Ascofuranone, an isoprenoid antibiotic, was originally isolated as a hypolipidemic substance from a culture broth of the phytopathogenic fungus, ascochlyta viciae. Adiponectin is mainly synthesized by adipocytes. It relieves insulin resistance by decreasing the plasma triglycerides and improving glucose uptake, and has anti-atherogenic properties. Here, we found that ascofuranone increases ...

Energy balance is maintained by a complex homeostatic system involving some signaling pathways and "nutrient sensors" in multiple tissues and organs. Any defect associated with the pathways can lead to metabolic disorders including obesity, type 2 diabetes, and the metabolic syndrome. The 5'-adenosine monophosphate-activated protein kinase (AMPK) and mammalian target ...

BACKGROUND: Obesity is associated with an increased incidence of left ventricular hypertrophy, diastolic dysfunction, heart failure, and premature cardiac aging. In the heart, intrinsic activation of the AMP-dependent protein kinase (AMPK) plays a pivotal role in the stress response to ischemia and hypertrophy. Furthermore, AMPK is an important regulator of ...

Improved glucose and lipid metabolism is a unique side effect of imatinib therapy in some chronic myeloid leukeamia (CML) patients. We recently reported that plasma levels of adiponectin, an important regulator of insulin sensitivity, are elevated following imatinib therapy in CML patients which could account for these improved metabolic outcomes. ...

Activation of mammalian target of rapamycin 1 (mTORC1) by nutrients, insulin and leptin leads to appetite suppression (anorexia). Contrastingly, increased AMP-activated protein kinase (AMPK) activity by ghrelin promotes appetite (orexia). However, the interplay between these mechanisms remains poorly defined. The relationship between the anorexigenic hormones, insulin and leptin, and the ...

To investigate the involvement of the nucleus accumbens (NAc) in cognitive impairment and the therapeutic effects of brain-derived neurotrophic factor (BDNF) in an animal model of cognitive deficit, we infused BDNF into the NAc of cognitively impaired aged rats. Cognition was evaluated by Morris water maze test. Structural synaptic plasticity ...

Focal adhesion kinase (FAK), a key regulator of cell adhesion and migration, is overexpressed in many types of cancer. The C-terminal focal adhesion targeting (FAT) domain of FAK is necessary for proper localization of FAK to focal adhesions and subsequent activation. Phosphorylation of Y926 in the FAT domain by the ...

Glucagon-like peptide-1 (GLP-1) and leptin are anorectic hormones produced in the small intestine and white adipose tissue, respectively. Investigating how these hormones act together as an integrated anorectic signal is important to elucidate a mechanism to maintain energy balance. In the present study, coadministration of subthreshold GLP-1 and leptin dramatically ...

OBJECTIVE: Adiponectin (APN) system malfunction is causatively related to increased cardiovascular morbidity/mortality in diabetic patients. The aim of the current study was to investigate molecular mechanisms responsible for APN transmembrane signaling and cardioprotection. METHODS AND RESULTS: Compared with wild-type mice, caveolin-3 knockout (Cav-3KO) mice exhibited modestly increased myocardial ischemia/reperfusion injury ...

Phosphorylation of histone H4 on one or both of its two histidine residues has been known to occur in liver cells for nearly 40 years and has been associated with proliferation of hepatocytes during regeneration of the liver following mechanical damage. More recently, large increases in histone H4 histidine kinase activity ...

Histone H3 is modified at serines 10 and 28 in interphase cells following activation of the RAS-MAPK or p38-MAPK pathways by growth factors or stress. These modifications are involved in the regulation of immediate-early genes, including Jun and Fos, whose increased expression is a trademark of various cancers. This review ...

Glycogen phosphorylase (GP) catalyzes the rate-limiting step in glycogen catabolism and plays a key role in maintaining cellular and organismal glucose homeostasis. GP is the first protein whose function was discovered to be regulated by reversible protein phosphorylation, which is controlled by phosphorylase kinase (PhK) and protein phosphatase 1 (PP1). Here ...

eNOS activation resulting in mitochondrial biogenesis is believed to play a central role in life span extension promoted by calorie restriction (CR). We investigated the mechanism of this activation by treating vascular cells with serum from CR rats and found increased Akt and eNOS phosphorylation, in addition to enhanced nitrite ...

