Calmodulin

An immuno-homologue of maize Ca2+/calmodulin (CaM)dependent protein kinase with a molecular mass of 72 kDa was identified in pea. The pea kinase (PsCCaMK) was upregulated in roots in response to low temperature and increased salinity. Exogenous Ca2+ application increased the kinase level and the response was faster than that obtained following stress application. Low temperaturemediated, but not salinity-mediated stress kinase increase was inhibited by the application of EGTA and W7, a CaM inhibitor....

12p system191 01-06-2013 40 5   Download

Calmodulin (CaM) is phosphorylated in vitro and in vivo by multiple protein-serine/threonine and protein-tyrosine kinases. Casein kinase II and myosin light-chain kinase are two of the well established protein-serine/threonine kinases implicated in this process. On the other hand, within the protein-tyrosine kinases involved in the phosphorylation of CaM are receptors with tyrosine kinase activity, such as the insulin receptor and the epidermal growth factor receptor, and nonreceptor protein-tyrosine kinases, such as several members of the Src family kinases, Janus kinase 2, and p38Syk....

13p research12 01-06-2013 51 6   Download

Chimeric calcium/calmodulin dependent protein kinase (CCaMK) is characterized by the presence of a visinin-like Ca 2+ -binding domain unlike other known calmodulin-dependent kinases. Ca 2+ -Binding to the visinin-like domain leads to autophosphorylation and changes in the affinity for calmodulin [Sathyanarayanan P.V., Cremo C.R. & Poovaiah B.W. (2000)J. Biol. Chem. 275, 30417–30422]. Here, we report that the Ca 2+ -stimulated autophosphory-lation of CCaMK results in time-dependent loss of enzyme activity. ...

7p research12 29-04-2013 36 3   Download

In human neutrophils, both changes in intracellular Ca 2+ concentrations, [Ca 2+ ] i , and activation of phosphatidyl-inositol-3 kinase (PtdIns3K) have been proposed to play a role in regulating cellular function induced by chemoattr-actants. In this studywe have investigated the role of [Ca 2+ ] i and its effector molecule calmodulin in human neutrophils.

10p research12 23-04-2013 44 2   Download

Once platelets are activated, the first event tooccur is a rapid change in shape, associated with Ca 2+ /calmodulin-dependent myosin light chain (MLC) phosphorylation and withRhokinase activation. The purpose of this studywas to investigate which is the biochemical pathway that leads to platelet shape change in response to convulxin, a selective GpVI activator, and to verify whether MLC phosphoryla-tion is essential for this process.

7p tumor12 22-04-2013 40 3   Download

Several crystal andNMRstructures of calmodulin (CaM)in complex with fragments derived from CaM-regulated pro-teins have been reported recently and reveal novel ways for CaMto interact with its targets. This review will discuss and compare features of the interaction between CaM and its target domains derived from the plasma membrane Ca 2+ -pump, the Ca 2+ -activated K + -channel, the Ca 2+ / CaM-dependent kinase kinase and the anthrax exotoxin.

11p tumor12 20-04-2013 27 4   Download

The molecular mechanism of the presynaptic neurotoxicity of snake venom phospholipases A2(PLA2s) is not yet fully elucidated. Recently, newhigh-affinity binding proteins for PLA2 toxins have been discovered, including the important intracellular Ca 2+ sensor, calmodulin (CaM). In the present study, the mode of interaction of group IIAPLA2swiththe Ca 2+ -bound form of CaM was investigated by mutational analysis of ammodytoxin A (AtxA) from the long-nosed viper (Vipera ammodytes ammodytes).

8p fptmusic 16-04-2013 40 3   Download

Serine⁄threonine kinase 33 (STK33⁄Stk33) is a recently discovered gene whose inferred amino acid sequence translation displays characters typical for a calcium⁄calmodulin dependent kinase (CAMK). In this study we ana-lysed the STK33⁄Stk33RNA and protein distribution and the localization of the protein. TheSTK33⁄Stk33expression pattern resembles those of some related members of the CAMK group.STK33⁄Stk33displays a non-ubiquitous and, in most tissues, low level of expression.

15p fptmusic 12-04-2013 44 2   Download

Calcium metabolism in oysters is a very complicated and highly controlled physiological and biochemical process. However, the regulation of calcium metabolism in oyster is poorly understood. Our previous study showed that calmodulin (CaM) seemed to play a regulatory role in the process of oyster calcium metabolism. In this study, a full-length cDNA encoding a novel calmodulin-like protein (CaLP) with a long C-terminal sequence was identi-fied from pearl oysterPinctada fucata, expressed in Escherichia coliand characterizedin vitro. ...

