scholarly journals Interactive Role of Protein Phosphatase 2A and Protein Kinase Cα in the Stretch-Induced Triphosphorylation of Myosin Light Chain in Canine Cerebral Artery

2010 ◽  
Vol 47 (2) ◽  
pp. 115-127 ◽  
Author(s):  
Kazuo Obara ◽  
Ayako Mitate ◽  
Kayo Nozawa ◽  
Makiko Watanabe ◽  
Yoshihiko Ito ◽  
...  
Keyword(s):  
Protein Kinase C ◽  
Protein Kinase ◽  
Cerebral Artery ◽  
Light Chain ◽  
Protein Phosphatase ◽  
Myosin Light Chain ◽  
Protein Phosphatase 2A ◽  
Kinase C ◽  
Phosphatase 2A

scholarly journals Protein Kinase C Controls Binding of Igo/ENSA Proteins to Protein Phosphatase 2A in Budding Yeast

2017 ◽  
Vol 292 (12) ◽  
pp. 4925-4941 ◽  
Author(s):  
Vu Thai ◽  
Noah Dephoure ◽  
Amit Weiss ◽  
Jacqueline Ferguson ◽  
Ricardo Leitao ◽  
...  
Keyword(s):  
Protein Kinase C ◽  
Protein Kinase ◽  
Protein Phosphatase ◽  
Budding Yeast ◽  
Protein Phosphatase 2A ◽  
Kinase C ◽  
Phosphatase 2A

Shrinkage-induced activation of Na+/H+ exchange in primary rat astrocytes: role of myosin light-chain kinase

1995 ◽  
Vol 269 (1) ◽  
pp. C257-C266 ◽  
Author(s):  
L. D. Shrode ◽  
J. D. Klein ◽  
W. C. O'Neill ◽  
R. W. Putnam
Keyword(s):  
Protein Kinase C ◽  
Protein Kinase ◽  
Light Chain ◽  
Myosin Light Chain Kinase ◽  
Myosin Light Chain ◽  
Tetraacetic Acid ◽  
Maximal Inhibition ◽  
Kinase C ◽  
Rat Astrocytes

Primary rat astrocytes exposed to hyperosmotic solutions undergo Na(+)-dependent amiloride-sensitive alkalinization of 0.36 U [measured with the pH-sensitive fluorescent dye 2',7'-bis(carboxyethyl)-5(6)-carboxy-fluorescein], suggesting that shrinkage-induced alkalinization is due to activation of Na+/H+ exchange (NHE). Alkalinization is maintained for at least 20 min, and is readily reversible and ATP dependent. Hyperosmotic solutions produced no increase of intracellular Ca2+ or adenosine 3',5'-cyclic monophosphate (cAMP). Loading cells with 1,2-bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid, a Ca2+ chelator, or depleting cells of protein kinase C (PKC) had no effect on activation of NHE. Thus shrinkage-induced activation of NHE does not involve cAMP, Ca2+, or PKC. However, ML-7, an inhibitor of myosin light-chain kinase (MLCK), inhibited shrinkage-induced activation with a half-maximal inhibition of 56 microM. This activation was also inhibited by 500 microM N-(6-aminohexyl)-5-chloro-1-naphthalenesulfonamide, 100 microM chlorpromazine, and 50 microM trifluoperazine, all calmodulin inhibitors. Shrinkage increased the phosphorylation of an 18-kDa protein that colocalizes with myosin light chain. Our data suggest that shrinkage-induced activation of NHE in astrocytes occurs via a novel pathway involving activation of calmodulin-dependent MLCK and phosphorylation of myosin light chain.

