scholarly journals The Arabidopsis Calcium Sensor Calcineurin B-Like 3 Inhibits the 5′-Methylthioadenosine Nucleosidase in a Calcium-Dependent Manner

2008 ◽  
Vol 148 (4) ◽  
pp. 1883-1896 ◽  
Author(s):  
Seung-Ick Oh ◽  
Jimyeong Park ◽  
Sunhee Yoon ◽  
Yungyeong Kim ◽  
Soojin Park ◽  
...  
Keyword(s):  
Dependent Manner ◽  
Calcium Sensor ◽  
Calcium Dependent ◽  
Calcineurin B

scholarly journals Regulation of ABA-Non-Activated SNF1-Related Protein Kinase 2 Signaling Pathways by Phosphatidic Acid

2020 ◽  
Vol 21 (14) ◽  
pp. 4984
Author(s):  
Maria Klimecka ◽  
Maria Bucholc ◽  
Justyna Maszkowska ◽  
Ewa Krzywińska ◽  
Grażyna Goch ◽  
...  
Keyword(s):  
Subcellular Localization ◽  
Phosphatidic Acid ◽  
Protein Phosphatase ◽  
Plant Cells ◽  
Dependent Manner ◽  
Calcium Sensor ◽  
Related Protein ◽  
Plant Growth And Development ◽  
Calcium Dependent ◽  
Aba Insensitive

Phosphatidic acid (PA) is involved in the regulation of plant growth and development, as well as responses to various environmental stimuli. Several PA targets in plant cells were identified, including two SNF1-related protein kinases 2 (SnRK2s), SnRK2.10 and SnRK2.4, which are not activated by abscisic acid (ABA). Here, we investigated the effects of PA on various elements of ABA-non-activated SnRK2 signaling. PA 16:0/18:1 was found to modulate the SnRK2 structure and the phosphorylation of some SnRK2 targets. Conversely, phosphorylation by the ABA-non-activated SnRK2s, of one of such targets, dehydrin Early Responsive to Dehydration 14 (ERD14), affects its interaction with PA and subcellular localization. Moreover, PA 16:0/18:1 modulates the activity and/or localization of negative regulators of the ABA-non-activated SnRK2s, not only of the ABA insensitive 1 (ABI1) phosphatase, which was identified earlier, but also of another protein phosphatase 2C, PP2CA. The activity of both phosphatases was inhibited by about 50% in the presence of 50 μM PA. PA 16:0/18:1 also impacts the phosphorylation and subcellular localization of SnRK2-interacting calcium sensor, known to inhibit SnRK2 activity in a calcium-dependent manner. Thus, PA was found to regulate ABA-non-activated SnRK2 signaling at several levels: the activity, phosphorylation status and/or localization of SnRK2 cellular partners.

scholarly journals Ca2+-Dependent Protein Kinase 6 Enhances KAT2 Shaker Channel Activity in Arabidopsis thaliana

2021 ◽  
Vol 22 (4) ◽  
pp. 1596
Author(s):  
Elsa Ronzier ◽  
Claire Corratgé-Faillie ◽  
Frédéric Sanchez ◽  
Christian Brière ◽  
Tou Cheu Xiong
Keyword(s):  
Arabidopsis Thaliana ◽  
Resonance Energy Transfer ◽  
Resonance Energy ◽  
Physical Interaction ◽  
Fluorescence Lifetime Imaging ◽  
Dependent Manner ◽  
In Planta ◽  
Knock Out ◽  
Calcium Dependent ◽  
Dependent Protein

