scholarly journals Simultaneous readout of multiple FRET pairs using photochromism

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Thijs Roebroek ◽  
Wim Vandenberg ◽  
François Sipieter ◽  
Siewert Hugelier ◽  
Christophe Stove ◽  
...  
Keyword(s):  
Emission Spectra ◽  
Dependent Protein Kinase ◽  
Extracellular Signal Regulated Kinase ◽  
Extracellular Signal ◽  
Donor And Acceptor ◽  
Powerful Approach ◽  
Dependent Protein ◽  
Erk Activity ◽  
Powerful Mechanism

AbstractFörster resonant energy transfer (FRET) is a powerful mechanism to probe associations in situ. Simultaneously performing more than one FRET measurement can be challenging due to the spectral bandwidth required for the donor and acceptor fluorophores. We present an approach to distinguish overlapping FRET pairs based on the photochromism of the donor fluorophores, even if the involved fluorophores display essentially identical absorption and emission spectra. We develop the theory underlying this method and validate our approach using numerical simulations. To apply our system, we develop rsAKARev, a photochromic biosensor for cAMP-dependent protein kinase (PKA), and combine it with the spectrally-identical biosensor EKARev, a reporter for extracellular signal-regulated kinase (ERK) activity, to deliver simultaneous readout of both activities in the same cell. We further perform multiplexed PKA, ERK, and calcium measurements by including a third, spectrally-shifted biosensor. Our work demonstrates that exploiting donor photochromism in FRET can be a powerful approach to simultaneously read out multiple associations within living cells.

scholarly journals Simultaneous readout of multiple FRET pairs using photochromism

2021 ◽  
Author(s):  
Thijs Roebroek ◽  
Wim Vandenberg ◽  
François Sipieter ◽  
Siewert Hugelier ◽  
Christophe Stove ◽  
...  
Keyword(s):  
Kinase Activity ◽  
Spectral Band ◽  
Emission Spectra ◽  
Living Cells ◽  
Donor And Acceptor ◽  
Powerful Approach ◽  
Resonant Energy Transfer ◽  
Powerful Mechanism ◽  
Erk Kinase

AbstractFörster resonant energy transfer (FRET) is a powerful mechanism to probe associations in situ. Simultaneously performing more than one FRET measurement can be challenging due to the spectral band-width required for the donor and acceptor fluorophores. We present an approach to distinguish overlapping FRET pairs based on the photochromism of the donor fluorophores, even if the involved fluorophores display essentially identical absorption and emission spectra. We develop the theory underlying this method and validate our approach using numerical simulations. To apply our system, we develop rsAKARev, a photochromic biosensor for cAMP-dependent kinase (PKA), and combine it with the spectrally-identical biosensor EKARev, a reporter for ERK kinase activity, to deliver simultaneous readout of both activities in the same cell. We further perform multiplexed PKA, ERK, and calcium measurements by including a third, spectrally-shifted biosensor. Our work demonstrates that exploiting donor photochromism in FRET can be a powerful approach to simultaneously read out multiple associations within living cells.

Evidence for the involvement of CaMKII and AMPK in Ca2+-dependent signaling pathways regulating FA uptake and oxidation in contracting rodent muscle

2008 ◽  
Vol 104 (5) ◽  
pp. 1366-1373 ◽  
Author(s):  
Marcella A. Raney ◽  
Lorraine P. Turcotte
Keyword(s):  
Electrical Stimulation ◽  
Protein Kinase ◽  
Dependent Protein Kinase ◽  
Extracellular Signal Regulated Kinase ◽  
Calcium Calmodulin Dependent ◽  
Extracellular Signal ◽  
Regulation Of Contraction ◽  
Dependent Protein ◽  
Ampk Activity ◽  
Amp Activated Protein Kinase

Calcium-calmodulin/dependent protein kinase II (CaMKII), AMP-activated protein kinase (AMPK), and extracellular signal-regulated kinase (ERK1/2) have each been implicated in the regulation of substrate metabolism during exercise. The purpose of this study was to determine whether CaMKII is involved in the regulation of FA uptake and oxidation and, if it is involved, whether it does so independently of AMPK and ERK1/2. Rat hindquarters were perfused at rest with ( n = 16) or without ( n = 10) 3 mM caffeine, or during electrical stimulation ( n = 14). For each condition, rats were subdivided and treated with 10 μM of either KN92 or KN93, inactive and active CaMKII inhibitors, respectively. Both caffeine treatment and electrical stimulation significantly increased FA uptake and oxidation. KN93 abolished caffeine-induced FA uptake, decreased contraction-induced FA uptake by 33%, and abolished both caffeine- and contraction-induced FA oxidation ( P < 0.05). Caffeine had no effect on ERK1/2 phosphorylation ( P > 0.05) and increased α2-AMPK activity by 68% ( P < 0.05). Electrical stimulation increased ERK1/2 phosphorylation and α2-AMPK activity by 51% and 3.4-fold, respectively ( P < 0.05). KN93 had no effect on caffeine-induced α2-AMPK activity, ERK1/2 phosphorylation, or contraction-induced ERK1/2 phosphorylation ( P > 0.05). Alternatively, it decreased contraction-induced α2-AMPK activity by 51% ( P < 0.05), suggesting that CaMKII lies upstream of AMPK. These results demonstrate that regulation of contraction-induced FA uptake and oxidation occurs in part via Ca2+-independent activation of ERK1/2 as well as Ca2+-dependent activation of CaMKII and AMPK.

