copenhagen
- Novo Nordisk Center for Optimised Oligo Escape
- Novo Nordisk foundation Center for Protein Research
| | - Marilina de Sautu
- Biological Chemistry and Molecular Pharmaceutics Harvard Medical School
- Laboratory of Molecular Medicine Boston Children's Hospital
| | - Anand Saminathan
- Department of Cell Biology Harvard Medical School
- Department of Pediatrics Harvard Medical School
- Program in Cellular and Molecular Medicine Boston Children's Hospital
| | - Gustavo Scanavachi
- Department of Cell Biology Harvard Medical School
- Department of Pediatrics Harvard Medical School
- Program in Cellular and Molecular Medicine Boston Children's Hospital
| | - Ricardo F Bango Da Cunha Correia
- Department of Cell Biology Harvard Medical School
- Department of Pediatrics Harvard Medical School
- Program in Cellular and Molecular Medicine Boston Children's Hospital
| | - Annette Juma Nielsen
- Department of Chemistry University of Copenhagen
- Center for 4D cellular dynamics, Department of Chemistry University of Copenhagen
- Novo Nordisk Center for Optimised Oligo Escape
- Novo Nordisk foundation Center for Protein Research
| | - Sara Vogt Bleshøy
- Department of Chemistry University of Copenhagen
- Center for 4D cellular dynamics, Department of Chemistry University of Copenhagen
- Novo Nordisk Center for Optimised Oligo Escape
- Novo Nordisk foundation Center for Protein Research
| | | | - Tom Kirchhausen
- Department of Cell Biology Harvard Medical School
- Department of Pediatrics Harvard Medical School
- Program in Cellular and Molecular Medicine Boston Children's Hospital
| | - Nikos S Hatzakis
- Department of Chemistry University of Copenhagen
- Center for 4D cellular dynamics, Department of Chemistry University of Copenhagen
- Novo Nordisk Center for Optimised Oligo Escape
- Novo Nordisk foundation Center for Protein Research
| |
Collapse
|
35
|
Yavuz S, Kabbech H, van Staalduinen J, Linder S, van Cappellen W, Nigg A, Abraham T, Slotman J, Quevedo M, Poot R, Zwart W, van Royen M, Grosveld F, Smal I, Houtsmuller A. Compartmentalization of androgen receptors at endogenous genes in living cells. Nucleic Acids Res 2023; 51:10992-11009. [PMID: 37791849 PMCID: PMC10639085 DOI: 10.1093/nar/gkad803] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2023] [Revised: 09/06/2023] [Accepted: 09/20/2023] [Indexed: 10/05/2023] Open
Abstract
A wide range of nuclear proteins are involved in the spatio-temporal organization of the genome through diverse biological processes such as gene transcription and DNA replication. Upon stimulation by testosterone and translocation to the nucleus, multiple androgen receptors (ARs) accumulate in microscopically discernable foci which are irregularly distributed in the nucleus. Here, we investigated the formation and physical nature of these foci, by combining novel fluorescent labeling techniques to visualize a defined chromatin locus of AR-regulated genes-PTPRN2 or BANP-simultaneously with either AR foci or individual AR molecules. Quantitative colocalization analysis showed evidence of AR foci formation induced by R1881 at both PTPRN2 and BANP loci. Furthermore, single-particle tracking (SPT) revealed three distinct subdiffusive fractional Brownian motion (fBm) states: immobilized ARs were observed near the labeled genes likely as a consequence of DNA-binding, while the intermediate confined state showed a similar spatial behavior but with larger displacements, suggesting compartmentalization by liquid-liquid phase separation (LLPS), while freely mobile ARs were diffusing in the nuclear environment. All together, we show for the first time in living cells the presence of AR-regulated genes in AR foci.
Collapse
Affiliation(s)
- Selçuk Yavuz
- Department of Pathology, Erasmus University Medical Center, Rotterdam, The Netherlands
| | - Hélène Kabbech
- Department of Cell Biology, Erasmus University Medical Center, Rotterdam, The Netherlands
| | - Jente van Staalduinen
- Department of Cell Biology, Erasmus University Medical Center, Rotterdam, The Netherlands
| | - Simon Linder
- Division of Oncogenomics, The Netherlands Cancer Institute, Amsterdam, The Netherlands
| | - Wiggert A van Cappellen
- Erasmus Optical Imaging Center, Erasmus University Medical Center, Rotterdam, The Netherlands
| | - Alex L Nigg
- Erasmus Optical Imaging Center, Erasmus University Medical Center, Rotterdam, The Netherlands
| | - Tsion E Abraham
- Erasmus Optical Imaging Center, Erasmus University Medical Center, Rotterdam, The Netherlands
| | - Johan A Slotman
- Erasmus Optical Imaging Center, Erasmus University Medical Center, Rotterdam, The Netherlands
| | - Marti Quevedo
- Department of Cell Biology, Erasmus University Medical Center, Rotterdam, The Netherlands
| | - Raymond A Poot
- Department of Cell Biology, Erasmus University Medical Center, Rotterdam, The Netherlands
| | - Wilbert Zwart
- Division of Oncogenomics, The Netherlands Cancer Institute, Amsterdam, The Netherlands
- Laboratory of Chemical Biology and Institute for Complex Molecular Systems, Department of Biomedical Engineering, Eindhoven University of Technology, Eindhoven, The Netherlands
| | - Martin E van Royen
- Department of Pathology, Erasmus University Medical Center, Rotterdam, The Netherlands
| | - Frank G Grosveld
- Department of Cell Biology, Erasmus University Medical Center, Rotterdam, The Netherlands
| | - Ihor Smal
- Department of Cell Biology, Erasmus University Medical Center, Rotterdam, The Netherlands
| | - Adriaan B Houtsmuller
- Department of Pathology, Erasmus University Medical Center, Rotterdam, The Netherlands
- Erasmus Optical Imaging Center, Erasmus University Medical Center, Rotterdam, The Netherlands
| |
Collapse
|
36
|
