Role of auxin and cytokinin in the regulation of the actin cytoskeleton in the in vitro germinating male gametophyte of petunia

2015 ◽  
Vol 62 (2) ◽  
pp. 179-186 ◽  
Author(s):  
L. V. Kovaleva ◽  
A. S. Voronkov ◽  
E. V. Zakharova
Keyword(s):  
Actin Cytoskeleton ◽  
Male Gametophyte

scholarly journals Protein Analysis of Pollen Tubes after the Treatments of Membrane Trafficking Inhibitors Gains Insights on Molecular Mechanism Underlying Pollen Tube Polar Growth

2021 ◽  
Vol 40 (2) ◽  
pp. 205-222
Author(s):  
Monica Scali ◽  
Alessandra Moscatelli ◽  
Luca Bini ◽  
Elisabetta Onelli ◽  
Rita Vignani ◽  
...  
Keyword(s):  
Pollen Tube ◽  
Actin Cytoskeleton ◽  
Membrane Trafficking ◽  
Tip Growth ◽  
Male Gametophyte ◽  
Pollen Tubes ◽  
Structural Features ◽  
Two Dimensional Gel Electrophoresis ◽  
Depth Analysis

AbstractPollen tube elongation is characterized by a highly-polarized tip growth process dependent on an efficient vesicular transport system and largely mobilized by actin cytoskeleton. Pollen tubes are an ideal model system to study exocytosis, endocytosis, membrane recycling, and signaling network coordinating cellular processes, structural organization and vesicular trafficking activities required for tip growth. Proteomic analysis was applied to identifyNicotiana tabacumDifferentially Abundant Proteins (DAPs) after in vitro pollen tube treatment with membrane trafficking inhibitors Brefeldin A, Ikarugamycin and Wortmannin. Among roughly 360 proteins separated in two-dimensional gel electrophoresis, a total of 40 spots visibly changing between treated and control samples were identified by MALDI-TOF MS and LC–ESI–MS/MS analysis. The identified proteins were classified according to biological processes, and most proteins were related to pollen tube energy metabolism, including ammino acid synthesis and lipid metabolism, structural features of pollen tube growth as well modification and actin cytoskeleton organization, stress response, and protein degradation. In-depth analysis of proteins corresponding to energy-related pathways revealed the male gametophyte to be a reliable model of energy reservoir and dynamics.

Force-dependent vinculin binding to talin in live cells: a crucial step in anchoring the actin cytoskeleton to focal adhesions

2014 ◽  
Vol 306 (6) ◽  
pp. C607-C620 ◽  
Author(s):  
Hiroaki Hirata ◽  
Hitoshi Tatsumi ◽  
Chwee Teck Lim ◽  
Masahiro Sokabe
Keyword(s):  
Actin Cytoskeleton ◽  
Focal Adhesions ◽  
Living Cells ◽  
Live Cells ◽  
Mechanical Forces ◽  
Actin Network ◽  
Crucial Step

Mechanical forces play a pivotal role in the regulation of focal adhesions (FAs) where the actin cytoskeleton is anchored to the extracellular matrix through integrin and a variety of linker proteins including talin and vinculin. The localization of vinculin at FAs depends on mechanical forces. While in vitro studies have demonstrated the force-induced increase in vinculin binding to talin, it remains unclear whether such a mechanism exists at FAs in vivo. In this study, using fibroblasts cultured on elastic silicone substrata, we have examined the role of forces in modulating talin-vinculin binding at FAs. Stretching the substrata caused vinculin accumulation at talin-containing FAs, and this accumulation was abrogated by expressing the talin-binding domain of vinculin (domain D1, which inhibits endogenous vinculin from binding to talin). These results indicate that mechanical forces loaded to FAs facilitate vinculin binding to talin at FAs. In cell-protruding regions, the actin network moved backward over talin-containing FAs in domain D1-expressing cells while it was anchored to FAs in control cells, suggesting that the force-dependent vinculin binding to talin is crucial for anchoring the actin cytoskeleton to FAs in living cells.

scholarly journals Isoflurane Impairs Immature Astroglia Development In Vitro: The Role of Actin Cytoskeleton

2011 ◽  
Vol 70 (4) ◽  
pp. 281-291 ◽  
Author(s):  
Nadia Lunardi ◽  
Christoph Hucklenbruch ◽  
Janelle R. Latham ◽  
Joseph Scarpa ◽  
Vesna Jevtovic-Todorovic
Keyword(s):  
Actin Cytoskeleton ◽  
Development In Vitro

scholarly journals CaMKIIβ Association with the Actin Cytoskeleton Is Regulated by Alternative Splicing

