scholarly journals Autophosphorylation kinetics of protein kinases

2002 ◽  
Vol 368 (3) ◽  
pp. 947-952 ◽  
Author(s):  
Zhi-Xin WANG ◽  
Jia-Wei WU
Keyword(s):  
Signal Transduction ◽  
Protein Kinases ◽  
Human Placenta ◽  
Kinetic Equations ◽  
Turnover Number ◽  
Cellular Signal ◽  
Membrane Bound ◽  
Almost All ◽  
Kinetics Of ◽  
Menten Constant

Protein kinases play a central role in cellular signal transduction, by transmitting biochemical information between activated membrane-bound receptors and physiological target proteins. In addition to phosphorylating other proteins, almost all protein kinases catalyse autophosphorylation reactions (i.e. reactions in which the kinase serves as its own substrate). The autophosphorylation reactions can be intramolecular or intermolecular. In the present study, a detailed kinetic analysis of the intermolecular autophosphorylation reaction is presented. On the basis of the kinetic equations, a new procedure is developed to evaluate the kinetic parameters of the autophosphorylation reaction. This method was used to analyse the intermolecular autophosphorylation of an S6/H4 kinase from human placenta. At a fixed ATP concentration of 0.125mM, the apparent catalytic-centre activity (turnover number; kcat) and apparent Michaelis—Menten constant (Km) for the autophosphorylation reaction were determined to be 0.91min-1 and 0.86μM respectively.

EXTRAOCULAR CELLULAR PHOTOTRANSDUCTION

2009 ◽  
Vol 02 (01) ◽  
pp. 93-100 ◽  
Author(s):  
LING ZHU ◽  
TIMON CHENG-YI LIU ◽  
MIN WU ◽  
JIAN-QIN YUAN ◽  
TONG-SHENG CHEN
Keyword(s):  
Signal Transduction ◽  
Protein Kinase ◽  
Monochromatic Light ◽  
Mitogen Activated Protein Kinase ◽  
Signal Transduction Pathways ◽  
Mitogen Activated Protein ◽  
Cellular Signal ◽  
Gs Protein ◽  
Almost All ◽  
Relationship Of

Photobiomodulation (PBM) is a modulation of monochromatic light or laser irradiation (LI) on biosystems. It is reviewed from the viewpoint of extraocular phototransduction in this paper. It was found that LI can induce extraocular phototransduction, and there may be an exact correspondence relationship of LI at different wavelengths and in different dose zones, and cellular signal transduction pathways. The signal transduction pathways can be classified into two types so that the Gs protein-mediated pathways belong to pathway 1, and the other pathways such as protein kinase Cs -mediated pathways and mitogen-activated protein kinase-mediated pathways belong to pathway 2. Almost all the present pathways found to mediate PBM belong to pathway 2, but there should be a pathway 1-mediated PBM. The previous studies were rather preliminary, and therefore further work should be done.

Postal code for a plant MAPK

2012 ◽  
Vol 446 (2) ◽  
pp. e5-e7 ◽  
Author(s):  
Brian E. Ellis
Keyword(s):  
Signal Transduction ◽  
Protein Kinase ◽  
Protein Kinases ◽  
Mitogen Activated Protein Kinase ◽  
Postal Code ◽  
Biochemical Journal ◽  
Mitogen Activated Protein ◽  
Cellular Signal ◽  
Efficient Route ◽  
Kinase Substrates

Plants contain hundreds of protein kinases that are believed to provide cellular signal transduction services, but the identities of the proteins they are targeting are largely unknown. Using an Arabidopsis MAPK (mitogen-activated protein kinase) (MPK6) as a model, Sörensson et al. describe in this issue of the Biochemical Journal how arrayed combinatorial peptide scanning offers an efficient route to discovery of new potential kinase substrates.

Mechanisms of autoantibody-mediated thrombosis

Lupus ◽  
1998 ◽  
Vol 7 (2_suppl) ◽  
pp. 114-119 ◽  
Author(s):  
R.A.S. Roubey
Keyword(s):  
Signal Transduction ◽  
Cell Surface ◽  
Plasma Proteins ◽  
Cross Linking ◽  
Prothrombotic State ◽  
Cellular Activation ◽  
Surface Receptors ◽  
Glycoprotein I ◽  
Membrane Bound ◽  
Kinetics Of

It is widely hypothesized that autoantibodies directly contribute to the prothrombotic state in the antiphospholipid syndrome (APS). The discovery that antiphospholipid autoantibodies are specific for phospholipid-binding plasma proteins (β2-glycoprotein I, prothrombin, etc.) has allowed a much more precise investigation of the interactions of autoantibodies and antigens, and the effects of these interaction on hemostastis. Recent studies suggest that two types of interactions may be important in the pathophysiology of APS: (1) antibody cross-linking of membrane bound antigens may alter the kinetics of phospholipid-dependent reactions; and (2) antibody cross-linking of antigens bound to cell surface receptors may trigger signal transduction and cellular activation. In light of these findings, previous reports implicating various mechanisms of autoantibody-mediated thrombosis are being re-evaluated.