Waigh TA, Korabel N. Heterogeneous anomalous transport in cellular and molecular biology. REPORTS ON PROGRESS IN PHYSICS. PHYSICAL SOCIETY (GREAT BRITAIN) 2023; 86:126601. [PMID: 37863075 DOI: 10.1088/1361-6633/ad058f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/21/2022] [Accepted: 10/20/2023] [Indexed: 10/22/2023]
Abstract
It is well established that a wide variety of phenomena in cellular and molecular biology involve anomalous transport e.g. the statistics for the motility of cells and molecules are fractional and do not conform to the archetypes of simple diffusion or ballistic transport. Recent research demonstrates that anomalous transport is in many cases heterogeneous in both time and space. Thus single anomalous exponents and single generalised diffusion coefficients are unable to satisfactorily describe many crucial phenomena in cellular and molecular biology. We consider advances in the field ofheterogeneous anomalous transport(HAT) highlighting: experimental techniques (single molecule methods, microscopy, image analysis, fluorescence correlation spectroscopy, inelastic neutron scattering, and nuclear magnetic resonance), theoretical tools for data analysis (robust statistical methods such as first passage probabilities, survival analysis, different varieties of mean square displacements, etc), analytic theory and generative theoretical models based on simulations. Special emphasis is made on high throughput analysis techniques based on machine learning and neural networks. Furthermore, we consider anomalous transport in the context of microrheology and the heterogeneous viscoelasticity of complex fluids. HAT in the wavefronts of reaction-diffusion systems is also considered since it plays an important role in morphogenesis and signalling. In addition, we present specific examples from cellular biology including embryonic cells, leucocytes, cancer cells, bacterial cells, bacterial biofilms, and eukaryotic microorganisms. Case studies from molecular biology include DNA, membranes, endosomal transport, endoplasmic reticula, mucins, globular proteins, and amyloids.
Collapse
Affiliation(s)
- Thomas Andrew Waigh
- Biological Physics, School of Physics and Astronomy, University of Manchester, Manchester M13 9PL, United Kingdom
| | - Nickolay Korabel
- Department of Mathematics, The University of Manchester, Manchester M13 9PL, United Kingdom
| |
Collapse
|
37
|
Ali A, Garde R, Schaffer OC, Bard JAM, Husain K, Kik SK, Davis KA, Luengo-Woods S, Igarashi MG, Drummond DA, Squires AH, Pincus D. Adaptive preservation of orphan ribosomal proteins in chaperone-dispersed condensates. Nat Cell Biol 2023; 25:1691-1703. [PMID: 37845327 PMCID: PMC10868727 DOI: 10.1038/s41556-023-01253-2] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2022] [Accepted: 09/12/2023] [Indexed: 10/18/2023]
Abstract
Ribosome biogenesis is among the most resource-intensive cellular processes, with ribosomal proteins accounting for up to half of all newly synthesized proteins in eukaryotic cells. During stress, cells shut down ribosome biogenesis in part by halting rRNA synthesis, potentially leading to massive accumulation of aggregation-prone 'orphan' ribosomal proteins (oRPs). Here we show that, during heat shock in yeast and human cells, oRPs accumulate as reversible peri-nucleolar condensates recognized by the Hsp70 co-chaperone Sis1/DnaJB6. oRP condensates are liquid-like in cell-free lysate but solidify upon depletion of Sis1 or inhibition of Hsp70. When cells recover from heat shock, oRP condensates disperse in a Sis1- and Hsp70-dependent manner, and the oRP constituents are incorporated into functional ribosomes in the cytosol, enabling cells to efficiently resume growth. Preserving biomolecules in reversible condensates-like mRNAs in cytosolic stress granules and oRPs at the nucleolar periphery-may be a primary function of the Hsp70 chaperone system.
Collapse
Affiliation(s)
- Asif Ali
- Department of Molecular Genetics and Cell Biology, University of Chicago, Chicago, IL, USA.
| | - Rania Garde
- Department of Molecular Genetics and Cell Biology, University of Chicago, Chicago, IL, USA
- Committee on Genetics, Genomics, and Systems Biology, University of Chicago, Chicago, IL, USA
| | - Olivia C Schaffer
- Pritzker School for Molecular Engineering, University of Chicago, Chicago, IL, USA
| | - Jared A M Bard
- Department of Biochemistry and Molecular Biology, University of Chicago, Chicago, IL, USA
| | - Kabir Husain
- Department of Physics, University of Chicago, Chicago, IL, USA
| | - Samantha Keyport Kik
- Committee on Genetics, Genomics, and Systems Biology, University of Chicago, Chicago, IL, USA
- Department of Biochemistry and Molecular Biology, University of Chicago, Chicago, IL, USA
| | - Kathleen A Davis
- Department of Molecular Genetics and Cell Biology, University of Chicago, Chicago, IL, USA
| | - Sofia Luengo-Woods
- Department of Molecular Genetics and Cell Biology, University of Chicago, Chicago, IL, USA
| | - Maya G Igarashi
- Graduate Program in Biophysical Sciences, University of Chicago, Chicago, IL, USA
| | - D Allan Drummond
- Department of Biochemistry and Molecular Biology, University of Chicago, Chicago, IL, USA
- Department of Medicine, Section of Genetic Medicine, University of Chicago, Chicago, IL, USA
- Institute for Biophysical Dynamics, University of Chicago, Chicago, IL, USA
- Center for Physics of Evolving Systems, University of Chicago, Chicago, IL, USA
| | - Allison H Squires
- Pritzker School for Molecular Engineering, University of Chicago, Chicago, IL, USA
- Institute for Biophysical Dynamics, University of Chicago, Chicago, IL, USA
- Center for Physics of Evolving Systems, University of Chicago, Chicago, IL, USA
| | - David Pincus
- Department of Molecular Genetics and Cell Biology, University of Chicago, Chicago, IL, USA.