2006 ◽  
Vol 17 (11) ◽  
pp. 4656-4665 ◽  
Author(s):  
Heather O'Leary ◽  
Erika Lasda ◽  
K. Ulrich Bayer
Keyword(s):  
Skeletal Muscle ◽  
Nervous System ◽  
Alternative Splicing ◽  
Actin Cytoskeleton ◽  
Actin Filaments ◽  
Kinase Activity ◽  
Dependent Protein Kinase ◽  
Dependent Protein

The Ca2+/calmodulin (CaM)-dependent protein kinase II (CaMKII)β has morphogenic functions in neurons not shared by the α isoform. CaMKIIβ contains three exons (v1, v3, and v4) not present in the CaMKIIα gene, and two of these exons (v1 and v4) are subject to differential alternative splicing. We show here that CaMKIIβ, but not α, mediated bundling of F-actin filaments in vitro. Most importantly, inclusion of exon v1 was required for CaMKIIβ association with the F-actin cytoskeleton within cells. CaMKIIβe, which is the dominant variant around birth and lacks exon v1 sequences, failed to associate with F-actin. By contrast, CaMKIIβ′, which instead lacks exon v4, associated with F-actin as full-length CaMKIIβ. Previous studies with CaMKIIβ mutants have indicated a role of nonstimulated kinase activity in enhancing dendritic arborization. Here, we show that F-actin–targeted CaMKIIβ, but not α, was able to phosphorylate actin in vitro even by nonstimulated basal activity in absence of Ca2+/CaM. In rat pancreatic islets and in skeletal muscle, the actin-associated CaMKIIβ′ and βM were the predominant variants, respectively. Thus, cytoskeletal targeting may mediate functions of CaMKIIβ variants also outside the nervous system.

Effects of cadmium on the actin cytoskeleton in renal mesangial cells

2013 ◽  
Vol 91 (1) ◽  
pp. 1-7 ◽  
Author(s):  
Douglas M. Templeton ◽  
Ying Liu
Keyword(s):  
Actin Cytoskeleton ◽  
Actin Polymerization ◽  
Mesangial Cells ◽  
Focal Adhesions ◽  
Filamentous Actin ◽  
Human Mesangial Cells ◽  
Dependent Protein

We provide an overview of our studies on cadmium and the actin cytoskeleton in mesangial cells, from earlier work on the effects of Cd2+ on actin polymerization in vivo and in vitro, to a role of disruption or stabilization of the cytoskeleton in apoptosis and apoptosis-like death. More recent studies implicate cadmium-dependent association of gelsolin and the Ca2+/calmodulin-dependent protein kinase II (CaMK-II) with actin filaments in cytoskeletal effects. We also present previously unpublished data concerning cadmium and the disruption of focal adhesions. The work encompasses studies on rat, mouse, and human mesangial cells. The major conclusions are that Cd2+ acts independently of direct effects on cellular Ca2+ levels to nevertheless activate Ca2+-dependent proteins that shift the actin polymerization–depolymerization in favour of depolymerization. Cadmium-dependent translocation of CaMK-IIδ, gelsolin, and a 50 kDa gelsolin cleavage fragment to the filamentous (F-)actin cytoskeleton appear to be involved. An intact filamentous actin cytoskeleton is required to initiate apoptotic and apoptotic-like death, but F-actin depolymerization is an eventual result.

Role of actin cytoskeleton in caerulein-induced intra-acinar cell activation of trypsinogen in an in vitro model of pancreatitis

2001 ◽  
Vol 120 (5) ◽  
pp. A336-A336
Author(s):  
L BHAGAT ◽  
A SALUJA ◽  
V SINGH ◽  
A SONG ◽  
G VANACKER ◽  
...  
Keyword(s):  
Actin Cytoskeleton ◽  
Acinar Cell ◽  
Cell Activation ◽  
In Vitro Model ◽  
Vitro Model

Role of actin cytoskeleton in caerulein-induced intra-acinar cell activation of trypsinogen in an in vitro model of pancreatitis

2001 ◽  
Vol 120 (5) ◽  
pp. A336
Author(s):  
Lakshmi Bhagat ◽  
Ashok K. Saluja ◽  
Vijay P. Singh ◽  
Albert M. Song ◽  
Gijs J. Van Acker ◽  
...  
Keyword(s):  
Actin Cytoskeleton ◽  
Acinar Cell ◽  
Cell Activation ◽  
In Vitro Model ◽  
Vitro Model

scholarly journals Drebrin Regulates Acetylcholine Receptor Clustering and Organization of Microtubules at the Postsynaptic Machinery

2021 ◽  
Vol 22 (17) ◽  
pp. 9387
Author(s):  
Paloma Alvarez-Suarez ◽  
Natalia Nowak ◽  
Anna Protasiuk-Filipunas ◽  
Hiroyuki Yamazaki ◽  
Tomasz J. Prószyński ◽  
...  
Keyword(s):  
Actin Cytoskeleton ◽  
Acetylcholine Receptors ◽  
Neuromuscular Junctions ◽  
Microtubule Network ◽  
Postsynaptic Protein ◽  
Cultured Myotubes ◽  
The Brain