Leptin exerts its action by binding to and activating the long form of leptin receptors (LEPRb). LEPRb activates JAK2 that subsequently phosphorylates and activates STAT3. The JAK2/STAT3 pathway is required for leptin control of energy balance and body weight. Defects in leptin signaling lead to leptin resistance, a primary risk ...

Adipose-derived stem cells (ASCs) are of great interest for the development of novel cell therapies due to their ease of isolation and expansion, immunosuppressive activity and multilineage differentiation potential. However, the mechanisms underlying the therapeutic potential of ASCs remain to be elucidated. Others and we have shown that nuclear proteins ...

Lim domain only protein 2 (Lmo2) is a transcription factor that plays a critical role in the development of T-acute lymphoblastic leukemia (T-ALL). A previous report established a link between Lmo2 expression and the nuclear presence of oncogenic Janus kinase 2 (JAK2), a non-receptor protein tyrosine kinase. The oncogenic JAK2 ...

Cell motility and adhesion involves dynamic microtubule (MT) acetylation/deacetylation, a process regulated by enzymes as HDAC6, a major cytoplasmic α-tubulin deacetylase. We identify G protein-coupled receptor kinase 2 (GRK2) as a key novel stimulator of HDAC6. GRK2, which levels inversely correlate with the extent of α-tubulin acetylation in epithelial cells ...

VRK1-mediated phosphorylation of histone H3 should be restricted in mitosis for faithful cell cycling, and defects in this process trigger cellular catastrophe. However, an interphasic regulator against VRK1 has not been actually investigated so far. Here, we show that a histone variant macro domain-containing histone H2A1.2 functions as a suppressor ...

Methylation of lysine 36 on histone H3 (H3K36) is catalyzed by the Set2 methyltransferase and is linked to transcriptional regulation. Previous studies have shown that trimethylation of H3K36 by Set2 is directed through its association with the phosphorylated repeats of the RNA polymerase C-terminal domain (RNAPII CTD). Here we show ...

A levan-type exopolysaccharide (EPS) from Paenibacillus polymyxa EJS-3 was successfully acetylated, phosphorylated and benzylated, respectively, affording its derivatives of acetylated levan (AL), phosphorylated levan (PL) and benzylated levan (BL). Then, the antioxidant and antitumor activities in vitro of the natural polysaccharide and its derivatives were determined. As results, AL, BL ...

Background:We examine the potential value of a series of clinically relevant PI3K-mTOR inhibitors alone, or in combination with histone deacetylase inhibitors, in a model of head and neck squamous cell carcinoma (HNSCC).Methods:Head and neck squamous cell carcinoma cell lines, human keratinocyte and HNSCC xenograft models were treated with histone deacetylase ...

Histone acetylation via CBP/p300 coordinates the expression of proinflammatory cytokines in the activation phase of inflammation, particularly through mitogen-activated protein kinases (MAPKs), nuclear factor-κB (NF-κB), and signal transducers and activators of transcription pathways. In contrast, histone deacetylases (HDACs) and protein phosphatases are mainly involved in the attenuation phase of inflammation. ...

The serine/threonine protein kinase Akt is a critical regulator of cell growth and survival in response to growth factors. A key step in Akt activation is phosphorylation at S473 by the mammalian target of rapamycin (mTOR) complex 2 (mTORC2). Although Rictor is required for the stability and activity of mTORC2, ...

Histone deacetylase (HDAC) inhibition plays a crucial role in mediating cardiogenesis and myocardial protection, whereas HDAC degradation has recently attracted attention in mediating the biological function of HDACs. However, it remains unknown whether HDAC inhibition modulates cardiogenesis and embryonic stem cell (ESC) survival through the proteasome pathway. Using the well-established ...

BCR-ABL1 kinase-positive leukemia cells accumulate high numbers of DNA double-strand breaks (DSBs) induced by the reactive oxygen species (ROS) or cytotoxic agents. To repair these lesions and prevent apoptosis BCR-ABL1 kinase stimulates the efficiency of DSB repair in leukemia cells. Histone acetylation-dependent chromatin re-modeling plays a crucial role in this ...

