Protein phosphorylation: cellular functions and therapeutic perspectives

2001 ◽  
Vol 127 (12) ◽  
pp. 744-750 ◽  
Author(s):  
F. Marks
Keyword(s):  
Protein Phosphorylation ◽  
Cellular Functions

Hyperosmotic and isosmotic shrinkage differentially affect protein phosphorylation and ion transport

2012 ◽  
Vol 90 (2) ◽  
pp. 209-217 ◽  
Author(s):  
Svetlana V. Koltsova ◽  
Olga A. Akimova ◽  
Sergei V. Kotelevtsev ◽  
Ryszard Grygorczyk ◽  
Sergei N. Orlov
Keyword(s):  
Ion Transport ◽  
Protein Phosphorylation ◽  
Cell Volume ◽  
Mdck Cells ◽  
Rat Aorta ◽  
Cellular Functions ◽  
Hypertonic Medium ◽  
Mitogen Activated Protein ◽  
Volume Decrease ◽  
In Cells

In the present work, we compared the outcome of hyperosmotic and isosmotic shrinkage on ion transport and protein phosphorylation in C11-MDCK cells resembling intercalated cells from collecting ducts and in vascular smooth muscle cells (VSMC) from the rat aorta. Hyperosmotic shrinkage was triggered by cell exposure to hypertonic medium, whereas isosmotic shrinkage was evoked by cell transfer from an hypoosmotic to an isosmotic environment. Despite a similar cell volume decrease of 40%–50%, the consequences of hyperosmotic and isosmotic shrinkage on cellular functions were sharply different. In C11-MDCK and VSMC, hyperosmotic shrinkage completely inhibited Na+,K+-ATPase and Na+,Pi cotransport. In contrast, in both types of cells isosmotic shrinkage slightly increased rather than suppressed Na+,K+-ATPase and did not change Na+,Pi cotransport. In C11-MDCK cells, phosphorylation of JNK1/2 and Erk1/2 mitogen-activated protein kinases was augmented in hyperosmotically shrunken cells by ∼7- and 2-fold, respectively, but was not affected in cells subjected to isosmotic shrinkage. These results demonstrate that the data obtained in cells subjected to hyperosmotic shrinkage cannot be considered as sufficient proof implicating cell volume perturbations in the regulation of cellular functions under isosmotic conditions.

scholarly journals The complex interplay in the regulation of cardiac pathophysiologic functionalities by protein kinases and phosphatases

2021 ◽  
Vol 6 (3) ◽  
pp. 048-054
Author(s):  
Chukwuma Sr Chrysanthus
Keyword(s):  
Heart Failure ◽  
Protein Phosphorylation ◽  
Cardiovascular System ◽  
Protein Kinases ◽  
Cell Fate ◽  
Body Burden ◽  
The Body ◽  
Discrete Control ◽  
Cellular Functions ◽  
Cardiac Excitation

Protein phosphorylation regulates several dimensions of cell fate and is substantially dysregulated in pathophysiological instances as evident spatiotemporally via intracellular localizations or compartmentalizations with discrete control by specific kinases and phosphatases. Cardiovascular disease manifests as an intricately complex entity presenting as a derangement of the cardiovascular system. Cardiac or heart failure connotes the pathophysiological state in which deficient cardiac output compromises the body burden and requirements. Protein kinases regulate several pathophysiological processes and are emerging targets for drug lead or discovery. The protein kinases are family members of the serine/threonine phosphatases. Protein kinases covalently modify proteins by attaching phosphate groups from ATP to residues of serine, threonine and/or tyrosine. Protein kinases and phosphatases are pivotal in the regulatory mechanisms in the reversible phosphorylation of diverse effectors whereby discrete signaling molecules regulate cardiac excitation and contraction. Protein phosphorylation is critical for the sustenance of cardiac functionalities. The two major contributory ingredients to progressive myocardium derangement are dysregulation of Ca2+ processes and contemporaneous elevated concentrations of reactive oxygen species, ROS. Certain cardiac abnormalities include cardiac myopathy or hypertrophy due to response in untoward haemodynamic demand with concomitant progressive heart failure. The homeostasis or equilibrium between protein kinases and phosphatases influence cardiac morphology and excitability during pathological and physiological processes of the cardiovascular system. Inasmuch as protein kinases regulate numerous dimensions of normal cellular functions, the pathophysiological dysfunctionality of protein kinase signaling pathways undergirds the molecular aspects of several cardiovascular diseases or disorders as related in this study. These have presented protein kinases as essential and potential targets for drug discovery and heart disease therapy.