- Institute for Biophysical Dynamics, University of Chicago, Chicago, IL, USA.
- Center for Physics of Evolving Systems, University of Chicago, Chicago, IL, USA.
| |
Collapse
|
38
|
Sánchez H, Liu Z, van Veen E, van Laar T, Diffley JFX, Dekker NH. A chromatinized origin reduces the mobility of ORC and MCM through interactions and spatial constraint. Nat Commun 2023; 14:6735. [PMID: 37872142 PMCID: PMC10593741 DOI: 10.1038/s41467-023-42524-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2023] [Accepted: 10/13/2023] [Indexed: 10/25/2023] Open
Abstract
Chromatin replication involves the assembly and activity of the replisome within the nucleosomal landscape. At the core of the replisome is the Mcm2-7 complex (MCM), which is loaded onto DNA after binding to the Origin Recognition Complex (ORC). In yeast, ORC is a dynamic protein that diffuses rapidly along DNA, unless halted by origin recognition sequences. However, less is known about the dynamics of ORC proteins in the presence of nucleosomes and attendant consequences for MCM loading. To address this, we harnessed an in vitro single-molecule approach to interrogate a chromatinized origin of replication. We find that ORC binds the origin of replication with similar efficiency independently of whether the origin is chromatinized, despite ORC mobility being reduced by the presence of nucleosomes. Recruitment of MCM also proceeds efficiently on a chromatinized origin, but subsequent movement of MCM away from the origin is severely constrained. These findings suggest that chromatinized origins in yeast are essential for the local retention of MCM, which may facilitate subsequent assembly of the replisome.
Collapse
Affiliation(s)
- Humberto Sánchez
- Department of Bionanoscience, Kavli Institute of Nanoscience, Delft University of Technology, Delft, The Netherlands
| | - Zhaowei Liu
- Department of Bionanoscience, Kavli Institute of Nanoscience, Delft University of Technology, Delft, The Netherlands
| | - Edo van Veen
- Department of Bionanoscience, Kavli Institute of Nanoscience, Delft University of Technology, Delft, The Netherlands
| | - Theo van Laar
- Department of Bionanoscience, Kavli Institute of Nanoscience, Delft University of Technology, Delft, The Netherlands
| | - John F X Diffley
- Chromosome Replication Laboratory, Francis Crick Institute, London, United Kingdom
| | - Nynke H Dekker
- Department of Bionanoscience, Kavli Institute of Nanoscience, Delft University of Technology, Delft, The Netherlands.
| |
Collapse
|
39
|
Ta DM, Aguilar A, Bon P. Label-free image scanning microscopy for kHz super-resolution imaging and single particle tracking. OPTICS EXPRESS 2023; 31:36420-36428. [PMID: 38017795 DOI: 10.1364/oe.504581] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/30/2023] [Accepted: 10/02/2023] [Indexed: 11/30/2023]
Abstract
We report the modification of a label-free image scanning microscope (ISM) to perform asynchronous 2D imaging at up to 24kHz while keeping the lateral resolution gain and background rejection of a regular label-free ISM setup. Our method uses a resonant mirror oscillating at 12kHz for one-direction scanning and a chromatic line for instantaneous scanning in the other direction. We adapt optical photon reassignment in this scanning regime to perform fully optical super-resolution imaging. We exploit the kHz imaging capabilities of this confocal imaging system for single nanoparticle tracking down to 20 nm for gold and 50 nm for silica particles as well as imaging freely moving Lactobacillus with improved resolution.
Collapse
|
40
|
DIBAJI HASSAN, SHOTORBAN ALIKAZEMINASABAN, HABIBI MAHSA, GRATTAN RACHELM, LUCERO SHAYNA, SCHODT DAVIDJ, LIDKE KEITHA, PETRUCCELLI JONATHAN, LIDKE DIANES, LIU SHENG, CHAKRABORTY TONMOY. Axial de-scanning using remote focusing in the detection arm of light-sheet microscopy. RESEARCH SQUARE 2023:rs.3.rs-3338831. [PMID: 37886461 PMCID: PMC10602066 DOI: 10.21203/rs.3.rs-3338831/v1] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/28/2023]
Abstract
The ability to image at high speeds is necessary in biological imaging to capture fast-moving or transient events or to efficiently image large samples. However, due to the lack of rigidity of biological specimens, carrying out fast, high-resolution volumetric imaging without moving and agitating the sample has been a challenging problem. Pupil-matched remote focusing has been promising for high NA imaging systems with their low aberrations and wavelength independence, making it suitable for multicolor imaging. However, owing to the incoherent and unpolarized nature of the fluorescence signal, manipulating this emission light through remote focusing is challenging. Therefore, remote focusing has been primarily limited to the illumination arm, using polarized laser light for facilitating coupling in and out of the remote focusing optics. Here we introduce a novel optical design that can de-scan the axial focus movement in the detection arm of a microscope. Our method splits the fluorescence signal into S and P-polarized light and lets them pass through the remote focusing module separately and combines them with the camera. This allows us to use only one focusing element to perform aberration-free, multi-color, volumetric imaging without (a) compromising the fluorescent signal and (b) needing to perform sample/detection-objective translation. We demonstrate the capabilities of this scheme by acquiring fast dual-color 4D (3D space + time) image stacks, with an axial range of 70 μm and camera limited acquisition speed. Owing to its general nature, we believe this technique will find its application to many other microscopy techniques that currently use an adjustable Z-stage to carry out volumetric imaging such as confocal, 2-photon, and light sheet variants.