Although discovered long ago, post-translational phosphorylation of histones has been in the spotlight only recently. Information is accumulating almost daily on how histones are phosphorylated and their roles in cellular physiology and human diseases. An extensive crosstalk exists between phosphorylation and other post-translational modifications, which together regulate various biological processes ...

Exposure of yeast to high osmolarity induces a transient activation of the Hog1 stress-activated protein kinase (SAPK), which is required for cell survival under these conditions. However, sustained activation of the SAPK results in a severe growth defect. We found that prolonged SAPK activation leads to cell death, which is ...

Tumor associated macrophages (TAM) are severely compromised for the induction of proinflammatory mediators following TLR activation. Here, we reported that the defective toll like receptors (TLR) response in TAM was due to the malfunctioning of the myeloid differentiation primary response gene 88 (MyD88) dependent signaling cascade in concert with down ...

Acetylation of histone and nonhistone proteins is an important posttranslational modification affecting many cellular processes. Here, we report that NuA4 acetylation of Sip2, a regulatory β subunit of the Snf1 complex (yeast AMP-activated protein kinase), decreases as cells age. Sip2 acetylation, controlled by antagonizing NuA4 acetyltransferase and Rpd3 deacetylase, enhances ...

While lysine acetylation in the nucleus is well characterized, comparatively little is known about its significance in cytoplasmic signaling. Here we show that inhibition of the Sirt1 deacetylase, which is primarily cytoplasmic in cancer cell lines, sensitizes these cells to caspase-2-dependent death. To identify relevant Sirt1 substrates, we developed a ...

BACKGROUND: Histone deacetylase (HDAC) inhibitors have emerged as a new class of antitumor agents because they were demonstrated to induce cell cycle arrest, promote cell apoptosis, and inhibit metastasis. Recently, HDAC inhibitors were also shown to exhibit pronounced anti-inflammatory properties. However, the underlying mechanism contributing to the suppression of inflammatory ...

Global histone H1 phosphorylation correlates with cell cycle progression. However, the function of site-specific H1 variant phosphorylation remains unclear. Our mass spectrometry analysis revealed a novel N-terminal phosphorylation of the major H1 variant H1.4 at serine 35 (H1.4S35ph) which accumulates at mitosis immediately after H3 phosphorylation at serine 10. Protein ...

Post-translational modifications of RelA play an important role in regulation of NF-κB activation. We previously demonstrated that in malignant hematopoietic cells, histone deacetylase inhibitors (HDACIs) induced RelA hyperacetylation and NF-κB activation, attenuating lethality. We now present evidence that IκB kinase (IKK) β-mediated RelA Ser-536 phosphorylation plays a significant functional role ...

Oxidative stress and inflammation as the pathological components of Alzheimer's disease (AD) have been well understood. Among a diversity of mitogen-activated protein kinase (MAPK) family members, JNK and p38 MAPK subfamilies are relevant to the response of environmental stress, inflammatory stimuli, or other insults. Recent studies have demonstrated that epigenetic ...

Phosphorylation of heat shock protein 20 (Hsp20) by protein kinase A (PKA) is now recognised as an important regulatory mechanism modulating contractile activity in the human myometrium. Thus agonists that stimulate cyclic AMP production may cause relaxation with resultant beneficial effects on pathologies that affect this tissue such as the ...

The approval of histone deacetylase inhibitors for treatment of lymphoma subtypes has positioned histone modifications as potential targets for the development of new classes of anticancer drugs. Histones also undergo phosphorylation events, and Haspin is a protein kinase the only known target of which is phosphorylation of histone H3 at ...

Triptolide, a diterpene triepoxide, from the Chinese herb Tripterygium wilfordii Hook.f, exerts its anti-inflammatory and immunosuppressive activities by inhibiting the transcription factor nuclear factor-κB (NF-κB) pathway, through a mechanism not yet fully understood. We found that triptolide, in nanomolar concentrations, suppressed both constitutive and inducible NF-κB activation, but did not ...

