Golgi membrane

The mechanism of inhibition has not been characterized, but it is probably related to the ionophoretic properties of these antibiotics. Monensin has been shown to inhibit the intracellular transport of viral membrane proteins of cells infected with Semliki Forest vims (169). The formation of syncytia, normally observed when T-lymphoblastoid cell line (CEM) cells are cocultivated with human immunodeficiency vims (HlV-l)-infected T-ceU leukemia cell line (MOLT-3) cells, was significantly inhibited in the presence of monensin (170). This observation suggests that the viral glycoproteins in the treated cells were not transported to the cell surface from the Golgi membrane. 

A pre-requisite for clathrin-coat assembly is the recruitment to the membrane of an adaptor complex. Similar to what has been observed for the recruitment of coatomer to Golgi membranes, adaptor binding is dependent on the presence of ARF-GTP. However, in contrast to COPI vesicle formation, ARF-GTP is suggested to act in a process before budding and not as a stoichiometric coat component. Other differences between COP-coated and clathrin-coated vesicles concern their uncoating mechanism. Disassembly of clathrin-coated vesicles is believed to depend on the chaperoneHSC 70 and on auxilin. 

The lipid compositions of plasma membranes, endoplasmic reticulum and Golgi membranes are distinct 26 Cholesterol transport and regulation in the central nervous system is distinct from that of peripheral tissues 26 In adult brain most cholesterol synthesis occurs in astrocytes 26 The astrocytic cholesterol supply to neurons is important for neuronal development and remodeling 27 The structure and roles of membrane microdomains (rafts) in cell membranes are under intensive study but many aspects are still unresolved 28... 

The lipid compositions of plasma membranes, endoplasmic reticulum and Golgi membranes are distinct. All... 

Van Meer, G. Lipids of the Golgi membrane. Trends Cell Biol. 8 29-33,1998. 

Ali MS, Nishimura M, Mitsui T, Akazawa T. Isolation and characterization of Golgi membrane from suspension-cultured cells of sycamore (Acerpseudoplatanus L.). Plant Cell Physiol 1985 26 1119-1133. 

The vesicles used in the retrograde transport from the Golgi to the ER are coated by the COP I protein, whereas in the anterograde transport from the ER to the Golgi, the COP II protein seems to be a principal player. The dilysine motif turned out to interact with COP I, directing the retrieval to the ER. This is plausible because COP I exists on the cytosolic surface of the Golgi membrane. 

Denker SP, McCaffery JM, Palade GE, Insel PA, Farquhar MG (1996) Differential distribution of alpha subunits and beta gamma subunits of heterotrimeric G proteins on Golgi membranes of the exocrine pancreas. J Cell Biol 133 1027-1040... 

Stow JL, de Almeida JB, Narula N, Holtzman EJ, Ercolani L, Ausiello DA (1991) A heterotrimeric G protein, G alpha i-3, on Golgi membranes regulates the secretion of a heparan sulfate proteoglycan in LLC-PKl epithelial cells. J Cell Biol 114 1113-1124... 

Molecular biology ilimaquuuxie /Sigma 2000 ma-( esquit p./triggering the reversible In eakdown of Golgi membranes marine tropical Hippospongia spp. and... 

Phosphorylation occurs in the Golgi membranes of the mammary cell, catalysed by two serine-specific casein kinases. Only certain serines are phosphorylated the principal recognition site is Ser/Thr.X.Y, where Y is a glutamyl and occasionally an aspartyl residue once a serine residue has been phosphorylated, SerP can serve as a recognition site. X may be any amino acid but a basic or a very bulky residue may reduce the extent of phosphorylation. However, not all serine residues in a suitable sequence are phosphorylated, suggesting that there may be a further topological requirement, e.g. a surface location in the protein conformation. 

Protein fractions having lectin activity have been extracted from mitochondria, plasma, and Golgi membranes, and from the endoplasmic reticulum of mung-bean hypocotyls, as well as from total-membrane fractions from a variety of plant tissues.257 The carbohydrate specificity of the lectin fractions differs with the membrane type. It is conceivable that, in addition to cell-wall lectin-membrane interactions, there may also be membrane lectin-cell wall, noncovalent bonds. 

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