Collapse
Affiliation(s)
- HASSAN DIBAJI
- Department of Physics and Astronomy, University of New Mexico, Albuquerque, New Mexico 87131, USA
| | | | - MAHSA HABIBI
- Department of Physics and Astronomy, University of New Mexico, Albuquerque, New Mexico 87131, USA
| | - RACHEL M GRATTAN
- Comprehensive Cancer Center, University of New Mexico Health Sciences Center, Albuquerque, New Mexico, 87131, USA
- Department of Pathology, University of New Mexico Health Science Center, Albuquerque, NM, USA
| | - SHAYNA LUCERO
- Comprehensive Cancer Center, University of New Mexico Health Sciences Center, Albuquerque, New Mexico, 87131, USA
- Department of Pathology, University of New Mexico Health Science Center, Albuquerque, NM, USA
| | - DAVID J. SCHODT
- Department of Physics and Astronomy, University of New Mexico, Albuquerque, New Mexico 87131, USA
| | - KEITH A. LIDKE
- Department of Physics and Astronomy, University of New Mexico, Albuquerque, New Mexico 87131, USA
- Comprehensive Cancer Center, University of New Mexico Health Sciences Center, Albuquerque, New Mexico, 87131, USA
| | - JONATHAN PETRUCCELLI
- Department of Physics, University at Albany–State University of NewYork,1400 Washington Avenue, Albany, NY 12222, USA
| | - DIANE S. LIDKE
- Comprehensive Cancer Center, University of New Mexico Health Sciences Center, Albuquerque, New Mexico, 87131, USA
- Department of Pathology, University of New Mexico Health Science Center, Albuquerque, NM, USA
| | - SHENG LIU
- Department of Physics and Astronomy, University of New Mexico, Albuquerque, New Mexico 87131, USA
| | - TONMOY CHAKRABORTY
- Department of Physics and Astronomy, University of New Mexico, Albuquerque, New Mexico 87131, USA
- Comprehensive Cancer Center, University of New Mexico Health Sciences Center, Albuquerque, New Mexico, 87131, USA
| |
Collapse
|
41
|
Alhaddad S, Bey H, Thouvenin O, Boulanger P, Boccara C, Boccara M, Izeddin I. Real-time detection of virus antibody interaction by label-free common-path interferometry. BIOPHYSICAL REPORTS 2023; 3:100119. [PMID: 37662577 PMCID: PMC10470184 DOI: 10.1016/j.bpr.2023.100119] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/27/2023] [Accepted: 07/27/2023] [Indexed: 09/05/2023]
Abstract
Viruses have a profound influence on all forms of life, motivating the development of rapid and minimally invasive methods for virus detection. In this study, we present a novel methodology that enables quantitative measurement of the interaction between individual biotic nanoparticles and antibodies in solution. Our approach employs a label-free, full-field common-path interferometric technique to detect and track biotic nanoparticles and their interactions with antibodies. It is based on the interferometric detection of light scattered by viruses in aqueous samples for the detection of individual viruses. We employ single-particle tracking analysis to characterize the size and properties of the detected nanoparticles, and to monitor the changes in their diffusive mobility resulting from interactions. To validate the sensitivity of our detection approach, we distinguish between particles having identical diffusion coefficients but different scattering signals, using DNA-loaded and DNA-devoid capsids of the Escherichia coli T5 virus phage. In addition, we have been able to monitor, in real time, the interaction between the bacteriophage T5 and purified antibodies targeting its major capsid protein pb8, as well as between the phage SPP1 and nonpurified anti-SPP1 antibodies present in rabbit serum. Interestingly, these virus-antibody interactions are observed within minutes. Finally, by estimating the number of viral particles interacting with antibodies at different concentrations, we successfully quantify the dissociation constant K d of the virus-antibody reaction using single-particle tracking analysis.