Sealing effects of (−)-epigallocatechin gallate on protein kinase C and protein phosphatase 2A

1997 ◽  
Vol 65 (2-3) ◽  
pp. 157-164 ◽  
Author(s):  
Katsuhisa Kitano ◽  
Ki-Youl Nam ◽  
Shunsaku Kimura ◽  
Hirota Fujiki ◽  
Yukio Imanishi
Keyword(s):  
Protein Kinase C ◽  
Protein Kinase ◽  
Protein Phosphatase ◽  
Protein Phosphatase 2A ◽  
Epigallocatechin Gallate ◽  
Kinase C ◽  
Phosphatase 2A

scholarly journals Persistent Activation of RelA by Respiratory Syncytial Virus Involves Protein Kinase C, Underphosphorylated IκBβ, and Sequestration of Protein Phosphatase 2A by the Viral Phosphoprotein

1998 ◽  
Vol 72 (7) ◽  
pp. 5610-5618 ◽  
Author(s):  
Vira Bitko ◽  
Sailen Barik
Keyword(s):  
Protein Kinase C ◽  
Respiratory Syncytial Virus ◽  
Protein Kinase ◽  
Protein Phosphatase ◽  
Protein Phosphatase 2A ◽  
Oxygen Intermediates ◽  
Kinase C ◽  
Phosphatase 2A ◽  
Initial Activation ◽  
Syncytial Virus

ABSTRACT Respiratory syncytial virus (RSV) activated the RelA (p65) subunit of nuclear factor kappa B (NF-κB) over many hours postinfection. The initial activation coincided with phosphorylation and degradation of IκBα, the cytoplasmic inhibitor of RelA. During persistent activation of NF-κB at later times in infection, syntheses of inhibitors IκBα as well as IκBβ were restored. However, the resynthesized IκBβ was in an underphosphorylated state, which apparently prevented inhibition of NF-κB. Use of specific inhibitors suggested that the pathway leading to the persistent—but not the initial—activation of NF-κB involved signaling through protein kinase C (PKC) and reactive oxygen intermediates of nonmitochondrial origin, whereas phospholipase C or D played little or no role. Thus, RSV infection led to the activation of NF-κB by a biphasic mechanism: a transient or early activation involving phosphorylation of the inhibitor IκB polypeptides, and a persistent or long-term activation requiring PKC and the generation of hypophosphorylated IκBβ. At least a part of the activation was through a novel mechanism in which the viral phosphoprotein P associated with but was not dephosphorylated by protein phosphatase 2A and thus sequestered and inhibited the latter. We postulate that this led to a net increase in the phosphorylation state of signaling proteins that are responsible for RelA activation.

scholarly journals Regulation of Organelle Movement in Melanophores by Protein Kinase A (PKA), Protein Kinase C (PKC), and Protein Phosphatase 2A (PP2A)

1998 ◽  
Vol 142 (3) ◽  
pp. 803-813 ◽  
Author(s):  
Amy R. Reilein ◽  
Irina S. Tint ◽  
Natalia I. Peunova ◽  
Grigori N. Enikolopov ◽  
Vladimir I. Gelfand
Keyword(s):  
Protein Kinase C ◽  
Protein Kinase ◽  
Protein Kinase A ◽  
Protein Phosphatase ◽  
Protein Phosphatase 2A ◽  
Organelle Transport ◽  
Pigment Dispersion ◽  
Kinase C ◽  
Phosphatase 2A ◽  
Kinase A

We used melanophores, cells specialized for regulated organelle transport, to study signaling pathways involved in the regulation of transport. We transfected immortalized Xenopus melanophores with plasmids encoding epitope-tagged inhibitors of protein phosphatases and protein kinases or control plasmids encoding inactive analogues of these inhibitors. Expression of a recombinant inhibitor of protein kinase A (PKA) results in spontaneous pigment aggregation. α-Melanocyte-stimulating hormone (MSH), a stimulus which increases intracellular cAMP, cannot disperse pigment in these cells. However, melanosomes in these cells can be partially dispersed by PMA, an activator of protein kinase C (PKC). When a recombinant inhibitor of PKC is expressed in melanophores, PMA-induced pigment dispersion is inhibited, but not dispersion induced by MSH. We conclude that PKA and PKC activate two different pathways for melanosome dispersion. When melanophores express the small t antigen of SV-40 virus, a specific inhibitor of protein phosphatase 2A (PP2A), aggregation is completely prevented. Conversely, overexpression of PP2A inhibits pigment dispersion by MSH. Inhibitors of protein phosphatase 1 and protein phosphatase 2B (PP2B) do not affect pigment movement. Therefore, melanosome aggregation is mediated by PP2A.

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