Post-translational regulations of Shaker-like voltage-gated K+ channels were reported to be essential for rapid responses to environmental stresses in plants. In particular, it has been shown that calcium-dependent protein kinases (CPKs) regulate Shaker channels in plants. Here, the focus was on KAT2, a Shaker channel cloned in the model plant Arabidopsis thaliana, where is it expressed namely in the vascular tissues of leaves. After co-expression of KAT2 with AtCPK6 in Xenopuslaevis oocytes, voltage-clamp recordings demonstrated that AtCPK6 stimulates the activity of KAT2 in a calcium-dependent manner. A physical interaction between these two proteins has also been shown by Förster resonance energy transfer by fluorescence lifetime imaging (FRET-FLIM). Peptide array assays support that AtCPK6 phosphorylates KAT2 at several positions, also in a calcium-dependent manner. Finally, K+ fluorescence imaging in planta suggests that K+ distribution is impaired in kat2 knock-out mutant leaves. We propose that the AtCPK6/KAT2 couple plays a role in the homeostasis of K+ distribution in leaves.

scholarly journals Regulation of neuronal axon specification by glia-neuron gap junctions in C. elegans

eLife ◽  
2016 ◽  
Vol 5 ◽  
Author(s):  
Lingfeng Meng ◽  
Albert Zhang ◽  
Yishi Jin ◽  
Dong Yan
Keyword(s):  
Gap Junctions ◽  
Glial Cells ◽  
Neuronal Development ◽  
Dependent Manner ◽  
Critical Step ◽  
C Elegans ◽  
Calcium Dependent ◽  
Intracellular Pathways ◽  
Axon Specification

Axon specification is a critical step in neuronal development, and the function of glial cells in this process is not fully understood. Here, we show that C. elegans GLR glial cells regulate axon specification of their nearby GABAergic RME neurons through GLR-RME gap junctions. Disruption of GLR-RME gap junctions causes misaccumulation of axonal markers in non-axonal neurites of RME neurons and converts microtubules in those neurites to form an axon-like assembly. We further uncover that GLR-RME gap junctions regulate RME axon specification through activation of the CDK-5 pathway in a calcium-dependent manner, involving a calpain clp-4. Therefore, our study reveals the function of glia-neuron gap junctions in neuronal axon specification and shows that calcium originated from glial cells can regulate neuronal intracellular pathways through gap junctions.

scholarly journals Specificity and Prevalence of Natural Bovine Antimannan Antibodies

1999 ◽  
Vol 6 (6) ◽  
pp. 946-952 ◽  
Author(s):  
Abhay Srinivasan ◽  
Yawei Ni ◽  
Ian Tizard
Keyword(s):  
Age Groups ◽  
Inhibitory Effect ◽  
Enzyme Linked Immunosorbent Assay ◽  
Dependent Manner ◽  
Serum Samples ◽  
Adult Cattle ◽  
Calcium Dependent ◽  
High Concentrations ◽  
Carbohydrate Components ◽  
A Minor

ABSTRACT Immune responses to the carbohydrate components of microorganisms, mediated both by antibodies and by lectins, are an important part of host defense. In the present experiments, the specificity and presence of natural bovine antibodies against mannan, a common fungal antigen, were examined by enzyme-linked immunosorbent assay (ELISA), usingSaccharomyces cerevisiae mannan as an antigen. The results showed that all serum samples from animals of three age groups (newborn, calf, and adult) tested contained antimannan antibodies, and the titer of these antibodies increased significantly in adults. However, titers among individual adult cattle differed widely. Inhibition assays showed that yeast mannan was the strongest inhibitor.d-Mannose exhibited only a minor inhibitory effect at high concentrations. This suggests that most of these antibodies recognize an oligosaccharide-based epitope(s) different from those recognized by lectins. Cattle possess three serum C-type lectins (collectins) capable of recognizing mannan in a calcium-dependent manner. Addition of EDTA to the reaction did not reduce antibody binding, suggesting that the binding of these antibodies to mannan was not affected by the presence of collectin. The antibodies purified from either calf or adult serum by mannan-Sepharose affinity chromatography consisted of mainly immunoglobulin G (IgG) and a smaller amount of IgM. IgG1 was shown to be the dominant antimannan IgG isotype by isotype-specific ELISA. Together, these results demonstrate the production of natural antimannan antibodies in cattle in an age-dependent manner. These antibodies might be involved in defending the host against mannan-containing pathogens as a specific line of defense in conjunction with the innate response by lectins.

scholarly journals Microinjection of Ca++-calmodulin causes a localized depolymerization of microtubules.

