scholarly journals Viral membrane proteins acquire galactose in trans Golgi cisternae during intracellular transport

1982 ◽  
Vol 95 (3) ◽  
pp. 781-792 ◽  
Author(s):  
G. Griffiths
Keyword(s):  
Membrane Proteins ◽  
Intracellular Transport ◽  
Viral Membrane ◽  
In Trans

scholarly journals Dissection of the Golgi complex. I. Monensin inhibits the transport of viral membrane proteins from medial to trans Golgi cisternae in baby hamster kidney cells infected with Semliki Forest virus.

1983 ◽  
Vol 96 (3) ◽  
pp. 835-850 ◽  
Author(s):  
G Griffiths ◽  
P Quinn ◽  
G Warren
Keyword(s):  
Membrane Proteins ◽  
Intracellular Transport ◽  
Semliki Forest Virus ◽  
Ricinus Communis ◽  
Baby Hamster Kidney ◽  
Viral Membrane ◽  
Golgi Stack ◽  
Large Numbers ◽  
Block Movement ◽  
In Trans

Baby hamster kidney (BHK) cells were infected with Semliki Forest virus (SFV) and, 2 h later, were treated for 4 h with 10 microM monensin. Each of the four to six flattened cisternae in the Golgi stack became swollen and separated from the others. Intracellular transport of the viral membrane proteins was almost completely inhibited, but their synthesis continued and they accumulated in the swollen Golgi cisternae before the monensin block. In consequence, these cisternae bound large numbers of viral nucleocapsids and were easily distinguished from other swollen cisternae such as those after the block. These intracellular capsid-binding membranes (ICBMs) were not stained by cytochemical markers for endoplasmic reticulum (ER) (glucose-6-phosphatase) or trans Golgi cisternae (thiamine pyrophosphatase, acid phosphatase) but were labeled by Ricinus communis agglutinin I (RCA) in thin, frozen sections. Since this lectin labels only Golgi cisternae in the middle and on the trans side of the stack (Griffiths, G., R. Brands, B. Burke, D. Louvard, and G. Warren, 1982, J. Cell Biol., 95:781-792), we conclude that ICBMs are derived from Golgi cisternae in the middle of the stack, which we term medial cisternae. The overall movement of viral membrane proteins appears to be from cis to trans Golgi cisternae (see reference above), so monensin would block movement from medial to the trans cisternae. It also blocked the trimming of the high-mannose oligosaccharides bound to the viral membrane proteins and their conversion to complex oligosaccharides. These functions presumably reside in trans Golgi cisternae. This is supported by data in the accompanying paper, in which we also show that fatty acids are covalently attached to the viral membrane proteins in the cis or medial cisternae. We suggest that the Golgi stack can be divided into three functionally distinct compartments, each comprising one or two cisternae. The viral membrane proteins, after leaving the ER, would all pass in sequence from the cis to the medial to the trans compartment.

scholarly journals Dissection of the Golgi complex. II. Density separation of specific Golgi functions in virally infected cells treated with monensin.

1983 ◽  
Vol 96 (3) ◽  
pp. 851-856 ◽  
Author(s):  
P Quinn ◽  
G Griffiths ◽  
G Warren
Keyword(s):  
Membrane Proteins ◽  
Intracellular Transport ◽  
Semliki Forest Virus ◽  
Viral Membrane ◽  
Golgi Stack ◽  
Galactosyl Transferase ◽  
Infected Cells ◽  
Cis And Trans

In the accompanying paper (Griffiths, G., P. Quinn, and G. Warren, 1983, J. Cell Biol., 96:835-850), we suggested that the Golgi stack could be divided into functionally distinct cis, medial, and trans compartments, each comprising one or two adjacent cisternae. These compartments were identified using Baby hamster kidney (BHK) cells infected with Semliki Forest virus (SFV) and treated with monensin. This drug blocked intracellular transport but not synthesis of the viral membrane proteins that were shown to accumulate in the medial cisternae. In consequence, these cisternae bound nucleocapsids. Here we show that this binding markedly increased the density of the medial cisternae and allowed us to separate them from cis and trans Golgi cisternae. A number of criteria were used to show that the intracellular capsid-binding membranes (ICBMs) observed in vivo were the same as those membranes sedimenting to a higher density in sucrose gradients in vitro, and this separation of cisternae was then used to investigate the distribution, within the Golgi stack, of some specific Golgi functions. After labeling for 2.5 min with [3H]palmitate, most of the fatty acid attached to viral membrane proteins was found in the ICBM fraction. Because the viral membrane proteins appear to move from cis to trans, this suggests that fatty acylation occurs in the cis or medial Golgi cisternae. In contrast, the distribution of alpha 1-2-mannosidase, an enzyme involved in trimming high-mannose oligosaccharides, and of galactosyl transferase, which is involved in the construction of complex oligosaccharides, was not affected by monensin treatment. Together with data in the accompanying paper, this would restrict these two Golgi functions to the trans cisternae. Our data strongly support the view that Golgi functions have specific and discrete locations within the Golgi stack.