ATF5 has been shown to be a critical regulator of cell proliferation and survival; however, the underlying mechanism remains largely unknown. We demonstrate here that ATF5 interacts with the transcriptional coactivator p300, which acetylates ATF5 at lysine-29 (K29), which in turn enhances the interaction between ATF5 and p300 and binding ...

The E3 ubiquitin-protein ligase Chfr is a mitotic stress checkpoint protein that delays mitotic entry in response to microtubule damage; however, the molecular mechanism by which Chfr accomplishes this remains elusive. Here, we show that Chfr levels are elevated in response to microtubule-damaging stress. Moreover, G(2)/M transition is associated with ...

Post-translational histone modifications regulate many aspects of chromosome activity. Threonine 3 of histone H3 is highly conserved, but the significance of its phosphorylation is unclear, and the identity of the corresponding kinase in plants is unknown. Therefore, we characterized the candidate kinase in Arabidopsis thaliana, called AtHaspin. Recombinant AtHaspin in ...

Environmental neurotoxic exposure to agrochemicals has been implicated in the etiopathogenesis of Parkinson's disease (PD). The widely used herbicide paraquat is among the few environmental chemicals potentially linked with PD. Since epigenetic changes are beginning to emerge as key mechanisms in neurodegenerative diseases, herein we examined the effects of paraquat ...

In this issue of Molecular Cell, Wu et al. (2011) reveal that ubiquitylation of histone 2B lysine 34 stimulates histone methyltransferase activity on nucleosomes, a finding with implications for the general mechanism by which monoubiquitylation may influence subsequent modification activities.

The best characterized examples of crosstalk between two or more different post-translational modifications (PTMs) occur with respect to histones. These examples demonstrate the critical roles that crosstalk plays in regulating cell signaling pathways. Recently, however, non-histone crosstalk has been observed between serine/threonine phosphorylation and the modification of arginine and lysine ...

Histone H3 variant H3.3, while differing from canonical H3 (H3.1) by only five amino acids, is assembled into nucleosomes, along with histone H4, at genic regions by the histone chaperone HIRA, whereas H3.1 is assembled into nucleosomes in a CAF-1-dependent reaction. Here, we show that phosphorylation of histone H4 Ser ...

Airway smooth muscle cells (ASMC) secrete eotaxin and RANTES in response to TNF-α, which was inhibited by the NF-ΚB inhibitor dimethylfumarate (DMF). NF-ΚB/IΚB glutathionylation and changes in chromatin remodelling can inhibit NF-ΚB activity. In this study, we determined whether NF-ΚB/IΚB glutathionylation and reduced histone H3 phosphorylation might underlie DMF's inhibitory ...

Despite the importance of cyclin-Cdk related kinases (CRK) in regulation of cell and life cycle of kinetoplastida parasites, only limited knowledge about their substrates are presently available. Here, the potential substrates were searched for an S-phase LdCyc1-CRK3 complex from Leishmania donovani based on the presence of Cdk target phosphorylation site ...

In the present study, the dual effects of phloretin and phloridzin on the methylglyoxal (MGO)-induced glycation were investigated in three Nα-acetyl amino acids (arginine, cysteine and lysine) models and three N-terminal polypeptides (PP01, PP02 and PP03 contain arginine, cysteine and lysine, respectively) models. In both Nα-acetyl amino acids and N-terminal ...

Histone deacetylases (HDACs) are aberrantly expressed, and inhibitors of HDACs induce apoptosis in lymphoplasmacytic cells (LPCs) in Waldenström macroglobulinemia (WM). The molecular profile by which these agents induce apoptosis in WM LPCs remains to be delineated. We examined the activity of the histone deacetylase inhibitor, vorinostat, and dissected its pro-apoptotic ...

The H3K27 histone methyltransferase, Ezh2 (enhancer of zeste 2) is a Polycomb group protein that plays important roles in many biological processes including cellular differentiation, stem cell biology, and cancer development. Upregulation of Ezh2 is observed in various human cancers consistent with its role in cell proliferation. Thus, understanding the ...

Various types of post-translational modifications (PTMs) of the histone tails have been revealed, but a few have been found within the histone core sequences. Histone core PTMs have the potential to modulate nucleosome structure and DNA accessibility. Here, we studied the histone H2B core domain and found that phosphorylation of ...