scholarly journals Clocking In Time to Gate Memory Processes: The Circadian Clock Is Part of the Ins and Outs of Memory

2018 ◽  
Vol 2018 ◽  
pp. 1-11 ◽  
Author(s):  
Oliver Rawashdeh ◽  
Rex Parsons ◽  
Erik Maronde
Keyword(s):  
Protein Kinase ◽  
Posttranslational Modifications ◽  
Clock Gene ◽  
De Novo ◽  
Memory Performance ◽  
Cyclic Adenosine Monophosphate ◽  
Adenosine Monophosphate ◽  
Mitogen Activated Protein Kinase ◽  
Long Term Memory ◽  
Tightly Coupled

Learning, memory consolidation, and retrieval are processes known to be modulated by the circadian (circa: about; dies: day) system. The circadian regulation of memory performance is evolutionarily conserved, independent of the type and complexity of the learning paradigm tested, and not specific to crepuscular, nocturnal, or diurnal organisms. In mammals, long-term memory (LTM) formation is tightly coupled to de novo gene expression of plasticity-related proteins and posttranslational modifications and relies on intact cAMP/protein kinase A (PKA)/protein kinase C (PKC)/mitogen-activated protein kinase (MAPK)/cyclic adenosine monophosphate response element-binding protein (CREB) signaling. These memory-essential signaling components cycle rhythmically in the hippocampus across the day and night and are clearly molded by an intricate interplay between the circadian system and memory. Important components of the circadian timing mechanism and its plasticity are members of the Period clock gene family (Per1, Per2). Interestingly, Per1 is rhythmically expressed in mouse hippocampus. Observations suggest important and largely unexplored roles of the clock gene protein PER1 in synaptic plasticity and in the daytime-dependent modulation of learning and memory. Here, we review the latest findings on the role of the clock gene Period 1 (Per1) as a candidate molecular and mechanistic blueprint for gating the daytime dependency of memory processing.

Protein kinase Cζ mediated Raf-1/extracellular-regulated kinase activation by daunorubicin

Blood ◽  
2003 ◽  
Vol 101 (4) ◽  
pp. 1543-1550 ◽  
Author(s):  
Véronique Mansat-De Mas ◽  
Hélène Hernandez ◽  
Isabelle Plo ◽  
Christine Bezombes ◽  
Nicolas Maestre ◽  
...  
Keyword(s):  
Protein Kinase ◽  
Mapk Pathway ◽  
Cyclic Adenosine Monophosphate ◽  
Adenosine Monophosphate ◽  
Mek Inhibitor ◽  
Mapk Signaling ◽  
Mitogen Activated Protein Kinase ◽  
Protective Function ◽  
Erk Phosphorylation ◽  
Extracellular Regulated Kinase

In light of the emerging concept of a protective function of the mitogen-activated protein kinase (MAPK) pathway under stress conditions, we investigated the influence of the anthracycline daunorubicin (DNR) on MAPK signaling and its possible contribution to DNR-induced cytotoxicity. We show that DNR increased phosphorylation of extracellular-regulated kinases (ERKs) and stimulated activities of both Raf-1 and extracellular-regulated kinase 1 (ERK1) within 10 to 30 minutes in U937 cells. ERK1 stimulation was completely blocked by either the mitogen-induced extracellular kinase (MEK) inhibitor PD98059 or the Raf-1 inhibitor 8-bromo-cAMP (cyclic adenosine monophosphate). However, only partial inhibition of Raf-1 and ERK1 stimulation was observed with the antioxidant N-acetylcysteine (N-Ac). Moreover, the xanthogenate compound D609 that inhibits DNR-induced phosphatidylcholine (PC) hydrolysis and subsequent diacylglycerol (DAG) production, as well as wortmannin that blocks phosphoinositide-3 kinase (PI3K) stimulation, only partially inhibited Raf-1 and ERK1 stimulation. We also observed that DNR stimulated protein kinase C ζ (PKCζ), an atypical PKC isoform, and that both D609 and wortmannin significantly inhibited DNR-triggered PKCζ activation. Finally, we found that the expression of PKCζ kinase-defective mutant resulted in the abrogation of DNR-induced ERK phosphorylation. Altogether, these results demonstrate that DNR activates the classical Raf-1/MEK/ERK pathway and that Raf-1 activation is mediated through complex signaling pathways that involve at least 2 contributors: PC-derived DAG and PI3K products that converge toward PKCζ. Moreover, we show that both Raf-1 and MEK inhibitors, as well as PKCζ inhibition, sensitized cells to DNR-induced cytotoxicity.

scholarly journals A sperm peptide enhances long-term memory in female Drosophila

2019 ◽  
Vol 5 (11) ◽  
pp. eaax3432 ◽  
Author(s):  
L. Scheunemann ◽  
A. Lampin-Saint-Amaux ◽  
J. Schor ◽  
T. Preat
Keyword(s):  
Memory Performance ◽  
Cyclic Adenosine Monophosphate ◽  
Adenosine Monophosphate ◽  
Long Term Memory ◽  
Single Pair ◽  
Term Memory ◽  
Dietary Preference ◽  
Sex Peptide

