The Effects of Microcystins (Cyanobacterial Heptapeptides) on the Eukaryotic Cytoskeletal System

2016 ◽  
Vol 16 (13) ◽  
pp. 1063-1077 ◽  
Author(s):  
Csaba Máthé ◽  
Dániel Beyer ◽  
Márta M-Hamvas ◽  
Gábor Vasas
Keyword(s):  
Cytoskeletal System

Effect of verapamil on cytoplasmic distribution of granules and microfilaments in amphibian urinary bladder

1988 ◽  
Vol 46 ◽  
pp. 324-325
Author(s):  
A.J. Mia ◽  
L.X. Oakford ◽  
T. Yorio
Keyword(s):  
Urinary Bladder ◽  
Water Flow ◽  
Morphological Changes ◽  
Granular Cell ◽  
Cytosolic Calcium ◽  
Calcium Storage ◽  
Amphibian Urinary Bladder ◽  
Vesicular Membrane ◽  
High Concentrations ◽  
Cytoskeletal System

The amphibian urinary bladder has been used as a ‘model’ system for studies of the mechanism of action of antidiuretic hormone (ADH) in stimulating transepithelial water flow. The increase in water permeability is accompanied by morphological changes that include the stimulation of apical microvilli, mobilization of microtubules and microfilaments and vesicular membrane fusion events . It has been shown that alterations in the cytosolic calcium concentrations can inhibit ADH transmembrane water flow and induce alterations in the epithelial cell cytomorphology, including the cytoskeletal system . Recently, the subapical granules of the granular cell in the amphibian urinary bladder have been shown to contain high concentrations of calcium, and it was suggested that these cytoplasmic constituents may act as calcium storage sites for intracellular calcium homeostasis. The present study utilizes the calcium antagonist, verapamil, to examine the effect of calcium deprivation on the cytomorphological features of epithelial cells from amphibian urinary bladder, with particular emphasis on subapical granule and microfilament distribution.

Intermediate Filament Cytoskeletal System: Dynamic and Mechanical Properties

1998 ◽  
Vol 194 (3) ◽  
pp. 361-363 ◽  
Author(s):  
R. D. Goldman ◽  
S. Clement ◽  
S. Khuon ◽  
R. Moir ◽  
A. Trejo-Skalli ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Intermediate Filament ◽  
System Dynamic ◽  
Cytoskeletal System

Intermediate Filament and Associated Proteins in Heart Purkinje Fibers: A Membrane-Myofibril Anchored Cytoskeletal System

1985 ◽  
Vol 455 (1 Intermediate) ◽  
pp. 213-240 ◽  
Author(s):  
LARS-ERIC THORNELL ◽  
ANDERS ERIKSSON ◽  
BENGT JOHANSSON ◽  
UNO KJÖRELL ◽  
WERNER W. FRANKE ◽  
...  
Keyword(s):  
Intermediate Filament ◽  
Purkinje Fibers ◽  
Associated Proteins ◽  
Cytoskeletal System

The Dynamics of Aqueous Humor Outflow—A Major Review

2014 ◽  
Vol 07 (02) ◽  
pp. 137 ◽  
Author(s):  
Syed Shoeb Ahmad ◽  
Shuaibah Abdul Ghani ◽  
Daljit Singh ◽  
Lott Pooi Wah ◽  
◽  
...  
Keyword(s):  
Aqueous Humor ◽  
Intracellular Signaling ◽  
Open Angle Glaucoma ◽  
Rho Kinase ◽  
Aqueous Humor Outflow ◽  
Aqueous Humor Dynamics ◽  
Complex Organization ◽  
Biochemical Mechanisms ◽  
Major Review ◽  
Cytoskeletal System

