The Ser/Thr kinase activity of the Yersinia protein kinase A (YpkA) is necessary for full virulence in the mouse, mollifying phagocytes, and disrupting the eukaryotic cytoskeleton

2006 ◽  
Vol 40 (5) ◽  
pp. 234-243 ◽  
Author(s):  
David J. Wiley ◽  
Roland Nordfeldth ◽  
Jason Rosenzweig ◽  
Christopher J. DaFonseca ◽  
Richard Gustin ◽  
...  
Keyword(s):  
Protein Kinase ◽  
Protein Kinase A ◽  
Kinase Activity ◽  
Kinase A

scholarly journals Complex effects of kinase localization revealed by compartment-specific regulation of protein kinase A activity

2021 ◽  
Author(s):  
Rebecca LaCroix ◽  
Benjamin Lin ◽  
Andre Levchenko
Keyword(s):  
Cell Migration ◽  
Protein Kinase ◽  
Protein Kinase A ◽  
Kinase Activity ◽  
Single Cells ◽  
Regulatory Subunit ◽  
Dependent Manner ◽  
Concentration Dependent Manner ◽  
Specific Regulation ◽  
Kinase A

SummaryKinase activity in signaling networks frequently depends on regulatory subunits that can both inhibit activity by interacting with the catalytic subunits and target the kinase to distinct molecular partners and subcellular compartments. Here, using a new synthetic molecular interaction system, we show that translocation of a regulatory subunit of the protein kinase A (PKA-R) to the plasma membrane has a paradoxical effect on the membrane kinase activity. It can both enhance it at lower translocation levels, even in the absence of signaling inputs, and inhibit it at higher translocation levels, suggesting its role as a linker that can both couple and decouple signaling processes in a concentration-dependent manner. We further demonstrate that superposition of gradients of PKA-R abundance across single cells can control the directionality of cell migration, reversing it at high enough input levels. Thus complex in vivo patterns of PKA-R localization can drive complex phenotypes, including cell migration.

scholarly journals Meprin-β activity modulates the β-catalytic subunit of protein kinase A in ischemia-reperfusion-induced acute kidney injury

2020 ◽  
Vol 318 (5) ◽  
pp. F1147-F1159
Author(s):  
Faihaa Ahmed ◽  
Jean-Marie Mwiza ◽  
Mizpha Fernander ◽  
Ismaila Yahaya ◽  
Shaymaa Abousaad ◽  
...  
Keyword(s):  
Protein Kinase ◽  
Protein Kinase A ◽  
Signaling Pathway ◽  
Kinase Activity ◽  
Ischemia Reperfusion ◽  
Fluorescent Microscopy ◽  
Kidney Tissue ◽  
Kidney Injury ◽  
Catalytic Subunit ◽  
Kinase A

Meprin metalloproteases have been implicated in the progression of kidney injury. Previous work from our group has shown that meprins proteolytically process the catalytic subunit of protein kinase A (PKA-C), resulting in decreased PKA-C kinase activity. The goal of the present study was to determine the PKA-C isoforms impacted by meprin-β and whether meprin-β expression affects downstream mediators of the PKA signaling pathway in ischemia-reperfusion (IR)-induced kidney injury. IR was induced in 12-wk-old male wild-type (WT) and meprin-β knockout (βKO) mice. Madin-Darby canine kidney cells transfected with meprin-β cDNA were also subjected to 2 h of hypoxia. Western blot analysis was used to evaluate levels of total PKA-C, PKA-Cα, PKA-Cβ, phosphorylated (p-)PKA-C, and p-ERK1/2. Meprin-β expression enhanced kidney injury as indicated by levels of neutrophil gelatinase-associated lipocalin and cystatin C. IR-associated decreases were observed in levels of p-PKA-C in kidney tissue from WT mice but not βKO mice, suggesting that meprin-β expression/activity is responsible for the in vivo reduction in kinase activity. Significant increases in levels of PKA-Cβ were observed in kidney lysates for WT mice but not βKO mice at 6 h post-IR. Proximal tubule PKA-Cβ increases in WT but not βKO kidneys were demonstrated by fluorescent microscopy. Furthermore, IR-induced injury was associated with significant increases in p-ERK levels for both genotypes. The present data demonstrate that meprin-β enhances IR-induced kidney injury in part by modulating mediators of the PKA-Cβ signaling pathway.

