Nobel prize is awarded for studies of intracellular transport mechanisms

BMJ ◽  
2013 ◽  
Vol 347 (oct08 2) ◽  
pp. f6087-f6087
Author(s):  
G. Watts
Keyword(s):  
Nobel Prize ◽  
Intracellular Transport ◽  
Transport Mechanisms

Pathogenesis of Reye's Syndrome: A Working Hypothesis

PEDIATRICS ◽  
1975 ◽  
Vol 56 (6) ◽  
pp. 1081-1084
Author(s):  
M. Michael Thaler
Keyword(s):  
Fatty Liver ◽  
Intracellular Transport ◽  
Urea Cycle ◽  
Transport Mechanisms ◽  
Reye's Syndrome ◽  
Specific Therapy ◽  
Ammonia Metabolism ◽  
History Of ◽  
Urea Cycle Enzymes

The brief history of Reye's syndrome has been one of progressive familiarity with a deepening mystery. It is possible that the syndrome reflects a variety of etiologically unrelated conditions with similar clinicopathological manifestations. In this view, subclinical defects in ammonia metabolism may constitute a distinct, identifiable group among disorders responsible for encephalopathy with fatty liver. Awareness of the possible role of mutant urea cycle enzymes and deficient substrates in the pathogenesis of this important illness should stimulate investigations of enzyme kinetics and intracellular transport mechanisms which may reveal a spectrum of abnonmalities in ammonia metabolism-and a specific therapy for each.

scholarly journals Influenza Virus-Induced Caspase-Dependent Enlargement of Nuclear Pores Promotes Nuclear Export of Viral Ribonucleoprotein Complexes

2015 ◽  
Vol 89 (11) ◽  
pp. 6009-6021 ◽  
Author(s):  
Dirk Mühlbauer ◽  
Julia Dzieciolowski ◽  
Martin Hardt ◽  
Andreas Hocke ◽  
Kristina L. Schierhorn ◽  
...  
Keyword(s):  
Influenza Virus ◽  
Nuclear Export ◽  
Intracellular Transport ◽  
Infectious Virus ◽  
Replication Cycle ◽  
Nuclear Pore ◽  
Transport Mechanisms ◽  
Nuclear Pores ◽  
Ribonucleoprotein Complexes ◽  
Infected Cells

ABSTRACTInfluenza A viruses (IAV) replicate their segmented RNA genome in the nucleus of infected cells and utilize caspase-dependent nucleocytoplasmic export mechanisms to transport newly formed ribonucleoprotein complexes (RNPs) to the site of infectious virion release at the plasma membrane. In this study, we obtained evidence that apoptotic caspase activation in IAV-infected cells is associated with the degradation of the nucleoporin Nup153, an integral subunit of the nuclear pore complex. Transmission electron microscopy studies revealed a distinct enlargement of nuclear pores in IAV-infected cells. Transient expression and subcellular accumulation studies of multimeric marker proteins in virus-infected cells provided additional evidence for increased nuclear pore diameters facilitating the translocation of large protein complexes across the nuclear membrane. Furthermore, caspase 3/7 inhibition data obtained in this study suggest that active, Crm1-dependent IAV RNP export mechanisms are increasingly complemented by passive, caspase-induced export mechanisms at later stages of infection.IMPORTANCEIn contrast to the process seen with most other RNA viruses, influenza virus genome replication occurs in the nucleus (rather than the cytoplasm) of infected cells. Therefore, completion of the viral replication cycle critically depends on intracellular transport mechanisms that ensure the translocation of viral ribonucleoprotein (RNP) complexes across the nuclear membrane. Here, we demonstrate that virus-induced cellular caspase activities cause a widening of nuclear pores, thereby facilitating nucleocytoplasmic translocation processes and, possibly, promoting nuclear export of newly synthesized RNPs. These passive transport mechanisms are suggested to complement Crm1-dependent RNP export mechanisms known to occur at early stages of the replication cycle and may contribute to highly efficient production of infectious virus progeny at late stages of the viral replication cycle. The report provides an intriguing example of how influenza virus exploits cellular structures and regulatory pathways, including intracellular transport mechanisms, to complete its replication cycle and maximize the production of infectious virus progeny.

Intracellular transport mechanisms: a critique of diffusion theory

1995 ◽  
Vol 176 (2) ◽  
pp. 261-272 ◽  
Author(s):  
P.S. Agutter ◽  
P.C. Malone ◽  
D.N. Wheatley
Keyword(s):  
Intracellular Transport ◽  
Diffusion Theory ◽  
Transport Mechanisms

Physical Properties of Isolated Perfused Renal Tubular Basement Membranes

1971 ◽  
Vol 29 ◽  
pp. 390-391
Author(s):  
Jared Grantham ◽  
Larry Welling
Keyword(s):  
Basement Membrane ◽  
Basement Membranes ◽  
Transport Mechanisms ◽  
Permeability Characteristics ◽  
Peritubular Capillaries ◽  
Strategic Location ◽  
Tubular Lumen ◽  
Glomerular Filtrate ◽  
Urine Formation ◽  
Renal Tubular

In the course of urine formation in mammalian kidneys over 90% of the glomerular filtrate moves from the tubular lumen into the peritubular capillaries by both active and passive transport mechanisms. In all of the morphologically distinct segments of the renal tubule, e.g. proximal tubule, loop of Henle and distal nephron, the tubular absorbate passes through a basement membrane which rests against the basilar surface of the epithelial cells. The basement membrane is in a strategic location to affect the geometry of the tubules and to influence the movement of tubular absorbate into the renal interstitium. In the present studies we have determined directly some of the mechanical and permeability characteristics of tubular basement membranes.

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.

Confocal microscopy of the cytoskeleton in living plant cells following microinjection of fluorescent probes

1993 ◽  
Vol 51 ◽  
pp. 130-131
Author(s):  
Ann Cleary
Keyword(s):  
Cell Division ◽  
Fluorescent Probes ◽  
Actin Filaments ◽  
Intracellular Transport ◽  
Cell Structure ◽  
Plant Cells ◽  
Cell Plate ◽  
Cell Cortex ◽  
Living Plant ◽  
Rhodamine Phalloidin

Microinjection of fluorescent probes into living plant cells reveals new aspects of cell structure and function. Microtubules and actin filaments are dynamic components of the cytoskeleton and are involved in cell growth, division and intracellular transport. To date, cytoskeletal probes used in microinjection studies have included rhodamine-phalloidin for labelling actin filaments and fluorescently labelled animal tubulin for incorporation into microtubules. From a recent study of Tradescantia stamen hair cells it appears that actin may have a role in defining the plane of cell division. Unlike microtubules, actin is present in the cell cortex and delimits the division site throughout mitosis. Herein, I shall describe actin, its arrangement and putative role in cell plate placement, in another material, living cells of Tradescantia leaf epidermis.The epidermis is peeled from the abaxial surface of young leaves usually without disruption to cytoplasmic streaming or cell division. The peel is stuck to the base of a well slide using 0.1% polyethylenimine and bathed in a solution of 1% mannitol +/− 1 mM probenecid.

Alveolobronchiolar transport mechanisms

1973 ◽  
Vol 131 (1) ◽  
pp. 109-114 ◽  
Author(s):  
G. M. Green
Keyword(s):  
Transport Mechanisms
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