1983 ◽  
Vol 97 (6) ◽  
pp. 1918-1924 ◽  
Author(s):  
C Keith ◽  
M DiPaola ◽  
F R Maxfield ◽  
M L Shelanski
Keyword(s):  
Mitotic Spindle ◽  
Calcium Ion ◽  
Molar Ratio ◽  
Free Calcium ◽  
Local Concentration ◽  
Dependent Manner ◽  
Calcium Dependent ◽  
Molar Ratios ◽  
Microtubule Polymerization ◽  
Full Complement

The microinjection of calcium-saturated calmodulin into living fibroblasts causes the rapid disruption of microtubules and stress fibers in a sharply delimited region concentric with the injection site. This effect is specific to the calcium-bearing form of calmodulin; neither calcium-free calmodulin nor calcium ion at similar levels affects the cytoskeleton. If cells have previously been microinjected with calcium-free calmodulin, elevation of their intracellular calcium levels to 25 mM potentiates the disruption of microtubules throughout the cytoplasm. Approximately 400 mM free calcium is required to cause an equivalent disruption in uninjected cells. The level of calmodulin necessary to disrupt the full complement of cellular microtubules is found to be approximately in 2:1 molar ratio to tubulin dimer. These results indicate that calmodulin can be localized within the cytoplasm in a calcium-dependent manner and that it can act to regulate the calcium lability of microtubules at molar ratios that could be achieved locally within the cell. Our results are consistent with the hypothesis that calmodulin may be controlling microtubule polymerization equilibria in areas of high local concentration such as the mitotic spindle.

Characterization of a cDNA encoding a novel band 4.1-like protein in zebrafish

1997 ◽  
Vol 75 (5) ◽  
pp. 623-632 ◽  
Author(s):  
Gregory M Kelly ◽  
Bruno Reversade
Keyword(s):  
Cell Communication ◽  
Membrane Skeleton ◽  
Adult Brain ◽  
Dependent Manner ◽  
Midblastula Transition ◽  
Protein 4.1 ◽  
Calcium Dependent ◽  
Calcium Calmodulin Dependent ◽  
Integral Role

Membrane skeleton protein 4.1 and other members of a family of proteins that link the cytoskeleton to the plasma membrane may play an integral role in cell communication during development. The polymerase chain reaction and degenerate oligodeoxynucleotide primers to consensus sequences in the putative membrane-binding domain of the protein 4.1 superfamily were used to isolate cDNAs encoding members of the zebrafish protein 4.1 family. Zebrafish stage- and tissue-specific first strand cDNA was used in the PCR. After the reaction, amplicons of the predicted size were sequenced to confirm their relationship to the protein 4.1 superfamily. One cDNA, with a high degree of similarity to a mouse novel band 4.1-like cDNA, was used to probe a zebrafish adult brain library. A 2.4-kb cDNA was isolated and found to encode a 619 amino acid polypeptide homologous to mouse novel band 4.1-like protein 4. Zebrafish nbl4 mRNA is maternally supplied and is expressed throughout embryogenesis. In adults, nbl4 is found in the ovary, eye, heart, and brain, but not in gut or skeletal muscle. When synthetic nbl4 mRNA is translated in vitro it binds calmodulin in a calcium-dependent manner. These data indicate that zebrafish nbl4 is a maternal transcript owing to its presence before the midblastula transition, and it is present later on in specific adult structures. The ability to bind calmodulin would suggest that the function of nbl4 protein may be potentially regulated via a calcium-calmodulin dependent mechanism.

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