Growth hormone induces expression of c-jun and jun B oncogenes and employs a protein kinase C signal transduction pathway for the induction of c-fos oncogene expression

1991 ◽  
Vol 6 (2) ◽  
pp. 179-188 ◽  
Author(s):  
M. C. Slootweg ◽  
R. P. de Groot ◽  
M. P. M. Herrmann-Erlee ◽  
I. Koornneef ◽  
W. Kruijer ◽  
...  
Keyword(s):  
Signal Transduction ◽  
Protein Kinase C ◽  
Protein Kinase ◽  
Protein Kinases ◽  
Early Gene ◽  
Induced Expression ◽  
Oncogene Expression ◽  
Kinase C ◽  
Cellular Signal ◽  
Jun B

ABSTRACT Although the structure of several members of the GH receptor family has been defined, signal transduction following GH binding to its receptor has not been elucidated. Mouse osteoblasts were used to study the effect of GH on immediate early gene expression and, subsequently, the cellular signal(s) mediating this expression were analysed. GH rapidly and transiently induced the expression of c-jun and jun B in concert with the already reported expression of c-fos. The GH-induced expression of c-fos was completely blocked by the protein kinase inhibitors staurosporine and H7, indicating that the action of GH is mediated by one or several protein kinases. We next analysed the identity of the putative protein kinases in more detail by using a more specific protein kinase inhibitor, namely the ether-lipid 1-O-alkyl-2-O-methylglycerol, understood to be an inhibitor of protein kinase C (PKC). Data obtained from these studies revealed that GH-induced expression of c-fos is mediated by PKC. In addition, we observed a profound increase in formation of the PKC activator diacyglycerol upon addition of GH, a natural activator of PKC. In conclusion, upon binding of GH to mouse osteoblasts, the receptor-mediated cellular signal involves diacyglycerol formation and activation of PKC, leading to the induction of oncogene expression. Finally, the expression of c-fos, c-jun and jun B results in an increased binding of protein complexes to AP-1 binding sites.

Polyamines: New Cues in Cellular Signal Transduction

Physiology ◽  
2001 ◽  
Vol 16 (3) ◽  
pp. 106-109 ◽  
Author(s):  
Uriel Bachrach ◽  
Yong-Chun Wang ◽  
Amalia Tabib
Keyword(s):  
Signal Transduction ◽  
Protein Kinases ◽  
Tyrosine Kinases ◽  
Map Kinases ◽  
Cultured Cells ◽  
Polyamine Biosynthesis ◽  
Cellular Signal Transduction ◽  
Naturally Occurring ◽  
Cellular Signal

The naturally occurring polyamines putrescine, spermidine, and spermine are involved in signal transduction. This has been demonstrated by using inhibitors for polyamine biosynthesis (such as α-difluoromethylornithine) or adding polyamines to cultured cells. Different polyamines, preferentially activated protein kinases (tyrosine kinases and MAP kinases), stimulated the expression of nuclear protooncogenes (myc, jun, and fos).

The Kinetics of Glucose Decomposition with Sulfate Reduction in the Anaerobic Fluidized Bed Reactor

1993 ◽  
Vol 28 (2) ◽  
pp. 135-144 ◽  
Author(s):  
S. Matsui ◽  
R. Ikemoto Yamamoto ◽  
Y. Tsuchiya ◽  
B. Inanc
Keyword(s):  
Sulfate Reduction ◽  
Fluidized Bed ◽  
Kinetic Equations ◽  
Fluidized Bed Reactor ◽  
Order Reaction ◽  
First Order Reaction ◽  
First Order ◽  
Glucose Decomposition ◽  
Reaction Equations ◽  
Kinetics Of

Using a fluidized bed reactor, experiments on glucose decomposition with and without sulfate reduction were conducted. Glucose in the reactor was mainly decomposed into lactate and ethanol. Lactate was mainly decomposed into propionate and acetate, while ethanol was decomposed into propionate, acetate, and hydrogen. Sulfate reduction was not involved in the decomposition of glucose, lactate, and ethanol, but was related to propionate and acetate decomposition. The stepwise reactions were modeled using either a Monod expression or first order reaction kinetics in respect to the reactions. The coefficients of the kinetic equations were determined experimentally. The modified Monod and first order reaction equations were effective at predicting concentrations of glucose, lactate, ethanol, propionate, acetate, and sulfate along the beight of the reactor. With sulfate reduction, propionate was decomposed into acetate, while without sulfate reduction, accumulation of propionate was observed in the reactor. Sulfate reduction accelerated propionate conversion into acetate by decreasing the hydrogen concentration.

Kinetics of the catalytic hydrodesulphurization reaction system; hydrogenolysis of thiophene

1980 ◽  
Vol 45 (10) ◽  
pp. 2728-2741 ◽  
Author(s):  
Pavel Fott ◽  
Petr Schneider
Keyword(s):  
Atmospheric Pressure ◽  
Active Sites ◽  
Flow Reactor ◽  
Kinetic Equations ◽  
Reaction System ◽  
Reaction Products ◽  
Molybdenum Catalyst ◽  
Cobalt Molybdenum Catalyst ◽  
Kinetics Of ◽  
Reaction Schemes

Kinetics have been studied of the reaction system taking place during the reaction of thiophene on the cobalt-molybdenum catalyst in a gradientless circulation flow reactor at 360 °C and atmospheric pressure. Butane has been found present in a small amount in the reaction products even at very low conversion. In view of this, consecutive and parallel-consecutive (triangular) reaction schemes have been proposed. In the former scheme the appearance of butane is accounted for by rate of desorption of butene being comparable with the rate of its hydrogenation. According to the latter scheme part of the butane originates from thiophene via a different route than through hydrogenation of butene. Analysis of the kinetic data has revealed that the reaction of thiophene should be considered to take place on other active sites than that of butene. Kinetic equations derived on this assumption for the consecutive and the triangular reaction schemes correlate experimental data with acceptable accuracy.

Sign in / Sign up

Export Citation Format

Share Document