Changing of expression actinbinding proteins in the kidney under dehydration

Actin is related to main structural proteins in eukaryotes. In opposite to muscle alpha-actin, beta-actin is expressing in all types of cells. The constant reorganization of actin cytoskeleton takes place in non-muscle cells. Fibrillar actin, organized by globular monomers, interacts with the actin-binding proteins. Alpha-actinin forms a transverse links in actin fibrillar network, as well as concentrates in the fields of focal contacts. Tropomyosin is related to regulatory components of beta-actin, and due to the expense of longitudinal localization of the molecule in the groove of actin microfilament, stereochemically shields the sites of other actin-binding proteins. The most important function of actin cytoskeleton is the participation in the transportation of vesicles with aquaporins of second type in principal cells of an epithelium of collecting ducts in renal medulla. Vasopressin is stimulating the release of aquaporin tetramers from cytoplasmic store to apical plasmatic membrane. The participation and role of separate cytoskeleton proteins in the process of aquaporin trafficking and forming additional pores for water stays a poorly studied place in the molecular physiology of kidney. We explored the osmoregulatory action of prolonged hydration and dehydration on the protein composition of actin cytoskeleton in rats depending on the presence or absence of the actively expressing vasopressin gene in the genome. We found that the efficiency of the renal concentrating system, controlled by vasopressin, depends on expression of actin-binding proteins in the renal medulla. On the background of a stable level of inner cellular beta-actin, a change of expression an alpha-actinin and tropomyosin is observed. Dehydration of the organism is accompanied by essential reducing of alpha-actinin. In the absence of vasopressin, reduction of alpha-actinin has a smaller amplitude. The presence of the normal vasopressin gene in the genome, regardless of transitory expression level and secretion of hormone, is a factor of lower tropomyosin in the kidney. The most probable molecular mechanism of changing the expression of the genes for alpha-actinin and tropomyosin is transduction of the V2-mediated vasopressin hormonal signal to protein kinase A, phosphorylation of the cAMPresponsible transcriptional factor CREB, and nuclear CREB interaction with gene CRE sites sensitive to it.

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Ultrastructure of the yeast actin cytoskeleton and its association with the plasma membrane.

The Journal of Cell Biology ◽

10.1083/jcb.125.2.381 ◽

1994 ◽

Vol 125 (2) ◽

pp. 381-391 ◽

Cited By ~ 245

Author(s):

J Mulholland ◽

D Preuss ◽

A Moon ◽

A Wong ◽

D Drubin ◽

...

Keyword(s):

Plasma Membrane ◽

Actin Cytoskeleton ◽

Binding Proteins ◽

Ultrastructural Level ◽

Actin Binding ◽

Cortical Actin ◽

Actin Binding Proteins ◽

Double Labeling ◽

Wall Growth ◽

Cortical Cytoskeleton

We characterized the yeast actin cytoskeleton at the ultrastructural level using immunoelectron microscopy. Anti-actin antibodies primarily labeled dense, patchlike cortical structures and cytoplasmic cables. This localization recapitulates results obtained with immunofluorescence light microscopy, but at much higher resolution. Immuno-EM double-labeling experiments were conducted with antibodies to actin together with antibodies to the actin binding proteins Abp1p and cofilin. As expected from immunofluorescence experiments, Abp1p, cofilin, and actin colocalized in immuno-EM to the dense patchlike structures but not to the cables. In this way, we can unambiguously identify the patches as the cortical actin cytoskeleton. The cortical actin patches were observed to be associated with the cell surface via an invagination of plasma membrane. This novel cortical cytoskeleton-plasma membrane interface appears to consist of a fingerlike invagination of plasma membrane around which actin filaments and actin binding proteins are organized. We propose a possible role for this unique cortical structure in wall growth and osmotic regulation.

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STIP1/HOP Regulates the Actin Cytoskeleton through Interactions with Actin and Changes in Actin-Binding Proteins Cofilin and Profilin

International Journal of Molecular Sciences ◽

10.3390/ijms21093152 ◽

2020 ◽

Vol 21 (9) ◽

pp. 3152 ◽

Cited By ~ 1

Author(s):

Samantha Joy Beckley ◽

Morgan Campbell Hunter ◽

Sarah Naulikha Kituyi ◽

Ianthe Wingate ◽

Abantika Chakraborty ◽

...