Collapse
Affiliation(s)
- Samer Alhaddad
- Institut Langevin, ESPCI Paris, CNRS, PSL University, Paris, France
| | - Houda Bey
- Institut Langevin, ESPCI Paris, CNRS, PSL University, Paris, France
| | | | - Pascale Boulanger
- Institut de Biologie Intégrative de la Cellule, Université Paris-Saclay, CNRS, CEA, Orsay, France
| | - Claude Boccara
- Institut Langevin, ESPCI Paris, CNRS, PSL University, Paris, France
| | - Martine Boccara
- Institut Langevin, ESPCI Paris, CNRS, PSL University, Paris, France
- Institut de Biologie de l’ENS, CNRS, Inserm, Paris, France
| | - Ignacio Izeddin
- Institut Langevin, ESPCI Paris, CNRS, PSL University, Paris, France
| |
Collapse
|
42
|
Fournier M, Leclerc P, Leray A, Champelovier D, Agbazahou F, Dahmani F, Bidaux G, Furlan A, Héliot L. Combined SPT and FCS methods reveal a mechanism of RNAP II oversampling in cell nuclei. Sci Rep 2023; 13:14633. [PMID: 37669988 PMCID: PMC10480184 DOI: 10.1038/s41598-023-38668-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2023] [Accepted: 07/12/2023] [Indexed: 09/07/2023] Open
Abstract
Gene expression orchestration is a key question in fundamental and applied research. Different models for transcription regulation were proposed, yet the dynamic regulation of RNA polymerase II (RNAP II) activity remains a matter of debate. To improve our knowledge of this topic, we investigated RNAP II motility in eukaryotic cells by combining single particle tracking (SPT) and fluorescence correlation spectroscopy (FCS) techniques, to take advantage of their different sensitivities in order to analyze together slow and fast molecular movements. Thanks to calibrated samples, we developed a benchmark for quantitative analysis of molecular dynamics, to eliminate the main potential instrumental biases. We applied this workflow to study the diffusion of RPB1, the catalytic subunit of RNAP II. By a cross-analysis of FCS and SPT, we could highlight different RPB1 motility states and identifyed a stationary state, a slow diffusion state, and two different modes of subdiffusion. Interestingly, our analysis also unveiled the oversampling by RPB1 of nuclear subdomains. Based on these data, we propose a novel model of spatio-temporal transcription regulation. Altogether, our results highlight the importance of combining microscopy approaches at different time scales to get a full insight into the real complexity of molecular kinetics in cells.
Collapse
Affiliation(s)
- Marie Fournier
- Univ. Lille, CNRS, UMR 8523, PhLAM Laboratoire de Physique des Lasers, Atomes et Molécules, Lille, France
- CNRS, Groupement de Recherche ImaBio, 59655, Villeneuve d'Ascq, France
| | - Pierre Leclerc
- Univ. Lille, CNRS, UMR 8523, PhLAM Laboratoire de Physique des Lasers, Atomes et Molécules, Lille, France
- CNRS, Groupement de Recherche ImaBio, 59655, Villeneuve d'Ascq, France
| | - Aymeric Leray
- Laboratoire Interdisciplinaire Carnot de Bourgogne, UMR 6303 CNRS, Université de Bourgogne Franche Comte, Dijon, France
- CNRS, Groupement de Recherche ImaBio, 59655, Villeneuve d'Ascq, France
| | - Dorian Champelovier
- Univ. Lille, CNRS, UMR 8523, PhLAM Laboratoire de Physique des Lasers, Atomes et Molécules, Lille, France
- CNRS, Groupement de Recherche ImaBio, 59655, Villeneuve d'Ascq, France
| | - Florence Agbazahou
- Univ. Lille, CNRS, UMR 8523, PhLAM Laboratoire de Physique des Lasers, Atomes et Molécules, Lille, France
- CNRS, Groupement de Recherche ImaBio, 59655, Villeneuve d'Ascq, France
| | - Fatima Dahmani
- Univ. Lille, CNRS, UMR 8523, PhLAM Laboratoire de Physique des Lasers, Atomes et Molécules, Lille, France
- CNRS, Groupement de Recherche ImaBio, 59655, Villeneuve d'Ascq, France
| | - Gabriel Bidaux
- INSERM UMR 1060, CarMeN Laboratory, IHU OPERA, Hôpital Louis Pradel, Hospices Civils de Lyon, Univ Lyon1, Lyon, France
- CNRS, Groupement de Recherche ImaBio, 59655, Villeneuve d'Ascq, France
| | - Alessandro Furlan
- Univ. Lille, CNRS, UMR 8523, PhLAM Laboratoire de Physique des Lasers, Atomes et Molécules, Lille, France.
- Univ. Lille, CNRS, Inserm, CHU Lille, UMR9020-U1277 -CANTHER -Cancer Heterogeneity Plasticity and Resistance to Therapies, Lille, 59000, France.
- Unité Tumorigenèse et Résistance aux Traitements, Centre Oscar Lambret, 59000, Lille, France.
- CNRS, Groupement de Recherche ImaBio, 59655, Villeneuve d'Ascq, France.
| | - Laurent Héliot
- Univ. Lille, CNRS, UMR 8523, PhLAM Laboratoire de Physique des Lasers, Atomes et Molécules, Lille, France.
- CNRS, Groupement de Recherche ImaBio, 59655, Villeneuve d'Ascq, France.