Changes Occur in Plasma Membrane Turnover when K562 Leukemia Cells are Induced to Differentiate

1982 ◽  
Vol 40 ◽  
pp. 286-287
Author(s):  
L. M. Marshall
Keyword(s):  
Plasma Membrane ◽  
Membrane Proteins ◽  
Intracellular Transport ◽  
Parent Cell ◽  
Membrane Turnover ◽  
Coated Pits ◽  
Surface Distribution ◽  
Specific Proteins ◽  
Erythroleukemic Cell ◽  
Specific Membrane

A human erythroleukemic cell line, metabolically blocked in a late stage of erythropoiesis, becomes capable of differentiation along the normal pathway when grown in the presence of hemin. This process is characterized by hemoglobin synthesis followed by rearrangement of the plasma membrane proteins and culminates in asymmetrical cytokinesis in the absence of nuclear division. A reticulocyte-like cell buds from the nucleus-containing parent cell after erythrocyte specific membrane proteins have been sequestered into its membrane. In this process the parent cell faces two obstacles. First, to organize its erythrocyte specific proteins at one pole of the cell for inclusion in the reticulocyte; second, to reduce or abolish membrane protein turnover since hemoglobin is virtually the only protein being synthesized at this stage. A means of achieving redistribution and cessation of turnover could involve movement of membrane proteins by a directional lipid flow. Generation of a lipid flow towards one pole and accumulation of erythrocyte-specific membrane proteins could be achieved by clathrin coated pits which are implicated in membrane endocytosis, intracellular transport and turnover. In non-differentiating cells, membrane proteins are turned over and are random in surface distribution. If, however, the erythrocyte specific proteins in differentiating cells were excluded from endocytosing coated pits, not only would their turnover cease, but they would also tend to drift towards and collect at the site of endocytosis. This hypothesis requires that different protein species are endocytosed by the coated vesicles in non-differentiating than by differentiating cells.

scholarly journals Membrane traffic between secretory compartments is differentially affected during mitosis.

1990 ◽  
Vol 1 (5) ◽  
pp. 415-424 ◽  
Author(s):  
T Kreiner ◽  
H P Moore
Keyword(s):  
Plasma Membrane ◽  
Membrane Proteins ◽  
Secretory Pathway ◽  
Chinese Hamster Ovary Cells ◽  
Chinese Hamster ◽  
Membrane Traffic ◽  
Human Growth ◽  
Secretory Proteins ◽  
Viral Membrane ◽  
Mitotic Cells

Membrane traffic has been shown to be regulated during cell division. In particular, with the use of viral membrane proteins as markers, endoplasmic reticulum (ER)-to-Golgi transport in mitotic cells has been shown to be essentially blocked. However, the effect of mitosis on other steps in the secretory pathway is less clear, because an early block makes examination of following steps difficult. Here, we report studies on the functional characteristics of secretory pathways in mitotic mammalian tissue culture cells by the use of a variety of markers. Chinese hamster ovary cells were transfected with cDNAs encoding secretory proteins. Consistent with earlier results following viral membrane proteins, we found that the overall secretory pathway is nonfunctional in mitotic cells, and a major block to secretion is at the step between ER and Golgi: the overall rate of secretion of human growth hormone is reduced at least 10-fold in mitotic cells, and export of truncated vesicular stomatitis virus G protein from the ER is inhibited to about the same extent, as judged by acquisition of endoglycosidase H resistance. To ascertain the integrity of transport from the trans-Golgi to plasma membrane, we followed the secretion of sulfated glycosaminoglycan (GAG) chains, which are synthesized in the Golgi and thus are not subject to the earlier ER-to-Golgi block. GAG chains are valid markers for the pathway taken by constitutive secretory proteins; both protein secretion and GAG chain secretion are sensitive to treatment with n-ethyl-maleimide and monensin and are blocked at 19 degrees C. We found that the extent of GAG-chain secretion is not altered during mitosis, although the initial rate of secretion is reduced about twofold in mitotic compared with interphase cells. Thus, during mitosis, transport from the trans-Golgi to plasma membrane is much less hindered than ER-to-Golgi traffic. We conclude that transport steps are not affected to the same extent during mitosis.

scholarly journals Is cytochrome P-450 transported from the endoplasmic reticulum to the Golgi apparatus in rat hepatocytes?