Surface Structure of Nucleated Animal Cells: Carbon Replicas

1967 ◽  
Vol 25 ◽  
pp. 120-121
Author(s):  
Robert M. Glaeser ◽  
Thea B. Scott
Keyword(s):  
Cell Surface ◽  
Surface Structure ◽  
Particle Diameter ◽  
Cellular Functions ◽  
Animal Cells ◽  
Replica Technique ◽  
Carbon Replica ◽  
Characteristic Particle ◽  
Cell Surface Structure ◽  
Carbon Replicas

The carbon-replica technique can be used to obtain information about cell-surface structure that cannot ordinarily be obtained by thin-section techniques. Mammalian erythrocytes have been studied by the replica technique and they appear to be characterized by a pebbly or “plaqued“ surface texture. The characteristic “particle” diameter is about 200 Å to 400 Å. We have now extended our observations on cell-surface structure to chicken and frog erythrocytes, which possess a broad range of cellular functions, and to normal rat lymphocytes and mouse ascites tumor cells, which are capable of cell division. In these experiments fresh cells were washed in Eagle's Minimum Essential Medium Salt Solution (for suspension cultures) and one volume of a 10% cell suspension was added to one volume of 2% OsO4 or 5% gluteraldehyde in 0.067 M phosphate buffer, pH 7.3. Carbon replicas were obtained by a technique similar to that employed by Glaeser et al. Figure 1 shows an electron micrograph of a carbon replica made from a chicken erythrocyte, and Figure 2 shows an enlarged portion of the same cell.

Multimode light microscopy and fluorescence-based reagents as tools for the study of chemical and molecular dynamics of living cells and tissues

1992 ◽  
Vol 50 (1) ◽  
pp. 418-419
Author(s):  
D. L. Taylor
Keyword(s):  
Living Cells ◽  
Cellular Level ◽  
Molecular Techniques ◽  
Cellular Functions ◽  
Macromolecular Assemblies ◽  
Cell Functions ◽  
Molecular Events ◽  
Yield Information ◽  
Full Knowledge ◽  
Structural Methods

Cells function through the complex temporal and spatial interplay of ions, metabolites, macromolecules and macromolecular assemblies. Biochemical approaches allow the investigator to define the components and the solution chemical reactions that might be involved in cellular functions. Static structural methods can yield information concerning the 2- and 3-D organization of known and unknown cellular constituents. Genetic and molecular techniques are powerful approaches that can alter specific functions through the manipulation of gene products and thus identify necessary components and sequences of molecular events. However, full knowledge of the mechanism of particular cell functions will require direct measurement of the interplay of cellular constituents. Therefore, there has been a need to develop methods that can yield chemical and molecular information in time and space in living cells, while allowing the integration of information from biochemical, molecular and genetic approaches at the cellular level.

Correlation Between Cellular Functions and Morphological Changes of Human Trophoblast in Vitro

1975 ◽  
Vol 33 ◽  
pp. 600-601
Author(s):  
John C. Garancis ◽  
Robert O. Hussa ◽  
Michael T. Story ◽  
Donald Yorde ◽  
Roland A. Pattillo
Keyword(s):  
Electron Microscopy ◽  
Cellular Proliferation ◽  
Morphological Changes ◽  
Culture Fluid ◽  
Cellular Functions ◽  
Human Trophoblast ◽  
Transmission Electron ◽  
Marked Activity ◽  
Malignant Trophoblast

Human malignant trophoblast cells in continuous culture were incubated for 3 days in medium containing 1 mM N6-O2'-dibutyryl cyclic adenosine 3':5'-monophosphate (dibutyryl cyclic AMP) and 1 mM theophylline. The culture fluid was replenished daily. Stimulated cultures secreted many times more chorionic gonadotropin and estrogens than did control cultures in the absence of increased cellular proliferation. Scanning electron microscopy revealed remarkable surface changes of stimulated cells. Control cells (not stimulated) were smooth or provided with varying numbers of microvilli (Fig. 1). The latter, usually, were short and thin. The surface features of stimulated cells were considerably different. There was marked increase of microvilli which appeared elongated and thick. Many cells were covered with confluent polypoid projections (Fig. 2). Transmission electron microscopy demonstrated marked activity of cytoplasmic organelles. Mitochondria were increased in number and size; some giant forms with numerous cristae were observed.