scholarly journals p21-Activated Kinase 5 (Pak5) Localizes to Mitochondria and Inhibits Apoptosis by Phosphorylating BAD

2003 ◽  
Vol 23 (16) ◽  
pp. 5526-5539 ◽  
Author(s):  
Sophie Cotteret ◽  
Zahara M. Jaffer ◽  
Alexander Beeser ◽  
Jonathan Chernoff
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Protein Kinase ◽  
Protein Kinase A ◽  
Kinase Activity ◽  
Independent Manner ◽  
Promote Neurite Outgrowth ◽  
P21 Activated Kinase ◽  
Kinase A ◽  
Apoptotic Cascade

ABSTRACT Pak5 is the most recently identified and least understood member of the p21-activated kinase (Pak) family. This kinase is known to promote neurite outgrowth in vitro, but its localization, substrates, and effects on cell survival have not been reported. We show here that Pak5 has unique properties that distinguish it from all other members of the Pak family. First, Pak5, unlike Pak1, cannot complement an STE20 mutation in Saccharomyces cerevisiae. Second, Pak5 binds to the GTPases Cdc42 and Rac, but these GTPases do not regulate Pak5 kinase activity, which is constitutive and stronger than any other Pak. Third, Pak5 prevents apoptosis induced by camptothecin and C2-ceramide by phosphorylating BAD on Ser-112 in a protein kinase A-independent manner and prevents the localization of BAD to mitochondria, thereby inhibiting the apoptotic cascade that leads to apoptosis. Finally, we show that Pak5 itself is constitutively localized to mitochondria, and that this localization is independent of kinase activity or Cdc42 binding. These features make Pak5 unique among the Pak family and suggest that it plays an important role in apoptosis through BAD phosphorylation.

scholarly journals Nonclassical Mechanisms of Progesterone Action in the Brain: II. Role of Calmodulin-Dependent Protein Kinase II in Progesterone-Mediated Signaling in the Hypothalamus of Female Rats

Endocrinology ◽  
2008 ◽  
Vol 149 (11) ◽  
pp. 5518-5526 ◽  
Author(s):  
Bhuvana Balasubramanian ◽  
Wendy Portillo ◽  
Andrea Reyna ◽  
Jian Zhong Chen ◽  
Anthony N. Moore ◽  
...  
Keyword(s):  
Protein Kinase C ◽  
Protein Kinase ◽  
Protein Kinase A ◽  
Kinase Activity ◽  
Female Rats ◽  
Dependent Protein Kinase ◽  
Kinase C ◽  
Dependent Protein ◽  
The Brain ◽  
Kinase A

In addition to the activation of classical progestin receptor-dependent genomic pathway, progesterone (P) can activate nonclassical, membrane-initiated signaling pathways in the brain. We recently demonstrated rapid P activation of second-messenger kinases, protein kinase A, and protein kinase C in the ventromedial nucleus (VMN) and preoptic area (POA) of rat brain. To determine whether P can activate yet another Ca+2dependent kinase, we examined the rapid P modulation of calcium and calmodulin-dependent protein kinase II (CaMKII) in the VMN and POA in female rats. A rapid P-initiated activation of CaMKII basal activity was observed in the VMN but not the POA at 30 min. Estradiol benzoate (EB) priming enhanced this CaMKII basal activity in both the VMN and POA. CaMKII protein levels and phosphorylation of Thr-286 moiety on CaMKII, however, remained unchanged with EB and/or P treatments, suggesting that the changes in the CaMKII kinase activity are due to rapid P modulation of the kinase activity and not its synthesis or autoactivation. Furthermore, intracerebroventricular (icv) administration of a CaMKII-specific inhibitor, KN-93, 30 min prior to the P infusion, in EB-primed, ovariectomized female rats inhibited CaMKII activation but not protein kinase A and protein kinase C activities. Interestingly, icv administration of KN-93 30 min prior to P infusion (icv) resulted in a reduction but not total inhibition of P-facilitated lordosis response in EB-primed female rats. These observations suggest a redundancy or, alternately, a hierarchy in the P-regulated activation of kinase signaling cascades in female reproductive behavior.

