Biomaterial Database

In vitro fusion of endocytic vesicles is inhibited by cyclin A-cdc2 kinase. 1993

P G Woodman, and J P Adamczewski, and T Hunt, and G Warren

Department of Biochemistry and Molecular Biology, University of Manchester Medical School, United Kingdom.

Receptor-mediated endocytosis and recycling are inhibited in mitotic mammalian cells, and previous studies have shown that inhibition of endocytic vesicle fusion in vitro occurs via cyclin B-cdc2 kinase. To test for the ability of cyclin A-cdc2 kinase to inhibit endocytic vesicle fusion, we employed recombinant cyclin A proteins. Addition of cyclin A to interphase extracts activated a histone kinase and markedly reduced the efficiency of endocytic vesicle fusion. By a number of criteria, inhibition of fusion was shown to be due to the action of cyclin A, via the mitosis-specific cdc2 kinase, and not an indirect effect through cyclin B. Two-stage incubations were used to demonstrate that at least one target of cyclin A-cdc2 kinase is a cytosolic component of the fusion apparatus. Reconstitution experiments showed that this component was also modified in mitotic cytosols and was unaffected by N-ethyl maleimide treatment.

UI	MeSH Term	Description	Entries
D002460	Cell Line	Established cell cultures that have the potential to propagate indefinitely.	Cell Lines,Line, Cell,Lines, Cell
D003600	Cytosol	Intracellular fluid from the cytoplasm after removal of ORGANELLES and other insoluble cytoplasmic components.	Cytosols
D004705	Endocytosis	Cellular uptake of extracellular materials within membrane-limited vacuoles or microvesicles. ENDOSOMES play a central role in endocytosis.	Endocytoses
D006367	HeLa Cells	The first continuously cultured human malignant CELL LINE, derived from the cervical carcinoma of Henrietta Lacks. These cells are used for, among other things, VIRUS CULTIVATION and PRECLINICAL DRUG EVALUATION assays.	Cell, HeLa,Cells, HeLa,HeLa Cell
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D015388	Organelles	Specific particles of membrane-bound organized living substances present in eukaryotic cells, such as the MITOCHONDRIA; the GOLGI APPARATUS; ENDOPLASMIC RETICULUM; LYSOSOMES; PLASTIDS; and VACUOLES.	Organelle
D016203	CDC2 Protein Kinase	Phosphoprotein with protein kinase activity that functions in the G2/M phase transition of the CELL CYCLE. It is the catalytic subunit of the MATURATION-PROMOTING FACTOR and complexes with both CYCLIN A and CYCLIN B in mammalian cells. The maximal activity of cyclin-dependent kinase 1 is achieved when it is fully dephosphorylated.	Cdk1 Protein Kinase,Cyclin-Dependent Kinase 1,Histone Kinase p34(cdc2),Protein p34cdc2,p34cdc2 Protein,cdc2+ Protein,cdk1 Kinase,Cyclin Dependent Kinase 1,Protein Kinase, CDC2,Protein Kinase, Cdk1,p34cdc2, Protein
D016213	Cyclins	A large family of regulatory proteins that function as accessory subunits to a variety of CYCLIN-DEPENDENT KINASES. They generally function as ENZYME ACTIVATORS that drive the CELL CYCLE through transitions between phases. A subset of cyclins may also function as transcriptional regulators.	Cyclin