Keyword(s):

Actin Cytoskeleton ◽

Binding Proteins ◽

Major Effect ◽

Vital Role ◽

Actin Dynamics ◽

Actin Binding ◽

Nuclear Accumulation ◽

Actin Binding Proteins ◽

Hsp90 Chaperone

Cell migration plays a vital role in both health and disease. It is driven by reorganization of the actin cytoskeleton, which is regulated by actin-binding proteins cofilin and profilin. Stress-inducible phosphoprotein 1 (STIP1) is a well-described co-chaperone of the Hsp90 chaperone system, and our findings identify a potential regulatory role of STIP1 in actin dynamics. We show that STIP1 can be isolated in complex with actin and Hsp90 from HEK293T cells and directly interacts with actin in vitro via the C-terminal TPR2AB-DP2 domain of STIP1, potentially due to a region spanning two putative actin-binding motifs. We found that STIP1 could stimulate the in vitro ATPase activity of actin, suggesting a potential role in the modulation of F-actin formation. Interestingly, while STIP1 depletion in HEK293T cells had no major effect on total actin levels, it led to increased nuclear accumulation of actin, disorganization of F-actin structures, and an increase and decrease in cofilin and profilin levels, respectively. This study suggests that STIP1 regulates the cytoskeleton by interacting with actin, or via regulating the ratio of proteins known to affect actin dynamics.

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CRMP-2 Is Involved in Kinesin-1-Dependent Transport of the Sra-1/WAVE1 Complex and Axon Formation

Molecular and Cellular Biology ◽

10.1128/mcb.25.22.9920-9935.2005 ◽

2005 ◽

Vol 25 (22) ◽

pp. 9920-9935 ◽

Cited By ~ 166

Author(s):

Yoji Kawano ◽

Takeshi Yoshimura ◽

Daisuke Tsuboi ◽

Saeko Kawabata ◽

Takako Kaneko-Kawano ◽

...

Keyword(s):

Actin Cytoskeleton ◽

Hippocampal Neurons ◽

Binding Proteins ◽

Neuronal Development ◽

Critical Role ◽

Growth Cones ◽

Axon Outgrowth ◽

Actin Binding ◽

Dependent Manner ◽

Actin Binding Proteins

ABSTRACT A neuron has two types of highly polarized cell processes, the single axon and multiple dendrites. One of the fundamental questions of neurobiology is how neurons acquire such specific and polarized morphologies. During neuronal development, various actin-binding proteins regulate dynamics of actin cytoskeleton in the growth cones of developing axons. The regulation of actin cytoskeleton in the growth cones is thought to be involved in axon outgrowth and axon-dendrite specification. However, it is largely unknown which actin-binding proteins are involved in axon-dendrite specification and how they are transported into the developing axons. We have previously reported that collapsin response mediator protein 2 (CRMP-2) plays a critical role in axon outgrowth and axon-dendrite specification (N. Inagaki, K. Chihara, N. Arimura, C. Menager, Y. Kawano, N. Matsuo, T. Nishimura, M. Amano, and K. Kaibuchi, Nat. Neurosci. 4:781-782, 2001). Here, we found that CRMP-2 interacted with the specifically Rac1-associated protein 1 (Sra-1)/WASP family verprolin-homologous protein 1 (WAVE1) complex, which is a regulator of actin cytoskeleton. The knockdown of Sra-1 and WAVE1 by RNA interference canceled CRMP-2-induced axon outgrowth and multiple-axon formation in cultured hippocampal neurons. We also found that CRMP-2 interacted with the light chain of kinesin-1 and linked kinesin-1 to the Sra-1/WAVE1 complex. The knockdown of CRMP-2 and kinesin-1 delocalized Sra-1 and WAVE1 from the growth cones of axons. These results suggest that CRMP-2 transports the Sra-1/WAVE1 complex to axons in a kinesin-1-dependent manner and thereby regulates axon outgrowth and formation.

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16-P005 Mutations in the lethal ciliopathy Meckel–Gruber syndrome alter the subcellular distribution of actin-binding proteins and disrupt the actin cytoskeleton

Mechanisms of Development ◽

10.1016/j.mod.2009.06.696 ◽

2009 ◽

Vol 126 ◽

pp. S263

Author(s):

Matthew Adams ◽

Helen Dawe ◽

Gabrielle Wheway ◽

Katarzyna Szymanska ◽

Clare Logan ◽

...

Keyword(s):

Actin Cytoskeleton ◽

Subcellular Distribution ◽

Binding Proteins ◽

Actin Binding ◽

Actin Binding Proteins

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Actin-binding proteins: the long road to understanding the dynamic landscape of cellular actin networks

Molecular Biology of the Cell ◽

10.1091/mbc.e15-10-0728 ◽

2016 ◽

Vol 27 (16) ◽

pp. 2519-2522 ◽

Cited By ~ 21

Author(s):

Pekka Lappalainen

Keyword(s):

