Colchicine-binding sites of brain tubulins from an Antarctic fish and from a mammal are functionally similar, but not identical: Implications for microtubule assembly at low temperature

1992 ◽  
Vol 21 (4) ◽  
pp. 272-280 ◽  
Author(s):  
Dimitrios A. Skoufias ◽  
Leslie Wilson ◽  
H. William Detrich
Keyword(s):  
Low Temperature ◽  
Binding Sites ◽  
Antarctic Fish ◽  
Microtubule Assembly

Formation of microtubules at low temperature by tubulin from Antarctic fish

Biochemistry ◽  
1985 ◽  
Vol 24 (11) ◽  
pp. 2790-2798 ◽  
Author(s):  
Robley C. Williams ◽  
John J. Correia ◽  
Arthur L. De Vries
Keyword(s):  
Low Temperature ◽  
Antarctic Fish

Immunoreactive atrial natriuretic peptide and autoradiographic distribution of atrial natriuretic peptide binding sites in the brain of the Antarctic fish, Chionodraco hamatus

Polar Biology ◽  
2000 ◽  
Vol 23 (10) ◽  
pp. 691-698 ◽  
Author(s):  
Mario Pestarino ◽  
Simona Candiani ◽  
Maria Angela Masini ◽  
Maddalena Sturla ◽  
Andrea Augello ◽  
...  
Keyword(s):  
Atrial Natriuretic Peptide ◽  
Natriuretic Peptide ◽  
Binding Sites ◽  
Peptide Binding ◽  
Antarctic Fish ◽  
The Antarctic ◽  
The Brain ◽  
Atrial Natriuretic

scholarly journals Microtubule assembly kinetics. Changes with solution conditions

1987 ◽  
Vol 247 (3) ◽  
pp. 505-511 ◽  
Author(s):  
J S Barton ◽  
D L Vandivort ◽  
D H Heacock ◽  
J A Coffman ◽  
K A Trygg
Keyword(s):  
Activation Energy ◽  
Ionic Strength ◽  
Low Temperature ◽  
Number Concentration ◽  
High Ionic Strength ◽  
Microtubule Assembly ◽  
Microtubule Protein ◽  
Assembly Kinetics ◽  
Low Ionic Strength ◽  
Kinetics Of

The assembly kinetics of microtubule protein are altered by ionic strength, temperature and Mg2+, but not by pH. High ionic strength (I0.2), low temperature (T less than 30 degrees C) and elevated Mg2+ (greater than or equal to 1.2 mM) induce a transition from biphasic to monophasic kinetics. Comparison of the activation energy obtained for the fast biphasic step at low ionic strength (I0.069) shows excellent agreement with the values obtained at high ionic strength, low temperature and elevated Mg2+. From this observation it can be implied that the tubulin-containing reactant of the fast biphasic event is also the species that elongates microtubules during monophasic assembly. Second-order rate constants for biphasic assembly are 3.82(+/- 0.72) x 10(7) M-1.s-1 and 5.19(+/- 1.25) x 10(6) M-1.s-1, and for monophasic assembly the rate constant is 2.12(+/- 0.56) x 10(7) M-1.s-1. The microtubule number concentration is constant during elongation of microtubules for biphasic and monophasic assembly.

scholarly journals Oculomotor function at low temperature: antarctic versus temperate fish

1985 ◽  
Vol 117 (1) ◽  
pp. 181-191
Author(s):  
J. C. Montgomery ◽  
J. A. Macdonald
Keyword(s):  
Low Temperature ◽  
Eye Movement ◽  
Characteristic Frequency ◽  
Temperature Compensation ◽  
Antarctic Fish ◽  
Abducens Nerve ◽  
Oculomotor System ◽  
Temperature Function ◽  
Movement Characteristic ◽  
Temperate Fish

The peripheral oculomotor system can be modelled as a first order linear system (Montgomery, 1983), and hence specified by its characteristic frequency and ‘d.c.’ gain. These parameters can be determined by recording eye movements produced by stimulation of the abducens nerve with sinusoidally modulated pulse trains, and compare well with those independently derived from the relationship between motoneurone firing and spontaneous eye movement. Characteristic frequency and gain of the peripheral oculomotor system were determined for two species of antarctic teleost and one temperate species, to examine temperature compensation within a complete motor output pathway. Compared with low temperature function in temperate fish, the characteristic frequency is clearly temperature compensated in antarctic fish, which explains in part the observed temperature compensation of their rapid eye movement. The ‘d.c.’ gain of the peripheral oculomotor system is inversely related to temperature, providing an automatic compensation for possible reductions in central nervous system output and sensory gain at low temperature.

