0000000000165255
AUTHOR
Sami F. Willman
Protein diffusion in mammalian cell cytoplasm.
We introduce a new method for mesoscopic modeling of protein diffusion in an entire cell. This method is based on the construction of a three-dimensional digital model cell from confocal microscopy data. The model cell is segmented into the cytoplasm, nucleus, plasma membrane, and nuclear envelope, in which environment protein motion is modeled by fully numerical mesoscopic methods. Finer cellular structures that cannot be resolved with the imaging technique, which significantly affect protein motion, are accounted for in this method by assigning an effective, position-dependent porosity to the cell. This porosity can also be determined by confocal microscopy using the equilibrium distribut…
Reactive Self-Assembly and Specific Cellular Delivery of NCO-sP(EO-stat-PO)-Derived Nanogels
This study presents the reactive self-assembly of isocyanate functional and amphiphilic six-arm, star-shaped polyether prepolymers in water into nanogels. Intrinsic molecular amphiphilicity, mainly driven by the isophorone moiety at the distal endings of the star-shaped molecules, allows for the preparation of spherical particles with an adjustable size of 100-200 nm by self-assembly and subsequent covalent cross-linking without the need for organic solvents or surfactants. Covalent attachment of a fluorescence dye and either the cell-penetrating TAT peptide or a random control peptide sequence shows that only TAT-labeled nanogels are internalized by HeLa cells. The nanogels thus specifical…
Distribution and Dynamics of Transcription-Associated Proteins during Parvovirus Infection
ABSTRACT Canine parvovirus (CPV) infection leads to reorganization of nuclear proteinaceous subcompartments. Our studies showed that virus infection causes a time-dependent increase in the amount of viral nonstructural protein NS1 mRNA. Fluorescence recovery after photobleaching showed that the recovery kinetics of nuclear transcription-associated proteins, TATA binding protein (TBP), transcription factor IIB (TFIIB), and poly(A) binding protein nuclear 1 (PABPN1) were different in infected and noninfected cells, pointing to virus-induced alterations in binding dynamics of these proteins.