Biomaterial Database

Compartments of tubulin and tubulin-like proteins in differentiating neubroblastoma cells. 1979

K Y Chan, and C F Baxter

Cytoplasmic, tubular and particulate fractions of differentiating neuroblastoma cells were prepared and the tubulin together with tubulin-like proteins was measured in each cell fraction during different stages of cell differentiation. In undifferentiated cells, 73%, 5% and 22% of the tubulin and tubulin-like proteins were contained in the cytoplasmic, tubular and particulate fractions, respectively. After 5 days of differentiation, the overall content of tubulin and tubulin-like proteins had increased by 73%. This corresponded to increases of 45%, 145% and 100% in the cytoplasmic, microtubular and particulate fractions, respectively. The increase in membrane-bound (particulate) tubulin and tubulin-like proteins was significantly greater than the total increase of proteins in the particulate fraction. Polyacrylamide gel electrophoresis of the proteins in each subcellular fraction revealed the presence of protein bands corresponding to the alpha and beta subunits of tubulin. Whereas these bands indicated equal amounts of protein in the alpha and beta positions for the tubular and particulate cell fractions, an analysis of the cytoplasmic fraction revealed much more protein migrating to the alpha-tubulin position than to the beta-tubulin position, especially during cell differentiation. Furthermore, two overlapping but distinct protein bands were demonstrable in the position of the alpha-tubulin from the cytoplasmic fraction. These bands were designated alpha 1 and alpha 2. The particulate fraction contained only the alpha 1 and the tubular fraction only the alpha 2 protein band. The addition of 1 mM dibutyryl cyclic AMP to the neuroblastoma cells, at the time when the serum was withdrawn, enhanced the rate of differentiation and the redistribution of tubulin and tubulin-like proteins within the 3 cellular compartments. These results are discussed as they relate to the regulation, biosynthesis, turnover and compartmentation of tubulin and tubulin-like proteins in differentiating neuroblastoma cells.

UI	MeSH Term	Description	Entries
D007700	Kinetics	The rate dynamics in chemical or physical systems.
D008870	Microtubules	Slender, cylindrical filaments found in the cytoskeleton of plant and animal cells. They are composed of the protein TUBULIN and are influenced by TUBULIN MODULATORS.	Microtubule
D009419	Nerve Tissue Proteins		Proteins, Nerve Tissue,Tissue Proteins, Nerve
D009447	Neuroblastoma	A common neoplasm of early childhood arising from neural crest cells in the sympathetic nervous system, and characterized by diverse clinical behavior, ranging from spontaneous remission to rapid metastatic progression and death. This tumor is the most common intraabdominal malignancy of childhood, but it may also arise from thorax, neck, or rarely occur in the central nervous system. Histologic features include uniform round cells with hyperchromatic nuclei arranged in nests and separated by fibrovascular septa. Neuroblastomas may be associated with the opsoclonus-myoclonus syndrome. (From DeVita et al., Cancer: Principles and Practice of Oncology, 5th ed, pp2099-2101; Curr Opin Oncol 1998 Jan;10(1):43-51)	Neuroblastomas
D002454	Cell Differentiation	Progressive restriction of the developmental potential and increasing specialization of function that leads to the formation of specialized cells, tissues, and organs.	Differentiation, Cell,Cell Differentiations,Differentiations, Cell
D002460	Cell Line	Established cell cultures that have the potential to propagate indefinitely.	Cell Lines,Line, Cell,Lines, Cell
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D013347	Subcellular Fractions	Components of a cell produced by various separation techniques which, though they disrupt the delicate anatomy of a cell, preserve the structure and physiology of its functioning constituents for biochemical and ultrastructural analysis. (From Alberts et al., Molecular Biology of the Cell, 2d ed, p163)	Fraction, Subcellular,Fractions, Subcellular,Subcellular Fraction
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
D046911	Macromolecular Substances	Compounds and molecular complexes that consist of very large numbers of atoms and are generally over 500 kDa in size. In biological systems macromolecular substances usually can be visualized using ELECTRON MICROSCOPY and are distinguished from ORGANELLES by the lack of a membrane structure.	Macromolecular Complexes,Macromolecular Compounds,Macromolecular Compounds and Complexes,Complexes, Macromolecular,Compounds, Macromolecular,Substances, Macromolecular