Endocytosis in proximal tubule cells involves a two-phase membrane-recycling pathway

1993 ◽  
Vol 264 (4) ◽  
pp. C823-C835 ◽  
Author(s):  
S. Nielsen
Keyword(s):  
Plasma Membrane ◽  
Low Temperature ◽  
Proximal Tubule ◽  
Binding Sites ◽  
Membrane Recycling ◽  
Two Phase ◽  
Proximal Tubule Cells ◽  
Recycling Pathway ◽  
Tubule Cells ◽  
Endocytic Vesicles

The aims of the present study were to examine the initial events of endocytosis with respect to migration, internalization, and recycling of protein binding sites on the luminal plasma membrane of genuine renal proximal tubule cells (not cultured cells), and in particular the sequential involvement of dense apical tubules (DAT). Isolated rabbit proximal tubules were first perfused at low temperature (9 degrees C) with insulin-gold to label the binding sites and then with disuccinimidyl suberate (DSS) for 20 min to covalently cross-link insulin-gold and binding sites. The tubules were subsequently perfused for 4-30 min at 25 or 37 degrees C before fixation to follow the pathways of the binding sites. The present experimental approach allowed a temporal separation of the subcellular processes involved in endocytosis. The identity and organization of the different organelles were certified by serial sectioning of the experimental tubules. In tubules fixed directly at low temperature after cross-linking the label was located on the microvilli membranes and in plasma membrane invaginations. The labeling of microvilli decreased with time of perfusion at 25 degrees C in parallel with a simultaneous increase of labeling of invaginations, suggesting lateral migration of the binding sites. The invaginations pinched off from the surface to form endocytic vesicles. The binding sites were subsequently trafficked either to 1) tubular elongations from endocytic vesicles or small vacuoles, which again form DAT, or 2) in a later sequence trafficked to larger vacuoles, from which tubular elongations and DAT also form. The elongations formed the DAT that transported binding sites back to the luminal plasma membrane. Lysosomes and Golgi apparatus were not involved in membrane recycling. Thus the present study provides evidence for a two-phase recycling pathway of membrane proteins involved in endocytosis.

scholarly journals Concanavalin A induces microtubule assembly and specific granule discharge in human polymorphonuclear leukocytes.

1976 ◽  
Vol 68 (3) ◽  
pp. 781-787 ◽  
Author(s):  
S Hoffstein ◽  
R Soberman ◽  
I Goldstein ◽  
G Weissmann
Keyword(s):  
Concanavalin A ◽  
Binding Sites ◽  
Polymorphonuclear Leukocytes ◽  
Cytochalasin B ◽  
Microtubule Assembly ◽  
Human Neutrophils ◽  
Con A ◽  
Specific Granules ◽  
Specific Granule ◽  
Human Polymorphonuclear Leukocytes

Human neutrophils stimulated by concanavalin A (Con A, 100 microng/ml) contained markedly enhanced numbers of microtubules and discharged peroxidase-negative (specific) but not peroxidase-position (azurophile) granules. Release of lysozyme from specific granules was dose and time dependent, could be inhibitied by alpha-methyl-D-mannoside, and enhanced by cytochalasin B. Many microtubules were associated with internalized plasma membrane bearing Con A binding sites.

Cold adaptation in marine organisms

1990 ◽  
Vol 326 (1237) ◽  
pp. 655-667 ◽  
Keyword(s):  
Low Temperature ◽  
Freezing Point ◽  
Extracellular Fluid ◽  
Antarctic Fish ◽  
Marine Species ◽  
Marine Organisms ◽  
Freezing Injury ◽  
Tropical Species ◽  
Diverse Range ◽  
Fluid Compartments

Animals from polar seas exhibit numerous so called resistance adaptations that serve to maintain homeostasis at low temperature and prevent lethal freezing injury. Specialization to temperatures at or below 0 °C is associated with an inability to survive at temperatures above 3-8 °C. Polar fish synthesize various types of glycoproteins or peptides to lower the freezing point of most extracellular fluid compartments in a non-colligative manner. Antifreeze production is seasonal in boreal species and is often initiated by environmental cues other than low temperature, particularly short day lengths. Most of the adaptations that enable intertidal invertebrates to survive freezing are associated with their ability to withstand ariel exposure. Unique adaptations for freezing avoidance include the synthesis of low molecular mass ice-nucleating proteins that control and induce extracellular ice-formation. Marine poikilotherms also exhibit a range of capacity adaptations that increase the rate of some physiological processes so as to partially compensate for the effects of low temperature. However, the rate of embryonic development in a diverse range of marine organisms shows no evidence of temperature compensation. This results in a significant lengthening of the time from fertilization to hatching in polar, relative to temperate, species. Some aspects of the physiology of polar marine species, such as low metabolic and slow growth rates, probably result from a combination of low temperature and other factors such as the highly seasonal nature of food supplies. Although neuromuscular function shows a partial capacity adaptation in Antarctic fish, maximum swimming speeds are lower than for temperate and tropical species, particularly for early stages in the life history.

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