scholarly journals Single mRNP analysis by super-resolution microscopy and fluorescence correlation spectroscopy reveals that small mRNP granules represent mRNA singletons

2019 ◽  
Author(s):  
Àngels Mateu-Regué ◽  
Jan Christiansen ◽  
Frederik Otzen Bagger ◽  
Christian Hellriegel ◽  
Finn Cilius Nielsen
Keyword(s):  
Translational Control ◽  
Fluorescence Correlation Spectroscopy ◽  
Rna Binding ◽  
Rna Binding Proteins ◽  
Super Resolution ◽  
Correlation Spectroscopy ◽  
Live Cells ◽  
Nuclear Pore ◽  
Fluorescence Correlation ◽  
Super Resolution Microscopy

SummarySmall cytoplasmic mRNP granules are implicated in mRNA transport, translational control and decay. Employing Super-resolution Microscopy and Fluorescence Correlation Spectroscopy, we analyzed the molecular composition and dynamics of single cytoplasmic YBX1_IMP1 mRNP granules in live cells. Granules appeared elongated and branched with patches of IMP1 and YBX1 distributed along mRNA, reflecting the attachment of the two RNA-binding proteins in cis. Particles form at the nuclear pore and are spatially segregated from translating ribosomes, so the mRNP is a repository for mRNAs awaiting translation. In agreement with the average number of mRNA-binding sites derived from CLIP analyses, individual mRNPs contain 5 to 15 molecules of YBX1 and IMP1 and a single poly(A) tail identified by PABPC1. Taken together, we conclude that small cytoplasmic mRNP granules are mRNA singletons, thus depicting the cellular transcriptome. Consequently, expression of functionally related mRNAs in RNA regulons is unlikely to result from coordinated assembly.

scholarly journals Fluorescence Correlation and Cross-Correlation Spectroscopy Unveil Cytoplasmic mRNP Composition and Dynamics

2020 ◽  
Author(s):  
Àngels Mateu-Regué ◽  
Jan Christiansen ◽  
Christian Hellriegel ◽  
Finn Cilius Nielsen
Keyword(s):  
Life Cycle ◽  
Dynamic Analysis ◽  
Cross Correlation ◽  
Rna Binding ◽  
Rna Binding Proteins ◽  
Correlation Spectroscopy ◽  
Live Cells ◽  
Macromolecular Complexes ◽  
Fluorescence Correlation ◽  
Macromolecular Composition

ABSTRACTUnderstanding the mRNA life cycle requires analysis of the dynamic macromolecular composition and stoichiometry of mRNPs. Fluorescence correlation and cross-correlation spectroscopy (FCS and FCCS) are appealing technologies to study mRNP complexes because they readily provide information about the molecular composition, stoichiometry, heterogeneity and dynamics of the particles. We developed FCS protocols for analysis of live cells and cellular lysates, and demonstrate the feasibility of analysing common cytoplasmic mRNPs composed of core factor YBX1, IMPs (or IGF2BPs) and their interactions with other RNA binding proteins such as PABPC1, ELAVL2 (HuB), STAU1 and FMRP. FCCS corroborated previously reported RNA dependent interactions between the factors and provided an estimate of the relative overlap between the factors in the mRNPs. In this way FCS and FCCS provide a new and useful approach for the quantitative and dynamic analysis of mRNP macromolecular complexes that may complement current biochemical approaches.

scholarly journals Characterization of Porous Materials by Fluorescence Correlation Spectroscopy Super-resolution Optical Fluctuation Imaging

ACS Nano ◽  
2015 ◽  
Vol 9 (9) ◽  
pp. 9158-9166 ◽  
Author(s):  
Lydia Kisley ◽  
Rachel Brunetti ◽  
Lawrence J. Tauzin ◽  
Bo Shuang ◽  
Xiyu Yi ◽  
...  
Keyword(s):  
Porous Materials ◽  
Fluorescence Correlation Spectroscopy ◽  
Super Resolution ◽  
Correlation Spectroscopy ◽  
Fluorescence Correlation

scholarly journals Physicochemical Properties of Chromosomes in Live Cells Characterized by Label-Free Imaging and Fluorescence Correlation Spectroscopy

2019 ◽  
Author(s):  
Tae-Keun Kim ◽  
Byong-Wook Lee ◽  
Fumihiko Fujii ◽  
Kee-Hang Lee ◽  
YongKeun Park ◽  
...  
Keyword(s):  
Physicochemical Properties ◽  
Fluorescence Correlation Spectroscopy ◽  
Three Dimensional ◽  
Correlation Spectroscopy ◽  
Laser Scanning Microscopy ◽  
Optical Diffraction ◽  
Live Cells ◽  
Label Free ◽  
Mitotic Chromosomes ◽  
Fluorescence Correlation

AbstractThe cell nucleus is a three-dimensional, dynamic organelle that is organized into many subnuclear bodies, such as chromatin and nucleoli. The structure and function of these bodies is maintained by diffusion and interactions between related factors as well as dynamic and structural changes. Recent studies using fluorescent microscopic techniques suggest that protein factors can access and are freely mobile in mitotic chromosomes, despite their densely packed structure. However, the physicochemical properties of the chromosome itself during cell division are not yet fully understood. Physical parameters, such as the refractive index (RI), volume of the mitotic chromosome, and diffusion coefficients of fluorescent probes inside the chromosome were quantified using an approach combining label-free optical diffraction tomography with complementary confocal laser scanning microscopy and fluorescence correlation spectroscopy. Variance in these parameters correlated among various osmotic conditions, suggesting that changes in RI are consistent with those in the diffusion coefficient for mitotic chromosomes and cytosol. Serial RI tomography images of chromosomes in live cells during mitosis were compared with three-dimensional confocal micrographs to demonstrate that compaction and decompaction of chromosomes induced by osmotic change were characterized by linked changes in chromosome RI, volume, and the mobility of fluorescent proteins.

Sign in / Sign up

Export Citation Format

Share Document