| |
Collapse
|
43
|
Prindle JR, de Cuba OIC, Gahlmann A. Single-molecule tracking to determine the abundances and stoichiometries of freely-diffusing protein complexes in living cells: Past applications and future prospects. J Chem Phys 2023; 159:071002. [PMID: 37589409 PMCID: PMC10908566 DOI: 10.1063/5.0155638] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2023] [Accepted: 07/06/2023] [Indexed: 08/18/2023] Open
Abstract
Most biological processes in living cells rely on interactions between proteins. Live-cell compatible approaches that can quantify to what extent a given protein participates in homo- and hetero-oligomeric complexes of different size and subunit composition are therefore critical to advance our understanding of how cellular physiology is governed by these molecular interactions. Biomolecular complex formation changes the diffusion coefficient of constituent proteins, and these changes can be measured using fluorescence microscopy-based approaches, such as single-molecule tracking, fluorescence correlation spectroscopy, and fluorescence recovery after photobleaching. In this review, we focus on the use of single-molecule tracking to identify, resolve, and quantify the presence of freely-diffusing proteins and protein complexes in living cells. We compare and contrast different data analysis methods that are currently employed in the field and discuss experimental designs that can aid the interpretation of the obtained results. Comparisons of diffusion rates for different proteins and protein complexes in intracellular aqueous environments reported in the recent literature reveal a clear and systematic deviation from the Stokes-Einstein diffusion theory. While a complete and quantitative theoretical explanation of why such deviations manifest is missing, the available data suggest the possibility of weighing freely-diffusing proteins and protein complexes in living cells by measuring their diffusion coefficients. Mapping individual diffusive states to protein complexes of defined molecular weight, subunit stoichiometry, and structure promises to provide key new insights into how protein-protein interactions regulate protein conformational, translational, and rotational dynamics, and ultimately protein function.
Collapse
Affiliation(s)
- Joshua Robert Prindle
- Department of Chemistry, University of Virginia, Charlottesville, Virginia 22904, USA
| | - Olivia Isabella Christiane de Cuba
- Department of Molecular Physiology and Biological Physics, University of Virginia School of Medicine, Charlottesville, Virginia 22903, USA
| | | |
Collapse
|
44
|
Russell B, Rogers A, Yoder R, Kurilich M, Krishnamurthi VR, Chen J, Wang Y. Silver Ions Inhibit Bacterial Movement and Stall Flagellar Motor. Int J Mol Sci 2023; 24:11704. [PMID: 37511461 PMCID: PMC10381017 DOI: 10.3390/ijms241411704] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2023] [Revised: 07/13/2023] [Accepted: 07/18/2023] [Indexed: 07/30/2023] Open
Abstract
Silver (Ag) in different forms has been gaining broad attention due to its antimicrobial activities and the increasing resistance of bacteria to commonly prescribed antibiotics. However, various aspects of the antimicrobial mechanism of Ag have not been understood, including how Ag affects bacterial motility, a factor intimately related to bacterial virulence. Here, we report our study on how Ag+ ions affect the motility of E. coli bacteria using swimming, tethering, and rotation assays. We observed that the bacteria slowed down dramatically by >70% when subjected to Ag+ ions, providing direct evidence that Ag+ ions inhibit the motility of bacteria. In addition, through tethering and rotation assays, we monitored the rotation of flagellar motors and observed that the tumbling/pausing frequency of bacteria increased significantly by 77% in the presence of Ag+ ions. Furthermore, we analyzed the results from the tethering assay using the hidden Markov model (HMM) and found that Ag+ ions decreased bacterial tumbling/pausing-to-running transition rate significantly by 75%. The results suggest that the rotation of bacterial flagellar motors was stalled by Ag+ ions. This work provided a new quantitative understanding of the mechanism of Ag-based antimicrobial agents in bacterial motility.
Collapse
Affiliation(s)
- Benjamin Russell
- Department of Physics, University of Arkansas, Fayetteville, AR 72701, USA
| | - Ariel Rogers
- Department of Physics, University of Arkansas, Fayetteville, AR 72701, USA
| | - Ryan Yoder
- Department of Physics, University of Arkansas, Fayetteville, AR 72701, USA
| | - Matthew Kurilich
- Department of Physics, University of Arkansas, Fayetteville, AR 72701, USA
| | | | - Jingyi Chen
- Department of Chemistry and Biochemistry, University of Arkansas, Fayetteville, AR 72701, USA
- Materials Science and Engineering Program, University of Arkansas, Fayetteville, AR 72701, USA
| | - Yong Wang
- Department of Physics, University of Arkansas, Fayetteville, AR 72701, USA
- Materials Science and Engineering Program, University of Arkansas, Fayetteville, AR 72701, USA
- Cell and Molecular Biology Program, University of Arkansas, Fayetteville, AR 72701, USA
| |
Collapse
|
45
|
Loya-Lopez SI, Allen HN, Duran P, Calderon-Rivera A, Gomez K, Kumar U, Shields R, Zeng R, Dwivedi A, Saurabh S, Korczeniewska OA, Khanna R. Intranasal CRMP2-Ubc9 Inhibitor Regulates Na V 1.7 to Alleviate Trigeminal Neuropathic Pain. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.07.16.549195. [PMID: 37502910 PMCID: PMC10370107 DOI: 10.1101/2023.07.16.549195] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/29/2023]
Abstract
Dysregulation of voltage-gated sodium Na V 1.7 channels in sensory neurons contributes to chronic pain conditions, including trigeminal neuropathic pain. We previously reported that chronic pain results in part from increased SUMOylation of collapsin response mediator protein 2 (CRMP2), leading to an increased CRMP2/Na V 1.7 interaction and increased functional activity of Na V 1.7. Targeting this feed-forward regulation, we developed compound 194 , which inhibits CRMP2 SUMOylation mediated by the SUMO-conjugating enzyme Ubc9. We further demonstrated that 194 effectively reduces the functional activity of Na V 1.7 channels in dorsal root ganglia neurons and alleviated inflammatory and neuropathic pain. Here, we employed a comprehensive array of investigative approaches, encompassing biochemical, pharmacological, genetic, electrophysiological, and behavioral analyses, to assess the functional implications of Na V 1.7 regulation by CRMP2 in trigeminal ganglia (TG) neurons. We confirmed the expression of Scn9a , Dpysl2 , and UBE2I within TG neurons. Furthermore, we found an interaction between CRMP2 and Na V 1.7, with CRMP2 being SUMOylated in these sensory ganglia. Disrupting CRMP2 SUMOylation with compound 194 uncoupled the CRMP2/Na V 1.7 interaction, impeded Na V 1.7 diffusion on the plasma membrane, and subsequently diminished Na V 1.7 activity. Compound 194 also led to a reduction in TG neuron excitability. Finally, when intranasally administered to rats with chronic constriction injury of the infraorbital nerve (CCI-ION), 194 significantly decreased nociceptive behaviors. Collectively, our findings underscore the critical role of CRMP2 in regulating Na V 1.7 within TG neurons, emphasizing the importance of this indirect modulation in trigeminal neuropathic pain.