Mechanism of inhibition of Raf-1 by protein kinase A

1994 ◽  
Vol 14 (10) ◽  
pp. 6696-6703
Author(s):  
S Häfner ◽  
H S Adler ◽  
H Mischak ◽  
P Janosch ◽  
G Heidecker ◽  
...  
Keyword(s):  
Protein Kinase ◽  
Protein Kinase A ◽  
Tyrosine Kinases ◽  
Kinase Activity ◽  
Phorbol Esters ◽  
Kinase Domain ◽  
Amino Terminal ◽  
Mitogenic Signalling ◽  
Pkc Alpha ◽  
Kinase A

The cytoplasmic Raf-1 kinase is essential for mitogenic signalling by growth factors, which couple to tyrosine kinases, and by tumor-promoting phorbol esters such as 12-O-tetradecanoylphorbol-13-acetate, which activate protein kinase C (PKC). Signalling by the Raf-1 kinase can be blocked by activation of the cyclic AMP (cAMP)-dependent protein kinase A (PKA). The molecular mechanism of this inhibition is not precisely known but has been suggested to involve attenuation of Raf-1 binding to Ras. Using purified proteins, we show that in addition to weakening the interaction of Raf-1 with Ras, PKA can inhibit Raf-1 function directly via phosphorylation of the Raf-1 kinase domain. Phosphorylation by PKA interferes with the activation of Raf-1 by either PKC alpha or the tyrosine kinase Lck and even can downregulate the kinase activity of Raf-1 previously activated by PKC alpha or amino-terminal truncation. This type of inhibition can be dissociated from the ability of Raf-1 to associate with Ras, since (i) the isolated Raf-1 kinase domain, which lacks the Ras binding domain, is still susceptible to inhibition by PKA, (ii) phosphorylation of Raf-1 by PKC alpha alleviates the PKA-induced reduction of Ras binding but does not prevent the downregulation of Raf-1 kinase activity by PKA and (iii) cAMP agonists antagonize transformation by v-Raf, which is Ras independent.

scholarly journals Adeno-Associated Virus Rep78 Protein Interacts with Protein Kinase A and Its Homolog PRKX and Inhibits CREB-Dependent Transcriptional Activation

1998 ◽  
Vol 72 (10) ◽  
pp. 7916-7925 ◽  
Author(s):  
Giovanni Di Pasquale ◽  
Simon N. Stacey
Keyword(s):  
Protein Kinase ◽  
Protein Kinase A ◽  
Transcriptional Activation ◽  
Expression Vector ◽  
Kinase Activity ◽  
Helper Virus ◽  
Regulation Of Transcription ◽  
Adeno Associated Virus ◽  
Kinase A

ABSTRACT Adeno-associated virus (AAV) is a human parvovirus of the genusDependovirus. AAV replication is largely restricted to cells which are coinfected with a helper virus. In the absence of a helper virus, the AAV genome can integrate into a specific chromosomal site where it remains latent until reactivated by superinfection of the host cell with an appropriate helper virus. Replication functions of AAV have been mapped to the Rep68 and Rep78 gene products. Rep proteins demonstrate DNA binding, endonuclease, and helicase activities and are involved in regulation of transcription from both AAV and heterologous promoters. AAV has been associated with suppression of oncogenicity in a range of viral and nonviral tumors. In this study we sought to identify and study cellular protein targets of AAV Rep, in order to develop a better understanding of the various activities of Rep. We used the yeast two-hybrid system to identify HeLa cell proteins that interact with AAV type 2 Rep78. We isolated several strongly interacting clones which were subsequently identified as PRKX (previously named PKX1), a recently described homolog of the protein kinase A (PKA) catalytic subunit (PKAc). The interaction was confirmed in vitro by using pMal-Rep pull-down assays. The region of Rep78 which interacts was mapped to a C-terminal zinc finger-like domain; Rep68, which lacks this domain, did not interact with PRKX. PRKX demonstrated autophosphorylation and kinase activity towards histone H1 and a PKA oligopeptide target. Autophosphorylation was inhibited by interaction with Rep78. In transfection assays, a PRKX expression vector was shown to be capable of activating CREB-dependent transcription. This activation was suppressed by Rep78 but not by Rep68. Since PRKX is a close homolog of PKAc, we investigated whether Rep78 could interact directly with PKAc. pMal-Rep78 was found to associate with purified PKAc and inhibited its kinase activity. Cotransfection experiments demonstrated that Rep78 could block the activation of CREB by a PKAc expression vector. These experiments suggest that AAV may perturb normal cyclic AMP response pathways in infected cells.

scholarly journals Mechanism of inhibition of Raf-1 by protein kinase A.