Aqueous humor outflow occurs through the conventional and unconventional pathway. With aging, the latter becomes less active so that the conventional pathway remains the primary mechanism of aqueous humor outflow. An abnormality of this pathway contributes significantly to disordered aqueous humor dynamics and consequent rise in intraocular pressure seen in primary open angle glaucoma and ocular hypertension. Recently, the ocular lymphatics have been implicated in aqueous humor outflow. Additionally, the trabecular meshwork is now understood to be a complex organization of structures, which are controlled by various biomechanical and biochemical mechanisms. Among others, these include the actinomyosin cytoskeletal system, extracellular matrix, intracellular signaling responses mediated by protein kinase C, Rho/Rho kinase, and other biologic factors. This review shall describe the various pathophysiologic mechanisms involved in aqueous humor dynamics.

scholarly journals AN ULTRASTRUCTURAL STUDY OF PLANT SPERMATOGENESIS

1968 ◽  
Vol 37 (2) ◽  
pp. 370-393 ◽  
Author(s):  
F. R. Turner
Keyword(s):  
Electron Microscopy ◽  
Golgi Apparatus ◽  
Ultrastructural Study ◽  
Light And Electron Microscopy ◽  
Mature Sperm ◽  
Basal Bodies ◽  
Animal Cells ◽  
Early Spermatid ◽  
And Behavior ◽  
Cytoskeletal System

Spermatogenesis in the charophyte Nitella has been followed in antheridia prepared for light and electron microscopy. The antheridial filament cells contain paired centrioles which are similar in structure and behavior to the centrioles of animal cells. In the early spermatid, the centrioles undergo an initial elongation at their distal ends and become joined by a spindle-shaped fibrous connection. At the same time, their proximal ends are closely associated with the development of a layer of juxtaposed microtubules which will form the microtubular sheath. The architectural arrangement of these microtubules suggests that they constitute a cytoskeletal system, forming a framework along which the mitochondria and plastids become aligned and along which the nucleus undergoes extensive elongation and differentiation. The microtubular sheath persists in the mature sperm. During mid-spermatid stages, the centrioles give rise to the flagella and concomitantly undergo differentiation to become the basal bodies. The Golgi apparatus goes through a period of intensive activity during mid-spermatid stages, then decreases in organization until it can no longer be detected in the late spermatid. An attempt is made to compare similarities between plant and animal spermiogenesis.

scholarly journals Biosynthesis of spectrin and its assembly into the cytoskeletal system of Friend erythroleukemia cells.

1986 ◽  
Vol 103 (1) ◽  
pp. 103-113 ◽  
Author(s):  
S R Pfeffer ◽  
T Huima ◽  
C M Redman
Keyword(s):  
Dimethyl Sulfoxide ◽  
Soluble Fraction ◽  
Insoluble Fraction ◽  
Cell Fraction ◽  
Erythroleukemia Cells ◽  
Alpha Spectrin ◽  
Membrane Bound ◽  
Friend Erythroleukemia Cells ◽  
Cytoskeletal System ◽  
In Cells

Friend erythroleukemia cells, grown in the presence of dimethyl sulfoxide for 3 d, synthesize unequal amounts of the two chains (alpha and beta) of spectrin with approximately 15-30% more beta than alpha spectrin. When cells were ruptured by nitrogen cavitation, nascent alpha and beta spectrin were found to be associated with a membranous cell fraction and were not detected in the soluble cytoplasmic cell fraction. Nascent membrane-bound spectrin appeared not to be protected by membranes, since it was susceptible to trypsin degradation in the absence of detergent. On fractionation of cells with 1% Triton X-100, more (1.75-fold) nascent spectrin was found in the Triton-soluble fraction than in the Triton-insoluble fraction (cytoskeleton). In the Triton-soluble fraction, there was 55% more nascent beta spectrin than alpha spectrin, while the cytoskeleton contained nearly equal amounts of alpha and beta spectrin. Cells were pulse-labeled with L-[35S]methionine for 2 min and chase incubated for varying periods of time from 15 to 90 min with nonradioactive L-methionine. Radioactive spectrin accumulated in the Triton-soluble fraction for the first 15 min of chase incubation and then dropped by 25% in the next hour. By contrast, the amount of radioactive spectrin in the Triton-insoluble fraction rose gradually for 1 h of the chase period. This indicates that, in Friend erythroleukemia cells, a pool of membrane-bound spectrin containing an excess of the beta polypeptide is used to form the cytoskeletal system which is composed of equal molar amounts of alpha and beta spectrin. The location of spectrin was determined by immunoelectron microscopy. Small amounts of spectrin were detected in cells not treated with dimethyl sulfoxide and in these cells it was located on the surface membrane and within the cytoplasm. On treatment with dimethyl sulfoxide, complex vacuolar structures containing viruses appeared in the cells. In cells treated with dimethyl sulfoxide for 3 d 30% of the spectrin was near the outer membrane and 25% was associated with vacuolar structures, whereas in cells treated for 5 and 7 d the majority of spectrin (57-61%) was located in the vacuolar areas.

