Biomaterial Database

Partial purification and characterization of the intercellular bridge from cultured mouse cells. 1978

G Krystal, and J B Rattner, and B A Hamkalo

At the completion of mitosis, the two daughter cells are connected by a channel of membrane-bound cytoplasm, the intercellular bridge. This structure contains parallel arrays of spindle microtubules which are associated, at the bridge midline, with a metallophilic band called the midbody. In an effort to characterize midbody components, intercellular bridges were partially purified. The purification consisted of brief sonication of telophase populations of mouse L929 cells in order to shear intercellular bridges from daughter cells, digestion of chromatin by an excess of micrococcal nuclease, and differential centrifugation to enrich for intercellular bridges. Electron microscopy of these preparations substantiated the identity of the bulk of material as intercellular bridges. After solubilization with sodium dodecyl sulfate, the protein components of these preparations were iodinated with Na(125)I and separated by two-dimensional gel electrophoresis. From these analyses, the major polypeptide components of intercellular bridges appear to be tubulin, varying amounts of plasma membrane proteins, and a polypeptide with an apparent molecular weight of 42,000. Time-course studies reveal that this polypeptide is first detectable in a pelletable form approximately 30 min after cells are released from metaphase block, reaches maximal spot intensity in late telophase, and is no longer detectable in G1 populations. We interpret these data to suggest that the 42,000-dalton polypeptide is a component of the midbody.

UI	MeSH Term	Description	Entries
D007365	Intercellular Junctions	Direct contact of a cell with a neighboring cell. Most such junctions are too small to be resolved by light microscopy, but they can be visualized by conventional or freeze-fracture electron microscopy, both of which show that the interacting CELL MEMBRANE and often the underlying CYTOPLASM and the intervening EXTRACELLULAR SPACE are highly specialized in these regions. (From Alberts et al., Molecular Biology of the Cell, 2d ed, p792)	Cell Junctions,Cell Junction,Intercellular Junction,Junction, Cell,Junction, Intercellular,Junctions, Cell,Junctions, Intercellular
D008565	Membrane Proteins	Proteins which are found in membranes including cellular and intracellular membranes. They consist of two types, peripheral and integral proteins. They include most membrane-associated enzymes, antigenic proteins, transport proteins, and drug, hormone, and lectin receptors.	Cell Membrane Protein,Cell Membrane Proteins,Cell Surface Protein,Cell Surface Proteins,Integral Membrane Proteins,Membrane-Associated Protein,Surface Protein,Surface Proteins,Integral Membrane Protein,Membrane Protein,Membrane-Associated Proteins,Membrane Associated Protein,Membrane Associated Proteins,Membrane Protein, Cell,Membrane Protein, Integral,Membrane Proteins, Integral,Protein, Cell Membrane,Protein, Cell Surface,Protein, Integral Membrane,Protein, Membrane,Protein, Membrane-Associated,Protein, Surface,Proteins, Cell Membrane,Proteins, Cell Surface,Proteins, Integral Membrane,Proteins, Membrane,Proteins, Membrane-Associated,Proteins, Surface,Surface Protein, Cell
D010455	Peptides	Members of the class of compounds composed of AMINO ACIDS joined together by peptide bonds between adjacent amino acids into linear, branched or cyclical structures. OLIGOPEPTIDES are composed of approximately 2-12 amino acids. Polypeptides are composed of approximately 13 or more amino acids. PROTEINS are considered to be larger versions of peptides that can form into complex structures such as ENZYMES and RECEPTORS.	Peptide,Polypeptide,Polypeptides
D002478	Cells, Cultured	Cells propagated in vitro in special media conducive to their growth. Cultured cells are used to study developmental, morphologic, metabolic, physiologic, and genetic processes, among others.	Cultured Cells,Cell, Cultured,Cultured Cell
D004586	Electrophoresis	An electrochemical process in which macromolecules or colloidal particles with a net electric charge migrate in a solution under the influence of an electric current.	Electrophoreses
D014404	Tubulin	A microtubule subunit protein found in large quantities in mammalian brain. It has also been isolated from SPERM FLAGELLUM; CILIA; and other sources. Structurally, the protein is a dimer with a molecular weight of approximately 120,000 and a sedimentation coefficient of 5.8S. It binds to COLCHICINE; VINCRISTINE; and VINBLASTINE.	alpha-Tubulin,beta-Tubulin,delta-Tubulin,epsilon-Tubulin,gamma-Tubulin,alpha Tubulin,beta Tubulin,delta Tubulin,epsilon Tubulin,gamma Tubulin