Posts Tagged ‘separated’

ExoMars lander on track for a Wednesday touchdown

The ExoMars 2016’s Schiaparelli lander successfully separated from its mothership on Sunday morning, and is currently en route to the surface of the Red Planet as it looks to become the first European Space Agency (ESA) probe to make contact with Mars in nearly 15 years. According to BBC News, the lander separated from the […]

The post ExoMars lander on track for a Wednesday touchdown appeared first on Redorbit.

Did Einstein predict Quantum Entanglement in 1905?

Quantum entanglement is defined "as a physical phenomenon that occurs when pairs or groups of particles are generated or interact in ways such that the quantum state of each particle cannot be described independently instead, a quantum state may be given for the system as a whole. Einstein referred to this as "spooky action at […]

What’s inside dwarf planet Ceres? New study has the answer

While photos cannot reveal the interior of the dwarf planet Ceres, scientists have used data on its gravitational effects to determine what the insides of the celestial body might look like. Ceres is the largest object in our Solar System’s asteroid belt and NASA’s Dawn probe entered into orbit around the protoplanet in April of […]

The post What’s inside dwarf planet Ceres? New study has the answer appeared first on Redorbit.

Ki-67 acts as a biological surfactant to disperse mitotic chromosomes

Eukaryotic genomes are partitioned into chromosomes that form compact and spatially well-separated mechanical bodies during mitosis. This enables chromosomes to move independently of each other for segregation of precisely one copy of the genome to each of the nascent daughter cells. Despite insights into the spatial organization of mitotic chromosomes and the discovery of proteins at the chromosome surface, the molecular and biophysical bases of mitotic chromosome structural individuality have remained unclear. Here we report that the proliferation marker protein Ki-67 (encoded by the MKI67 gene), a component of the mitotic chromosome periphery, prevents chromosomes from collapsing into a single chromatin mass after nuclear envelope disassembly, thus enabling independent chromosome motility and efficient interactions with the mitotic spindle. The chromosome separation function of human Ki-67 is not confined within a specific protein domain, but correlates with size and net charge of truncation mutants that apparently lack secondary structure. This suggests that Ki-67 forms a steric and electrostatic charge barrier, similar to surface-active agents (surfactants) that disperse particles or phase-separated liquid droplets in solvents. Fluorescence correlation spectroscopy showed a high surface density of Ki-67 and dual-colour labelling of both protein termini revealed an extended molecular conformation, indicating brush-like arrangements that are characteristic of polymeric surfactants. Our study thus elucidates a biomechanical role of the mitotic chromosome periphery in mammalian cells and suggests that natural proteins can function as surfactants in intracellular compartmentalization.

Powered by WordPress | Designed by: video game | Thanks to search engine optimization, seo agency and Privater Sicherheitsdienst