Can mating influence cognitive functions such as learning and memory in a permanent way? We have addressed this question using a combined behavioral and in vivo imaging approach, finding that aversive long-term memory performance strongly increases in Drosophila females in response to sperm transfer following mating. A peptide in the male sperm, the sex peptide, is known to cause marked changes in female reproductive behavior, as well as other behaviors such as dietary preference. Here, we demonstrate that this sex peptide enhances memory by acting on a single pair of serotonergic brain neurons, in which activation of the sex peptide receptor stimulates the cyclic adenosine monophosphate/protein kinase A pathway. We thus reveal a strong effect of mating on memory via the neuromodulatory action of a sperm peptide on the female brain.

scholarly journals The Anti-Melanogenesis Effect of 3,4-Dihydroxybenzalacetone through Downregulation of Melanosome Maturation and Transportation in B16F10 and Human Epidermal Melanocytes

2021 ◽  
Vol 22 (6) ◽  
pp. 2823
Author(s):  
Yi-Jung Liu ◽  
Jia-Ling Lyu ◽  
Yueh-Hsiung Kuo ◽  
Chen-Yuan Chiu ◽  
Kuo-Chiang Wen ◽  
...  
Keyword(s):  
Protein Kinase ◽  
Glycogen Synthase ◽  
Radical Scavenging ◽  
Reducing Power ◽  
Cyclic Adenosine Monophosphate ◽  
Adenosine Monophosphate ◽  
Mitogen Activated Protein Kinase ◽  
Related Protein ◽  
Mitogen Activated Protein ◽  
Tyrosinase Related Protein

The biosynthesis pathway of melanin is a series of oxidative reactions that are catalyzed by melanin-related proteins, including tyrosinase (TYR), tyrosinase-related protein-1 (TRP-1), and tyrosinase-related protein-2 (TRP-2). Reagents or materials with antioxidative or free radical-scavenging activities may be candidates for anti-melanogenesis. 3,4-Dihydroxybenzalacetone (DBL) is a polyphenol isolated from fungi, such as Phellinus obliguus (Persoon) Pilat and P. linteus. In this study, we investigated the effects and mechanisms of DBL on antioxidation and melanogenesis in murine melanoma cells (B16F10) and human epidermal melanocytes (HEMs). The results indicated that DBL scavenged 2,2-diphenyl-1-picrylhydrazyl (DPPH) and hydroxyl radicals, and exhibited potent reducing power, indicating that it displays strong antioxidative activity. DBL also inhibited the expression of TYR, TRP-1, TRP-2, and microphthalmia-related transcription factor (MITF) in both the cells. In addition, DBL inhibited hyperpigmentation in B16F10 and HEMs by regulating the cyclic adenosine monophosphate (cAMP)/protein kinase A (PKA), v-akt murine thymoma viral oncogene homolog (AKT)/glycogen synthase kinase 3 beta (GSK3β), and mitogen-activated protein kinase kinase (MEK)/extracellular regulated protein kinase (ERK) signaling pathways. DBL not only shortened dendritic melanocytes but also inhibited premelanosome protein 17 (PMEL17) expression, slowing down the maturation of melanosome transportation. These results indicated that DBL promotes anti-melanogenesis by inhibiting the transportation of melanosomes. Therefore, DBL is a potent antioxidant and depigmenting agent that may be used in whitening cosmetics.

scholarly journals A yeast MAPK cascade regulates pexophagy but not other autophagy pathways

2010 ◽  
Vol 189 (2) ◽  
pp. 303-310 ◽  
Author(s):  
Ravi Manjithaya ◽  
Shveta Jain ◽  
Jean-Claude Farré ◽  
Suresh Subramani
Keyword(s):  
Protein Kinase ◽  
Mapk Pathway ◽  
Signal Transduction Pathway ◽  
Cyclic Adenosine Monophosphate ◽  
Adenosine Monophosphate ◽  
Mapk Cascade ◽  
Mitogen Activated Protein Kinase ◽  
Mitogen Activated Protein ◽  
Simultaneous Activation ◽  
Cellular Components

Autophagy is important for many cellular processes such as innate immunity, neurodegeneration, aging, and cancer. Although the signaling events triggering autophagy have been studied, little is known regarding the signaling mechanisms by which autophagy is redirected to achieve selective removal of cellular components. We have used the degradation of a peroxisomal marker to investigate the role of protein kinases in selective autophagy of peroxisomes (pexophagy) in Saccharomyces cerevisiae. We show that the Slt2p mitogen-activated protein kinase (MAPK) and several upstream components of its signal transduction pathway are necessary for pexophagy but not for pexophagosome formation or other nonselective and selective forms of autophagy. Other extracellular signals that activate this pathway do not trigger pexophagy on their own, suggesting that this MAPK cascade is necessary but not sufficient to trigger pexophagy. We propose that pexophagy requires the simultaneous activation of this MAPK pathway and a hexose-sensing mechanism acting through protein kinase A and cyclic adenosine monophosphate.

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