Regulation of NT-PGC-1α Subcellular Localization and Function by Protein Kinase A-dependent Modulation of Nuclear Export by CRM1

Activation of AMP-activated protein kinase (AMPK) in endothelial cells by vascular endothelial growth factor (VEGF) via the Ca2+/calmodulin-dependent protein kinase kinase 2 (CaMKK2) represents a pro-angiogenic pathway, whose regulation and function is incompletely understood. This study investigates whether the VEGF/AMPK pathway is regulated by cAMP-mediated signalling. We show that cAMP elevation in endothelial cells by forskolin, an activator of the adenylate cyclase, and/or 3-isobutyl-1-methylxanthine (IBMX), an inhibitor of phosphodiesterases, triggers protein kinase A (PKA)-mediated phosphorylation of CaMKK2 (serine residues S495, S511) and AMPK (S487). Phosphorylation of CaMKK2 by PKA led to an inhibition of its activity as measured in CaMKK2 immunoprecipitates of forskolin/IBMX-treated cells. This inhibition was linked to phosphorylation of S495, since it was not seen in cells expressing a non-phosphorylatable CaMKK2 S495C mutant. Phosphorylation of S511 alone in these cells was not able to inhibit CaMKK2 activity. Moreover, phosphorylation of AMPK at S487 was not sufficient to inhibit VEGF-induced AMPK activation in cells, in which PKA-mediated CaMKK2 inhibition was prevented by expression of the CaMKK2 S495C mutant. cAMP elevation in endothelial cells reduced basal and VEGF-induced acetyl-CoA carboxylase (ACC) phosphorylation at S79 even if AMPK was not inhibited. Together, this study reveals a novel regulatory mechanism of VEGF-induced AMPK activation by cAMP/PKA, which may explain, in part, inhibitory effects of PKA on angiogenic sprouting and play a role in balancing pro- and anti-angiogenic mechanisms in order to ensure functional angiogenesis.

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Forskolin, 8-Br-3′,5′-Cyclic Adenosine 5′-Monophosphate, and Catalytic Protein Kinase A Expression in the Nucleus Increase Radioiodide Uptake and Sodium/Iodide Symporter Protein Levels in RET/PTC1-Expressing Cells

The Journal of Clinical Endocrinology & Metabolism ◽

10.1210/jc.2004-1414 ◽

2004 ◽

Vol 89 (12) ◽

pp. 6168-6172 ◽

Cited By ~ 13

Author(s):

Anjli Venkateswaran ◽

Derek K. Marsee ◽

Steven H. Green ◽

Sissy M. Jhiang

Keyword(s):

Protein Kinase ◽

Protein Kinase A ◽

Sodium Iodide ◽

Sodium Iodide Symporter ◽

Thyroid Cells ◽

Protein Levels ◽

And Function ◽

Kinase A

Abstract RET/PTC1, a thyroid-specific oncogene, has been reported to down-regulate sodium/iodide symporter (NIS) expression and function in vitro and in vivo. Recently, RET/PTC1 has been shown to interfere with TSH signaling at multiple levels in thyroid cells. The objective of this study was to investigate whether RET/PTC1-mediated NIS reduction can be rescued by activating cAMP-protein kinase A (PKA) pathways. We showed that both forskolin and 8-Br-cAMP increase radioiodide uptake and NIS protein in RET/PTC1-expressing cells to the same extent as the parental PC Cl 3 cells. We found that RET/PTC1 decreases nuclear localization of catalytic PKA, and forskolin treatment was able to counteract this RET/PTC1 effect. Furthermore, transient expression of catalytic PKA in the nucleus increased radioiodide uptake and NIS protein in RET/PTC1-expressing cells. Taken together, these studies suggest that RET/PTC1 down-regulates NIS expression by interrupting TSH/cAMP signaling, and this RET/PTC1 effect can be reversed by activating cAMP-PKA pathways.

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Regulation and Function of Deiodinases During Decidualization in Female Mice

Endocrinology ◽

10.1210/en.2014-1015 ◽

2014 ◽

Vol 155 (7) ◽

pp. 2704-2717 ◽

Cited By ~ 10

Author(s):

Wen-Bo Deng ◽

Xiao-Huan Liang ◽

Ji-Long Liu ◽

Zeng-Ming Yang

Keyword(s):

Protein Kinase ◽

Protein Kinase A ◽

Early Pregnancy ◽

Stromal Cells ◽

Mouse Uterus ◽

Opposite Strand ◽

And Function ◽

Kinase A

Thyroid dysfunction during human pregnancy is closely related to serious pregnancy outcome. However, the regulation and function of thyroid hormones during early pregnancy are largely unknown. We found that type II deiodinase, an enzyme converting T4 to activated T3, is highly expressed in the mouse uterus on days 3 and 4 of pregnancy. Once the embryo implants into the receptive uterus, type III deiodinase (Dio3), a mainly paternally imprinted gene for inactivating T3, is significantly induced in the stromal cells and accompanied by DNA hypermethylation of intergenic differentially CpG methylation regions in the δ-like 1 homolog-Dio3 imprinting cluster. The concentration of uterine free T3 is actually decreased after embryo implantation. T3 induces Dio3 expression both in vivo and in vitro, suggesting a positive feedback loop. T3 addition or Dio3 knockdown compromises decidualization. These results indicate that the Dio3-mediated local T3 decrease is critical for decidualization of stromal cells during early pregnancy. Furthermore, we found that progesterone regulates Dio3 expression through its cognate receptor both in vivo and in vitro. Additionally, cAMP regulates Dio3 transcription through the protein kinase A-cAMP response element-binding protein pathway. The inhibition of the protein kinase A pathway results in decreased Dio3 expression and impaired decidualization. Dio3 opposite strand (Dio3os) expressed in a similar pattern to Dio3, is transcribed from the opposite strand of Dio3 and fine-tunes Dio3 expression during decidualization. Our data indicate that Dio3 is strongly expressed and tightly controlled during decidualization.