Actin Cytoskeleton ◽

Actin Filaments ◽

Binding Proteins ◽

Three Dimensional ◽

Actin Dynamics ◽

Actin Binding ◽

Actin Binding Proteins ◽

Vast Number ◽

Actin Regulatory Proteins ◽

The Individual

The actin cytoskeleton supports a vast number of cellular processes in nonmuscle cells. It is well established that the organization and dynamics of the actin cytoskeleton are controlled by a large array of actin-binding proteins. However, it was only 40 years ago that the first nonmuscle actin-binding protein, filamin, was identified and characterized. Filamin was shown to bind and cross-link actin filaments into higher-order structures and contribute to phagocytosis in macrophages. Subsequently many other nonmuscle actin-binding proteins were identified and characterized. These proteins regulate almost all steps of the actin filament assembly and disassembly cycles, as well as the arrangement of actin filaments into diverse three-dimensional structures. Although the individual biochemical activities of most actin-regulatory proteins are relatively well understood, knowledge of how these proteins function together in a common cytoplasm to control actin dynamics and architecture is only beginning to emerge. Furthermore, understanding how signaling pathways and mechanical cues control the activities of various actin-binding proteins in different cellular, developmental, and pathological processes will keep researchers busy for decades.

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The role of actin-binding proteins in the control of endothelial barrier integrity

Thrombosis and Haemostasis ◽

10.1160/th14-04-0298 ◽

2015 ◽

Vol 113 (01) ◽

pp. 20-36 ◽

Cited By ~ 65

Author(s):

Alexander García-Ponce ◽

Alí Francisco Citalán-Madrid ◽

Martha Velázquez-Avila ◽

Hilda Vargas-Robles ◽

Michael Schnoor

Keyword(s):

Endothelial Cell ◽

Actin Cytoskeleton ◽

Vascular Permeability ◽

Binding Proteins ◽

Small Gtpases ◽

Endothelial Barrier ◽

Actin Binding ◽

Actin Binding Proteins ◽

Cell Contacts

SummaryThe endothelial barrier of the vasculature is of utmost importance for separating the blood stream from underlying tissues. This barrier is formed by tight and adherens junctions (TJ and AJ) that form intercellular endothelial contacts. TJ and AJ are integral membrane structures that are connected to the actin cytoskeleton via various adaptor molecules. Consequently, the actin cytoskeleton plays a crucial role in regulating the stability of endothelial cell contacts and vascular permeability. While a circumferential cortical actin ring stabilises junctions, the formation of contractile stress fibres, e. g. under inflammatory conditions, can contribute to junction destabilisation. However, the role of actin-binding proteins (ABP) in the control of vascular permeability has long been underestimated. Naturally, ABP regulate permeability via regulation of actin remodelling but some actin-binding molecules can also act independently of actin and control vascular permeability via various signalling mechanisms such as activation of small GTPases. Several studies have recently been published highlighting the importance of actin-binding molecules such as cortactin, ezrin/ radixin/moesin, Arp2/3, VASP or WASP for the control of vascular permeability by various mechanisms. These proteins have been described to regulate vascular permeability under various pathophysiological conditions and are thus of clinical relevance as targets for the development of treatment strategies for disorders that are characterised by vascular hyperpermeability such as sepsis. This review highlights recent advances in determining the role of ABP in the control of endothelial cell contacts and vascular permeability.

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Biomechanical analysis of actin cytoskeleton function based on a spring network cell model

Proceedings of the Institution of Mechanical Engineers Part C Journal of Mechanical Engineering Science ◽

10.1177/0954406216668546 ◽

2016 ◽

Vol 231 (7) ◽

pp. 1308-1323 ◽

Cited By ~ 5

Author(s):

Hamed Ghaffari ◽

Mohammad Said Saidi ◽

Bahar Firoozabadi

Keyword(s):

Actin Cytoskeleton ◽

Actin Filaments ◽

Cell Shape ◽

Binding Proteins ◽

Cell Model ◽

Shape Change ◽

Cell Deformation ◽

Actin Binding ◽

Actin Binding Proteins ◽

Cell Shape Change

In this study, a new method for the simulation of the time-dependent behavior of actin cytoskeleton during cell shape change is proposed. For this purpose, a three-dimensional model of endothelial cell consisting of cell membrane, nucleus membrane, and main components of cytoskeleton, namely actin filaments, microtubules, and intermediate filaments is utilized. Actin binding proteins, which play a key role in regulating actin cytoskeleton behavior, are also simulated by using a novel technique. The actin cytoskeleton in this model is more dynamic and adoptable during cell deformation in comparison to previous models. The proposed model is subjected to compressive force between parallel micro plates in order to investigate actin cytoskeleton role in cell stiffening behavior, nucleus deformation, and cell shape change. The validity of the model is examined through the comparison of the obtained results with the data presented in previous literature. Not only does the model force deformation curve lie within a range of the experimental data, but also the elastic modulus of the cell model is in accordance with former studies. Our findings demonstrate that augmentation of actin filaments concentration within the cell reduces force transmission from cell membrane to the nucleus. Furthermore, actin binding proteins concentration increases by the enhancement of cell deformation and it is also indicated that cell stiffening with an increase in applied force is significantly affected by actin filaments reorientation, actin binding proteins reorganization and actin binding proteins augmentation.

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