1994 ◽  
Vol 14 (10) ◽  
pp. 6696-6703 ◽  
Author(s):  
S Häfner ◽  
H S Adler ◽  
H Mischak ◽  
P Janosch ◽  
G Heidecker ◽  
...  
Keyword(s):  
Protein Kinase ◽  
Protein Kinase A ◽  
Tyrosine Kinases ◽  
Kinase Activity ◽  
Phorbol Esters ◽  
Kinase Domain ◽  
Amino Terminal ◽  
Mitogenic Signalling ◽  
Pkc Alpha ◽  
Kinase A

The cytoplasmic Raf-1 kinase is essential for mitogenic signalling by growth factors, which couple to tyrosine kinases, and by tumor-promoting phorbol esters such as 12-O-tetradecanoylphorbol-13-acetate, which activate protein kinase C (PKC). Signalling by the Raf-1 kinase can be blocked by activation of the cyclic AMP (cAMP)-dependent protein kinase A (PKA). The molecular mechanism of this inhibition is not precisely known but has been suggested to involve attenuation of Raf-1 binding to Ras. Using purified proteins, we show that in addition to weakening the interaction of Raf-1 with Ras, PKA can inhibit Raf-1 function directly via phosphorylation of the Raf-1 kinase domain. Phosphorylation by PKA interferes with the activation of Raf-1 by either PKC alpha or the tyrosine kinase Lck and even can downregulate the kinase activity of Raf-1 previously activated by PKC alpha or amino-terminal truncation. This type of inhibition can be dissociated from the ability of Raf-1 to associate with Ras, since (i) the isolated Raf-1 kinase domain, which lacks the Ras binding domain, is still susceptible to inhibition by PKA, (ii) phosphorylation of Raf-1 by PKC alpha alleviates the PKA-induced reduction of Ras binding but does not prevent the downregulation of Raf-1 kinase activity by PKA and (iii) cAMP agonists antagonize transformation by v-Raf, which is Ras independent.

scholarly journals Inhibition of the mitochondrial permeability transition by protein kinase A in rat liver mitochondria and hepatocytes

2010 ◽  
Vol 431 (3) ◽  
pp. 411-421 ◽  
Author(s):  
Peter Pediaditakis ◽  
Jae-Sung Kim ◽  
Lihua He ◽  
Xun Zhang ◽  
Lee M. Graves ◽  
...  
Keyword(s):  
Protein Kinase ◽  
Protein Kinase A ◽  
Kinase Activity ◽  
Mitochondrial Permeability Transition ◽  
Permeability Transition ◽  
Liver Mitochondria ◽  
Rat Liver Mitochondria ◽  
Liver Cytosol ◽  
Mitochondrial Permeability ◽  
Kinase A

NO and cGMP administered at reperfusion after ischaemia prevent injury to hepatocytes mediated by the MPT (mitochondrial permeability transition). To characterize further the mechanism of protection, the ability of hepatic cytosol in combination with cyclic nucleotides to delay onset of the calcium-induced MPT was evaluated in isolated rat liver mitochondria. Liver cytosol plus cGMP or cAMP dose-dependently inhibited the MPT, required ATP hydrolysis for inhibition and did not inhibit mitochondrial calcium uptake. Specific peptide inhibitors for PKA (protein kinase A), but not PKG (protein kinase G), abolished cytosol-induced inhibition of MPT onset. Activity assays showed a cGMP- and cAMP-stimulated protein kinase activity in liver cytosol that was completely inhibited by PKI, a PKA peptide inhibitor. Size-exclusion chromatography of liver cytosol produced a single peak of cGMP/cAMP-stimulated kinase activity with an estimated protein size of 180–220 kDa. This fraction was PKI-sensitive and delayed onset of the MPT. Incubation of active catalytic PKA subunit directly with mitochondria in the absence of cytosol and cyclic nucleotide also delayed MPT onset, and incubation with purified outer membranes led to phosphorylation of a major 31 kDa band. After ischaemia, administration at reperfusion of membrane-permeant cAMPs and cAMP-mobilizing glucagon prevented reperfusion injury to hepatocytes. In conclusion, PKA in liver cytosol activated by cGMP or cAMP acts directly on mitochondria to delay onset of the MPT and protect hepatocytes from cell death after ischaemia/reperfusion.

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