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Isoform-specific subcellular localization and function of protein kinase A identified by mosaic imaging of mouse brain

eLife ◽

10.7554/elife.17681 ◽

2017 ◽

Vol 6 ◽

Cited By ~ 15

Author(s):

Ronit Ilouz ◽

Varda Lev-Ram ◽

Eric A Bushong ◽

Travis L Stiles ◽

Dinorah Friedmann-Morvinski ◽

...

Keyword(s):

Protein Kinase ◽

Subcellular Localization ◽

Protein Kinase A ◽

Mouse Brain ◽

Nuclear Localization ◽

Large Scale ◽

Light And Electron Microscopy ◽

Brain Regions ◽

Creb Phosphorylation ◽

Kinase A

Protein kinase A (PKA) plays critical roles in neuronal function that are mediated by different regulatory (R) subunits. Deficiency in either the RIβ or the RIIβ subunit results in distinct neuronal phenotypes. Although RIβ contributes to synaptic plasticity, it is the least studied isoform. Using isoform-specific antibodies, we generated high-resolution large-scale immunohistochemical mosaic images of mouse brain that provided global views of several brain regions, including the hippocampus and cerebellum. The isoforms concentrate in discrete brain regions, and we were able to zoom-in to show distinct patterns of subcellular localization. RIβ is enriched in dendrites and co-localizes with MAP2, whereas RIIβ is concentrated in axons. Using correlated light and electron microscopy, we confirmed the mitochondrial and nuclear localization of RIβ in cultured neurons. To show the functional significance of nuclear localization, we demonstrated that downregulation of RIβ, but not of RIIβ, decreased CREB phosphorylation. Our study reveals how PKA isoform specificity is defined by precise localization.

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CGI-58/ABHD5 is phosphorylated on Ser239 by protein kinase A: control of subcellular localization

The Journal of Lipid Research ◽

10.1194/jlr.m055004 ◽

2014 ◽

Vol 56 (1) ◽

pp. 109-121 ◽

Cited By ~ 39

Author(s):

Anita Sahu-Osen ◽

Gabriela Montero-Moran ◽

Matthias Schittmayer ◽

Katarina Fritz ◽

Anna Dinh ◽

...

Keyword(s):

Protein Kinase ◽

Subcellular Localization ◽

Protein Kinase A ◽

Kinase A

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Overexpression of human selenoprotein H in neuronal cells enhances mitochondrial biogenesis and function through activation of protein kinase A, protein kinase B, and cyclic adenosine monophosphate response element-binding protein pathway

The International Journal of Biochemistry & Cell Biology ◽

10.1016/j.biocel.2012.11.022 ◽

2013 ◽

Vol 45 (3) ◽

pp. 604-611 ◽

Cited By ~ 18

Author(s):

Suresh L. Mehta ◽

Natalia Mendelev ◽

Santosh Kumari ◽

P. Andy Li

Keyword(s):

Protein Kinase ◽

Protein Kinase A ◽

Mitochondrial Biogenesis ◽

Protein Kinase B ◽

Cyclic Adenosine Monophosphate ◽

Adenosine Monophosphate ◽

Element Binding Protein ◽

And Function ◽

Selenoprotein H ◽

Kinase A

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Multi-state recognition pathway of the intrinsically disordered protein kinase inhibitor by protein kinase A

eLife ◽

10.7554/elife.55607 ◽

2020 ◽

Vol 9 ◽

Cited By ~ 2

Author(s):

Cristina Olivieri ◽

Yingjie Wang ◽

Geoffrey C Li ◽

Manu V S ◽

Jonggul Kim ◽

...

Keyword(s):

Protein Kinase ◽

Protein Kinase A ◽

Nuclear Export ◽

Kinase Inhibitor ◽

Intrinsically Disordered Protein ◽

Protein Kinase Inhibitor ◽

State Recognition ◽

Intrinsically Disordered ◽

Disordered Protein ◽

Kinase A

In the nucleus, the spatiotemporal regulation of the catalytic subunit of cAMP-dependent protein kinase A (PKA-C) is orchestrated by an intrinsically disordered protein kinase inhibitor, PKI, which recruits the CRM1/RanGTP nuclear exporting complex. How the PKA-C/PKI complex assembles and recognizes CRM1/RanGTP is not well understood. Using NMR, SAXS, fluorescence, metadynamics, and Markov model analysis, we determined the multi-state recognition pathway for PKI. After a fast binding step in which PKA-C selects PKI’s most competent conformations, PKI folds upon binding through a slow conformational rearrangement within the enzyme’s binding pocket. The high-affinity and pseudo-substrate regions of PKI become more structured and the transient interactions with the kinase augment the helical content of the nuclear export sequence, which is then poised to recruit the CRM1/RanGTP complex for nuclear translocation. The multistate binding mechanism featured by PKA-C/PKI complex represents a paradigm on how disordered, ancillary proteins (or protein domains) are able to operate multiple functions such as inhibiting the kinase while recruiting other regulatory proteins for nuclear export.

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