Proper muscle function depends on the neuromuscular junctions (NMJs), which mature postnatally to complex “pretzel-like” structures, allowing for effective synaptic transmission. Postsynaptic acetylcholine receptors (AChRs) at NMJs are anchored in the actin cytoskeleton and clustered by the scaffold protein rapsyn, recruiting various actin-organizing proteins. Mechanisms driving the maturation of the postsynaptic machinery and regulating rapsyn interactions with the cytoskeleton are still poorly understood. Drebrin is an actin and microtubule cross-linker essential for the functioning of the synapses in the brain, but its role at NMJs remains elusive. We used immunohistochemistry, RNA interference, drebrin inhibitor 3,5-bis-trifluoromethyl pyrazole (BTP2) and co-immunopreciptation to explore the role of this protein at the postsynaptic machinery. We identify drebrin as a postsynaptic protein colocalizing with the AChRs both in vitro and in vivo. We also show that drebrin is enriched at synaptic podosomes. Downregulation of drebrin or blocking its interaction with actin in cultured myotubes impairs the organization of AChR clusters and the cluster-associated microtubule network. Finally, we demonstrate that drebrin interacts with rapsyn and a drebrin interactor, plus-end-tracking protein EB3. Our results reveal an interplay between drebrin and cluster-stabilizing machinery involving rapsyn, actin cytoskeleton, and microtubules.

scholarly journals Endothelial-specific Crif1 deletion induces BBB maturation and disruption via the alteration of actin dynamics by impaired mitochondrial respiration

2020 ◽  
Vol 40 (7) ◽  
pp. 1546-1561
Author(s):  
Min Joung Lee ◽  
Yunseon Jang ◽  
Jeongsu Han ◽  
Soo J Kim ◽  
Xianshu Ju ◽  
...  
Keyword(s):  
Actin Cytoskeleton ◽  
Motor Behavior ◽  
Actin Dynamics ◽  
Toxic Substances ◽  
Atp Production ◽  
Junctional Proteins ◽  
Peripheral Immune Cells

Cerebral endothelial cells (ECs) require junctional proteins to maintain blood–brain barrier (BBB) integrity, restricting toxic substances and controlling peripheral immune cells with a higher concentration of mitochondria than ECs of peripheral capillaries. The mechanism underlying BBB disruption by defective mitochondrial oxidative phosphorylation (OxPhos) is unclear in a mitochondria-related gene-targeted animal model. To assess the role of EC mitochondrial OxPhos function in the maintenance of the BBB, we developed an EC-specific CR6-interactin factor1 ( Crif1) deletion mouse. We clearly observed defects in motor behavior, uncompacted myelin and leukocyte infiltration caused by BBB maturation and disruption in this mice. Furthermore, we investigated the alteration in the actin cytoskeleton, which interacts with junctional proteins to support BBB integrity. Loss of Crif1 led to reorganization of the actin cytoskeleton and a decrease in tight junction-associated protein expression through an ATP production defect in vitro and in vivo. Based on these results, we suggest that mitochondrial OxPhos is important for the maturation and maintenance of BBB integrity by supplying ATP to cerebral ECs.

The role of silicon in forages: A quantitative X-Ray study

1987 ◽  
Vol 45 ◽  
pp. 416-417
Author(s):  
Janet H. Woodward ◽  
D. E. Akin
Keyword(s):  
Sodium Acetate ◽  
Dry Matter ◽  
Acetate Buffer ◽  
Plant Tissues ◽  
Sodium Acetate Buffer ◽  
X Ray ◽  
Dry Matter Digestibility ◽  
Percent Composition

Silicon (Si) is distributed throughout plant tissues, but its role in forages has not been clarified. Although Si has been suggested as an antiquality factor which limits the digestibility of structural carbohydrates, other research indicates that its presence in plants does not affect digestibility. We employed x-ray microanalysis to evaluate Si as an antiquality factor at specific sites of two cultivars of bermuda grass (Cynodon dactvlon (L.) Pers.). “Coastal” and “Tifton-78” were chosen for this study because previous work in our lab has shown that, although these two grasses are similar ultrastructurally, they differ in in vitro dry matter digestibility and in percent composition of Si.Two millimeter leaf sections of Tifton-7 8 (Tift-7 8) and Coastal (CBG) were incubated for 72 hr in 2.5% (w/v) cellulase in 0.05 M sodium acetate buffer, pH 5.0. For controls, sections were incubated in the sodium acetate buffer or were not treated.

Sign in / Sign up

Export Citation Format

Share Document