Collapse
|
46
|
Henning P, Köster T, Haack F, Burrage K, Uhrmacher AM. Implications of different membrane compartmentalization models in particle-based in silico studies. ROYAL SOCIETY OPEN SCIENCE 2023; 10:221177. [PMID: 37416823 PMCID: PMC10320350 DOI: 10.1098/rsos.221177] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/08/2022] [Accepted: 06/12/2023] [Indexed: 07/08/2023]
Abstract
Studying membrane dynamics is important to understand the cellular response to environmental stimuli. A decisive spatial characteristic of the plasma membrane is its compartmental structure created by the actin-based membrane-skeleton (fences) and anchored transmembrane proteins (pickets). Particle-based reaction-diffusion simulation of the membrane offers a suitable temporal and spatial resolution to analyse its spatially heterogeneous and stochastic dynamics. Fences have been modelled via hop probabilities, potentials or explicit picket fences. Our study analyses the different approaches' constraints and their impact on simulation results and performance. Each of the methods comes with its own constraints; the picket fences require small timesteps, potential fences might induce a bias in diffusion in crowded systems, and probabilistic fences, in addition to carefully scaling the probability with the timesteps, induce higher computational costs for each propagation step.
Collapse
Affiliation(s)
- Philipp Henning
- Institute for Visual and Analytic Computing, University of Rostock, Rostock, Germany
| | - Till Köster
- Institute for Visual and Analytic Computing, University of Rostock, Rostock, Germany
| | - Fiete Haack
- Institute for Visual and Analytic Computing, University of Rostock, Rostock, Germany
| | - Kevin Burrage
- School of Mathematical Sciences, Queensland University of Technology, Brisbane, Australia
- Visiting Professor, Department of Computer Science, University of Oxford, Oxford, UK
| | - Adelinde M. Uhrmacher
- Institute for Visual and Analytic Computing, University of Rostock, Rostock, Germany
| |
Collapse
|
47
|
Nguyen TD, Chen YI, Chen LH, Yeh HC. Recent Advances in Single-Molecule Tracking and Imaging Techniques. ANNUAL REVIEW OF ANALYTICAL CHEMISTRY (PALO ALTO, CALIF.) 2023; 16:253-284. [PMID: 37314878 DOI: 10.1146/annurev-anchem-091922-073057] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
Since the early 1990s, single-molecule detection in solution at room temperature has enabled direct observation of single biomolecules at work in real time and under physiological conditions, providing insights into complex biological systems that the traditional ensemble methods cannot offer. In particular, recent advances in single-molecule tracking techniques allow researchers to follow individual biomolecules in their native environments for a timescale of seconds to minutes, revealing not only the distinct pathways these biomolecules take for downstream signaling but also their roles in supporting life. In this review, we discuss various single-molecule tracking and imaging techniques developed to date, with an emphasis on advanced three-dimensional (3D) tracking systems that not only achieve ultrahigh spatiotemporal resolution but also provide sufficient working depths suitable for tracking single molecules in 3D tissue models. We then summarize the observables that can be extracted from the trajectory data. Methods to perform single-molecule clustering analysis and future directions are also discussed.
Collapse
Affiliation(s)
- Trung Duc Nguyen
- Department of Biomedical Engineering, University of Texas at Austin, Austin, Texas, USA;
| | - Yuan-I Chen
- Department of Biomedical Engineering, University of Texas at Austin, Austin, Texas, USA;
| | - Limin H Chen
- Department of Biomedical Engineering, University of Texas at Austin, Austin, Texas, USA;
| | - Hsin-Chih Yeh
- Department of Biomedical Engineering, University of Texas at Austin, Austin, Texas, USA;
- Texas Materials Institute, University of Texas at Austin, Austin, Texas, USA
| |
Collapse
|
48
|
Fan D, Bajgiran SR, Samghabadi FS, Dutta C, Gillett E, Rossky PJ, Conrad JC, Marciel AB, Landes CF. Imaging Heterogeneous 3D Dynamics of Individual Solutes in a Polyelectrolyte Brush. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2023. [PMID: 37290000 DOI: 10.1021/acs.langmuir.3c00868] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Understanding molecular transport in polyelectrolyte brushes (PEBs) is crucial for applications such as separations, drug delivery, anti-fouling, and biosensors, where structural features of the polymer control intermolecular interactions. The complex structure and local heterogeneity of PEBs, while theoretically predicted, are not easily accessed with conventional experimental methods. In this work, we use 3D single-molecule tracking to understand transport behavior within a cationic poly(2-(N,N-dimethylamino)ethyl acrylate) (PDMAEA) brush using an anionic dye, Alexa Fluor 546, as the probe. The analysis is done by a parallelized, unbiased 3D tracking algorithm. Our results explicitly demonstrate that spatial heterogeneity within the brush manifests as heterogeneity of single-molecule displacements. Two distinct populations of probe motion are identified, with anticorrelated axial and lateral transport confinement, which we believe to correspond to intra- vs inter-chain probe motion.