12p fptmusic 12-04-2013 41 3   Download

We have previously reported the Ras-dependent activation of the mitogen-activated protein kinases p44 and p42, also termed extracellular signal-regulated kinases (ERK)1 and 2 (ERK1⁄2), mediated through Gs-coupled serotonin receptors transiently expressed in human embryonic kidney (HEK) 293 cells. Whereas G i- and Gq-coupled receptors have been shown to activate Ras through the guanine nucleotide exchange factor (GEF) called Ras-GRF1 (CDC25 Mm ) by binding of Ca 2+ ⁄calmodulin to its N-terminal IQ domain, ...

0p awards 06-04-2013 37 3   Download

The light chain binding domain of rat myosin 1d consists of two IQ-motifs, both of which bind the light chain calmodulin (CaM). To analyze the Myo1d ATPase activity as a function of the IQ-motifs and Ca2+ ⁄CaM binding, we expressed and affinity purified the Myo1d constructs Myo1d-head, Myo1d-IQ1, Myo1d-IQ1.2, Myo1d-IQ2 and Myo1dDLV-IQ2. IQ1 exhibited a high affinity for CaM both in the absence and presence of free Ca 2+ .

9p awards 06-04-2013 58 4   Download

Phosphorylase kinase (PhK) is a large hexadecameric enzyme consisting of four copies of four subunits: (abcd)4. An intrinsic calmodulin (CaM, the d subunit) binds directly to the cprotein kinase chain. The interaction site of CaM onchas been localized to a C-terminal extension of the kinase domain. Two 25-mer peptides derived from this region, PhK5 and PhK13, were identified previously as potential CaM-binding sites.

12p awards 06-04-2013 40 4   Download

The interaction of the adenylate cyclase catalytic domain (AC) of the Bordetella pertussismajor exotoxin with its activator calmodulin (CaM) was studied by time-resolved fluorescence spectroscopy using three fluorescent groups located indifferent regions ofAC: tryptophan residues (W69 and W242), a nucleotide analogue (3¢-anthraniloyl-2¢-deoxyadenosine 5¢-triphosphate, Ant-dATP) and a cysteine-specific probe (acrylodan).

13p dell39 03-04-2013 25 4   Download

We show that epigallocatechin-3 gallate (EGCG), a major component of green tea, stimulates phospholipase D (PLD) activity in U87 human astroglioma cells. EGCG-induced PLD activation was abolished by the phospholipase C (PLC) inhibitor and a lipase inactive PLC-c1mutant, which is dependent on intracellular or extracellular Ca 2+ ,withthe possible involvement of Ca 2+ /calmodulin-dependent pro-teinkinase II (CaMkinase II).

11p dell39 03-04-2013 59 4   Download

Ca 2+ ⁄calmodulin activated protein kinase II (CaMKII) is an oligomeric protein kinase with a unique holoenyzme architecture. The subunits of CaMKII are bound together into the holoenzyme by the association domain, a C-terminal region of
140 residues in the CaMKII polypeptide.

13p dell39 27-03-2013 49 4   Download

Calmodulin (CaM) is a cytosolic Ca 2+ signal-transducing protein that binds and activates many different cellular enzymes with physiological rele-vance, including the nitric oxide synthase (NOS) isozymes. CaM consists of two globular domains joined by a central linker; each domain contains an EF hand pair.

13p inspiron33 26-03-2013 42 4   Download

Humanether a` go-go potassium channels (hEAG1) open in response to membrane depolarization and they are inhibited by Ca 2+ ⁄calmodulin (CaM), presumably binding to the C-terminal domain of the channel sub-units. Deletion of the cytosolic N-terminal domain resulted in complete abolition of Ca 2+ ⁄CaM sensitivity suggesting the existence of further CaM binding sites.

13p inspiron33 26-03-2013 41 5   Download

We have recently shown that acetylated tubulin interacts with plasma mem-brane Na + ,K + -ATPase and inhibits its enzyme activity in several types of cells. H + -ATPase of Saccharomyces cerevisiae is similarly inhibited by interaction with acetylated tubulin.

13p galaxyss3 07-03-2013 33 4   Download

A hydrophilic cation-binding protein, PCaP1, was found to be stably bound to the plasma membrane inArabidopsis thaliana. PCaP1 was quanti-fied to account for 0.03–0.08% of the crude membrane fractions from roots and shoots.

16p media19 06-03-2013 39 3   Download

Different inhibitors of the Ca 2+ ⁄calmodulin-stimulated phosphodiester-ase 1 family have been described and used for the examination of phospho-diesterase 1 in cellular, organ or animal models. However, the inhibitors described differ in potency and selectivity for the different phosphodiester-ase family enzymes, and in part exhibit additional pharmacodynamic actions.

13p media19 04-03-2013 21 2   Download