Signal-regulated oxidation of proteins via MICAL

2020 ◽  
Vol 48 (2) ◽  
pp. 613-620
Author(s):  
Clara Ortegón Salas ◽  
Katharina Schneider ◽  
Christopher Horst Lillig ◽  
Manuela Gellert
Keyword(s):  
Signal Transduction ◽  
Hydrogen Peroxide ◽  
Cell Death ◽  
Redox Regulation ◽  
Signal Transduction Pathways ◽  
Cellular Functions ◽  
Intracellular Signals ◽  
Amino Acid Side Chains ◽  
Specific Receptors ◽  
Sulfur Containing

Processing of and responding to various signals is an essential cellular function that influences survival, homeostasis, development, and cell death. Extra- or intracellular signals are perceived via specific receptors and transduced in a particular signalling pathway that results in a precise response. Reversible post-translational redox modifications of cysteinyl and methionyl residues have been characterised in countless signal transduction pathways. Due to the low reactivity of most sulfur-containing amino acid side chains with hydrogen peroxide, for instance, and also to ensure specificity, redox signalling requires catalysis, just like phosphorylation signalling requires kinases and phosphatases. While reducing enzymes of both cysteinyl- and methionyl-derivates have been characterised in great detail before, the discovery and characterisation of MICAL proteins evinced the first examples of specific oxidases in signal transduction. This article provides an overview of the functions of MICAL proteins in the redox regulation of cellular functions.

Involvement of protein phosphorylation in the sensitivity of photosystem II to strong illumination

1994 ◽  
Vol 92 (1) ◽  
pp. 181-187
Author(s):  
Maria T. Giardi ◽  
Josef Komenda ◽  
Jiri Masojidek
Keyword(s):  
Photosystem Ii ◽  
Protein Phosphorylation

Receptor Mediated Binding of the Fibrinolytic Components, Plasminogen and Urokinase, to Peripheral Blood Cells

1987 ◽  
Vol 58 (03) ◽  
pp. 936-942 ◽  
Author(s):  
Lindsey A Miles ◽  
Edward F Plow
Keyword(s):  
T Cells ◽  
B Cell ◽  
Peripheral Blood ◽  
Binding Sites ◽  
Blood Cells ◽  
High Capacity ◽  
Red Cells ◽  
Peripheral Blood Cells ◽  
Cellular Functions ◽  
Fibrinolytic Proteins

SummaryGlu-plasminogen binds to platelets; the monocytoid line, U937, and the human fetal fibroblast line, GM1380 bind both plasminogen and its activator, urokinase. This study assesses the interaction of these fibrinolytic proteins with circulating human blood cells. Plasminogen bound minimally to red cells but bound saturably and reversibly to monocytes, granulocytes and lymphocytes with apparent Kd values of 0.9-1.4 μM. The interactions were of high capacity with 1.6 to 49 × 105 sites/cell and involved the lysine binding sites of plasminogen. Both T cells and non-rosetting lymphocytes and two B cell lines saturably bound plasminogen. Urokinase bound saturably to gianulocytes, monocytes, non-rosetting lymphocytes and a B cell line, but minimally to T cells, platelets and red cells. Therefore, plasminogen binding sites of high capacity, of similar affinities, and with common recognition specificities are expressed by many peripheral blood cells. Urokinase receptors are also widely distributed, but less so than plasminogen binding sites. The binding ol plasminogen and/ or urokinase to these cells may lead to generation of cell- associated proteolytic activity which contributes to a variety of cellular functions.

TSH receptor-dependent cellular functions measured with the thyroid cell strain FRTL-5

1989 ◽  
Vol 120 (3_Suppl) ◽  
pp. S194
Author(s):  
B. E. WENZEL ◽  
A. HEUFELDER ◽  
T. MACKENROTH ◽  
P. C. SCRIBA
Keyword(s):  
Cell Strain ◽  
Tsh Receptor ◽  
Thyroid Cell ◽  
Cellular Functions
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