Collapse
Affiliation(s)
- Dongyu Fan
- Department of Chemical and Biomolecular Engineering, Rice University, Houston, Texas 77005, United States
| | - Shahryar Ramezani Bajgiran
- Department of Chemical and Biomolecular Engineering, Rice University, Houston, Texas 77005, United States
| | - Farshad Safi Samghabadi
- Department of Chemical and Biomolecular Engineering, University of Houston, Houston, Texas 77204, United States
| | - Chayan Dutta
- Department of Chemistry, Georgia State University, Atlanta, Georgia 30302, United States
| | - Emil Gillett
- Department of Chemistry, Rice University, Houston, Texas 77005, United States
| | - Peter J Rossky
- Department of Chemical and Biomolecular Engineering, Rice University, Houston, Texas 77005, United States
- Department of Chemistry, Rice University, Houston, Texas 77005, United States
- Smalley Curl Institute, Rice University, Houston, Texas 77005, United States
| | - Jacinta C Conrad
- Department of Chemical and Biomolecular Engineering, University of Houston, Houston, Texas 77204, United States
| | - Amanda B Marciel
- Department of Chemical and Biomolecular Engineering, Rice University, Houston, Texas 77005, United States
| | - Christy F Landes
- Department of Chemical and Biomolecular Engineering, Rice University, Houston, Texas 77005, United States
- Department of Chemistry, Rice University, Houston, Texas 77005, United States
- Department of Electrical and Computer Engineering, Rice University, Houston, Texas 77005, United States
- Smalley Curl Institute, Rice University, Houston, Texas 77005, United States
| |
Collapse
|
49
|
Hu Y, Becker ML, Willits RK. Quantification of cell migration: metrics selection to model application. Front Cell Dev Biol 2023; 11:1155882. [PMID: 37255596 PMCID: PMC10225508 DOI: 10.3389/fcell.2023.1155882] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2023] [Accepted: 05/05/2023] [Indexed: 06/01/2023] Open
Abstract
Cell migration plays an essential role in physiological and pathological states, such as immune response, tissue generation and tumor development. This phenomenon can occur spontaneously or it can be triggered by an external stimuli, including biochemical, mechanical, or electrical cues that induce or direct cells to migrate. The migratory response to these cues is foundational to several fields including neuroscience, cancer and regenerative medicine. Various platforms are available to qualitatively and quantitatively measure cell migration, making the measurements of cell motility straight-forward. Migratory behavior must be analyzed by multiple metrics and then models to connect the measurements to physiological meaning. This review will focus on describing and quantifying cell movement for individual cell migration.
Collapse
Affiliation(s)
- Yang Hu
- Department of Chemical Engineering, College of Engineering, Northeastern University, Boston, MA, United States
| | - Matthew L. Becker
- Departments of Chemistry, Mechanical Engineering and Materials Science, Biomedical Engineering and Orthopedic Surgery, Duke University, Durham, NC, United States
| | - Rebecca Kuntz Willits
- Department of Chemical Engineering, College of Engineering, Northeastern University, Boston, MA, United States
- Department of Bioengineering, College of Engineering, Northeastern University, Boston, MA, United States
| |
Collapse
|
50
|
Simon F, Tinevez JY, van Teeffelen S. ExTrack characterizes transition kinetics and diffusion in noisy single-particle tracks. J Cell Biol 2023; 222:e202208059. [PMID: 36880553 PMCID: PMC9997658 DOI: 10.1083/jcb.202208059] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2022] [Revised: 12/01/2022] [Accepted: 01/27/2023] [Indexed: 03/08/2023] Open
Abstract
Single-particle tracking microscopy is a powerful technique to investigate how proteins dynamically interact with their environment in live cells. However, the analysis of tracks is confounded by noisy molecule localization, short tracks, and rapid transitions between different motion states, notably between immobile and diffusive states. Here, we propose a probabilistic method termed ExTrack that uses the full spatio-temporal information of tracks to extract global model parameters, to calculate state probabilities at every time point, to reveal distributions of state durations, and to refine the positions of bound molecules. ExTrack works for a wide range of diffusion coefficients and transition rates, even if experimental data deviate from model assumptions. We demonstrate its capacity by applying it to slowly diffusing and rapidly transitioning bacterial envelope proteins. ExTrack greatly increases the regime of computationally analyzable noisy single-particle tracks. The ExTrack package is available in ImageJ and Python.
Collapse
Affiliation(s)
- François Simon
- Département de Microbiologie, Infectiologie, et Immunologie, Faculté de Médecine, Université de Montréal, Montréal, Quebec, Canada
- Microbial Morphogenesis and Growth Lab, Institut Pasteur, Université de Paris Cité, Paris, France
| | - Jean-Yves Tinevez
- Image Analysis Hub, Institut Pasteur, Université de Paris Cité, Paris, France
| | - Sven van Teeffelen
- Département de Microbiologie, Infectiologie, et Immunologie, Faculté de Médecine, Université de Montréal, Montréal, Quebec, Canada
- Microbial Morphogenesis and Growth Lab, Institut Pasteur, Université de Paris Cité, Paris, France
| |
Collapse
|