scholarly journals Cyclic AMP-Dependent Kinase Regulates Raf-1 Kinase Mainly by Phosphorylation of Serine 259

2002 ◽  
Vol 22 (10) ◽  
pp. 3237-3246 ◽  
Author(s):  
Amardeep S. Dhillon ◽  
Claire Pollock ◽  
Helge Steen ◽  
Peter E. Shaw ◽  
Harald Mischak ◽  
...  
Keyword(s):  
Cyclic Amp ◽  
Kinase Activity ◽  
Dependent Manner ◽  
Dependent Protein Kinase ◽  
Extracellular Signal Regulated Kinase ◽  
Extracellular Signal ◽  
Dependent Protein ◽  
Kinase Pathway

ABSTRACT The Raf-1 kinase activates the ERK (extracellular-signal-regulated kinase) pathway. The cyclic AMP (cAMP)-dependent protein kinase (PKA) can inhibit Raf-1 by direct phosphorylation. We have mapped all cAMP-induced phosphorylation sites in Raf-1, showing that serines 43, 259, and 621 are phosphorylated by PKA in vitro and induced by cAMP in vivo. Serine 43 phosphorylation decreased the binding to Ras in serum-starved but not in mitogen-stimulated cells. However, the kinase activity of a RafS43A mutant was fully inhibited by PKA. Mutation of serine 259 increased the basal Raf-1 activity and rendered it largely resistant to inhibition by PKA. cAMP increased Raf-1 serine 259 phosphorylation in a PKA-dependent manner with kinetics that correlated with ERK deactivation. PKA also decreased Raf-1 serine 338 phosphorylation of Raf-1, previously shown to be required for Raf-1 activation. Serine 338 phosphorylation of a RafS259A mutant was unaffected by PKA. Using RafS259 mutants we also demonstrate that Raf-1 is the sole target for PKA inhibition of ERK and ERK-induced gene expression, and that Raf-1 inhibition is mediated mainly through serine 259 phosphorylation.

scholarly journals The Antiemetic Effect of Xiao-Ban-Xia-Tang Formula is Associated With Regulating CaM/CaMKII/ERK1/2 Signaling Pathway in Cisplatin and 1-phenylbiguanide Hydrochloride Induced Rat Pica Models

2020 ◽  
Author(s):  
Lei Xia ◽  
Yihong Xian ◽  
Xiaodi Feng ◽  
Qianqian Cheng ◽  
Siqi Chen ◽  
...  
Keyword(s):  
Small Intestine ◽  
Signaling Pathway ◽  
Underlying Mechanism ◽  
Dependent Protein Kinase ◽  
Antiemetic Effect ◽  
Extracellular Signal Regulated Kinase ◽  
Chinese Herbal ◽  
Extracellular Signal ◽  
Male Wistar Rats ◽  
Dependent Protein

Abstract Background: Xiao-Ban-Xia-Tang (XBXT) formula is a traditional Chinese herbal formula for treating emesis. Chemotherapy-induced nausea and vomiting (CINV) are serious side effects of chemotherapy, which was closely related to the activation of 5-hydroxytryptamine 3 receptor (5-HT3R). In this paper, the effect of XBXT on cisplatin- and 1-phenylbiguanide hydrochloride (1-PBG, a selective 5-HT3R agonist)- induced pica behavior in male Wistar rats and inhibition of calmodulin/calmodulin-dependent protein kinase II/extracellular signal-regulated kinase 1/2 (CaM/CaMKII/ERK1/2) signaling pathway were investigated. Methods: XBXT (1.6 g/kg, twice daily) was orally administered from day 1 after intraperitoneal injection of cisplatin (6 mg/kg) and 1-PBG (25 mg/kg) to day 3. Pica behavior (consumption of kaolin, a type of clay) was recorded every 24 h. The expression and co-localization of CaM and 5-HT3R in small intestine and brain were detected by immunofluorescence. The expression of CaMKII, pCaMKII, ERK1/2, and pERK1/2 proteins were detected by Western blot. Results: XBXT treatment significantly decreased kaolin ingestion (pica) of rats after treatment of cisplatin and 1-PBG during both 0 - 24 h (respectively, from 1.57 g to 0.87 g; from 1.04 g to 0.11 g) and 0 - 72 h (respectively, from 2.98 g to 1.85 g; from 2.29 g to 0.35 g) periods. The fluorescence expression of CaM and 5-HT3R and expression of CaMKII, pCaMKII, ERK1/2 and pERK1/2 in the small intestine and brain of cisplatin- and 1-PBG-treated rats were remarkably suppressed by XBXT.Conclusions: The present study implies that inhibiting CaM/CaMKII/ERK1/2 signaling is an underlying mechanism of XBXT for treating CINV. These insights provide an experimental basis of XBXT for the clinical treatment of CINV.

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