1985 ◽  
Vol 101 (5) ◽  
pp. 1733-1740 ◽  
Author(s):  
A Yamamoto ◽  
R Masaki ◽  
Y Tashiro
Keyword(s):  
Endoplasmic Reticulum ◽  
Membrane Proteins ◽  
Golgi Apparatus ◽  
Intracellular Transport ◽  
Subcellular Fraction ◽  
Plasma Membranes ◽  
Rat Hepatocytes ◽  
Cytochrome P 450 ◽  
Microscopic Techniques ◽  
Lysosomal Proteins

The Golgi apparatus mediates intracellular transport of not only secretory and lysosomal proteins but also membrane proteins. As a typical marker membrane protein for endoplasmic reticulum (ER) of rat hepatocytes, we have selected phenobarbital (PB)-inducible cytochrome P-450 (P-450[PB]) and investigated whether P-450(PB) is transported to the Golgi apparatus or not by combining biochemical and quantitative ferritin immunoelectron microscopic techniques. We found that P-450(PB) was not detectable on the membrane of Golgi cisternae either when P-450 was maximally induced by phenobarbital treatment or when P-450 content in the microsomes rapidly decreased after cessation of the treatment. The P-450 detected biochemically in the Golgi subcellular fraction can be explained by the contamination of the microsomal vesicles derived from fragmented ER membranes to the Golgi fraction. We conclude that when the transfer vesicles are formed by budding on the transitional elements of ER, P-450 is completely excluded from such regions and is not transported to the Golgi apparatus, and only the membrane proteins destined for the Golgi apparatus, plasma membranes, or lysosomes are selectively collected and transported.

scholarly journals The trans Golgi Network Is Lost from Cells Infected with African Swine Fever Virus

2001 ◽  
Vol 75 (23) ◽  
pp. 11755-11765 ◽  
Author(s):  
Mari McCrossan ◽  
Miriam Windsor ◽  
Sreenivasan Ponnambalam ◽  
John Armstrong ◽  
Thomas Wileman
Keyword(s):  
Membrane Proteins ◽  
Secretory Pathway ◽  
African Swine Fever Virus ◽  
African Swine Fever ◽  
Fever Virus ◽  
Host Proteins ◽  
Viral Membrane ◽  
Membrane Compartments ◽  
Hydrophobic Amino Acids ◽  
Golgi Network

ABSTRACT The cellular secretory pathway is important during the assembly and envelopment of viruses and also controls the transport of host proteins, such as cytokines and major histocompatibility proteins, that function during the elimination of viruses by the immune system. African swine fever virus (ASFV) encodes at least 26 proteins with stretches of hydrophobic amino acids suggesting entry into the secretory pathway (R. J. Yanez, J. M. Rodriguez, M. L. Nogal, L. Yuste, C. Enriquez, J. F. Rodriguez, and E. Vinuela, Virology 208:249–278, 1995). To predict how and where these potential membrane proteins function, we have studied the integrity of the secretory pathway in cells infected with ASFV. Remarkably, ASFV caused complete loss of immunofluorescence signal for the trans Golgi network (TGN) marker protein TGN46 and dispersed the AP1 TGN adapter complex. Loss of TGN46 signal was not due to degradation of TGN46, suggesting redistribution of TGN46 to other membrane compartments. ASFV markedly slowed transport of cathepsin D to lysosomes, demonstrating that loss of TGN structure correlated with loss of TGN function. ASFV shows a tropism for macrophages, and it is possible that ASFV compromises TGN function to augment the activity of viral membrane proteins or to suppress the function of host immunoregulatory proteins.

scholarly journals Coupling of viral membrane proteins to phosphatidylinositide signalling system

FEBS Letters ◽  
1989 ◽  
Vol 247 (2) ◽  
pp. 185-188 ◽  
Author(s):  
Christa Weinmann-Dorsch ◽  
Klaus Koschel
Keyword(s):  
Membrane Proteins ◽  
Viral Membrane ◽  
Signalling System
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