scholarly journals H+- and Na+-elicited swift changes of the microtubule system in the biflagellated green alga Chlamydomonas

2017 ◽  
Author(s):  
Yi Liu ◽  
Mike Visetsouk ◽  
Michelle Mynlieff ◽  
Hongmin Qin ◽  
Karl F. Lechtreck ◽  
...  
Keyword(s):  
Real Time ◽  
Fresh Water ◽  
Green Alga ◽  
Dynamic Instability ◽  
Animal Cells ◽  
Reporter Protein ◽  
Fluorescent Reporter ◽  
Cellular Processes ◽  
Endogenous Level ◽  
Cytoskeletal System

AbstractThe microtubule cytoskeletal system is integral to diverse cellular processes. Although microtubules are known for dynamic instability, the system is tightly controlled in typical interphase animal cells. In contrast, diverse evidence suggests that the system is mercurial in the unicellular fresh water green alga, Chlamydomonas, but intense autofluorescence from photosynthesis pigments has hindered the investigation. By expressing a bright fluorescent reporter protein at the endogenous level, we demonstrate in real time discreet sweeping changes in algal microtubules elicited by fluctuation of intracellular H+ and Na+. These results suggest disparate sensitivity of this vital yet delicate system in diverse organisms; and illuminate how pH may drive crucial cellular processes; how plants respond to, and perhaps sense stresses; and how many species could be susceptible to accelerated changes in global environments.

scholarly journals Septins Coordinate with Microtubules and Actin to Initiate Cell Morphogenesis

2019 ◽  
Author(s):  
Diana Bogorodskaya ◽  
Lee A. Ligon
Keyword(s):  
Branching Morphogenesis ◽  
Response To Treatment ◽  
Cell Morphogenesis ◽  
Microtubule Organization ◽  
Basal Surface ◽  
Linear Rate ◽  
Epithelial Sheet ◽  
District Role ◽  
Hepatocyte Growth ◽  
Cytoskeletal System

AbstractMany organs are formed by a process of branching morphogenesis, which begins with the formation of cytoplasmic extensions from the basal surface of polarized cells in an epithelial sheet. To study this process, we used a system of polarized epithelial spheroids, which emit cytoplasmic extensions in response to treatment with hepatocyte growth factor. We found that these extensions contain both actin and microtubules, but also septins, which are localized to microtubule bundles and appear to be important in maintaining microtubule organization. We found that these extensions are highly dynamic and form at a non-linear rate. We also demonstrated that the coordinated activity of microtubules, actin, and septins is necessary for the formation and dynamic behavior of extensions. Each cytoskeletal system plays a district role in this process, with microtubules enabling persistent growth of the extensions, actin enabling extension dynamics, and septins organizing microtubules in the extensions and supporting the extension formation. Together, our data offer insights into the dynamics of early morphogenic extensions and the distinct, but coordinated, roles of cytoskeleton in early morphogenesis.

Sign in / Sign up

Export Citation Format

Share Document