pinecone/core-2020-05-10-deduplication huggingface dataset:
Regulation of nicotinic acetylcholine receptors by tyrosine kinases in the peripheral and central nervous system: same players, different roles

Nicotinic acetylcholine receptors (nAChRs) exist in many subtypes and are found in the peripheral and central nervous system where they mediate or modulate synaptic transmission. We review how tyrosine phosphorylation and kinases regulate muscle and neuronal nAChRs. Interestingly, although some of the same kinase players interact with the various receptor subtypes, the functional consequences are different. While concerted action of MuSK, Abl- and Src-family kinases (SFKs) regulates the synaptic distribution of nAChRs at the neuromuscular junction, SFKs activate heteromeric neuronal nAChRs in adrenal chromaffin cells, thereby enhancing catecholamine secretion. In contrast, the activity of homomeric neuronal nAChRs, as found in the hippocampus, is negatively regulated by tyrosine phosphorylation and SFKs. It appears that tyrosine kinases provide the means to regulate all nAChRs; but the functional consequences, even those caused by the same kinase family, are specific for each receptor subtype and location
Betaine homocysteine S-methyltransferase: just a regulator of homocysteine metabolism?

El pdf del artículo es la versión de autor.Betaine homocysteine methyltransferase (BHMT), a Zn2+-dependent thiolmethyltransferase, contributes to the regulation of homocysteine levels, whose increases are considered a risk factor for cardiovascular diseases. Most plasma homocysteine is generated through the liver methionine cycle, in which BHMT metabolizes approximately 25% of this non-protein amino acid. This process allows recovery of one of the three methylation equivalents used in phosphatidylcholine synthesis through transmethylation, a major homocysteine producing pathway. Although BHMT has been known for over 40 years the difficulties encountered in its isolation precluded detailed studies until very recently. Thus, the last 10 years, since the sequence became available, have yielded extensive structural and functional data. Moreover, recent findings offer clues for potential new functions for BHMT. The purpose of this review is to provide an integrated view of the knowledge available on BHMT, and to analyze its putative roles in other processes through interactions undercover to date.Ministerio de Educación y Ciencia (PM 97/0064, BMC 2002-0243 and BFU 2005-00050 to M.A.P. and SAF 2003-03713 to D.P-S.) and Fondo de Investigación Sanitaria (FIS 01/1077 and RCMN C03/08 to M.A.P.Peer reviewe
Monothiol glutaredoxins: a common domain for multiple functions

Monothiol glutaredoxins with the CGFS sequence at the active site are widespread among prokaryotes and eukaryotes. Two subclasses exist, those with a single glutaredoxin domain and those with a thioredoxin-like region followed by one or
more glutaredoxin domains. Studies in Saccharomyces cerevisiae have demonstrated the role of the Grx5 protein in the biogenesis of iron-sulphur clusters. Grx5 homologues in other eukaryotes could carry out similar functions. Two S. cerevisiae monothiol glutaredoxins with the thioredoxin-like extension, Grx3 and Grx4, are modulators of the transcriptional activator Aft1, which regulates iron uptake in yeast. The human PICOT protein is a Grx3/Grx4 homologue with the same hybrid primary structure, which regulates protein kinase C activity and may participate in physiological processes such as control of cardiac function. Therefore, monothiol glutaredoxins share a common basic structural motif and biochemical mechanism of action, while participating in a diversity of cellular functions as protein redox regulators
Glycogen synthase 2 is a novel target gene of peroxisome proliferator-activated receptors.

Glycogen synthase 2 (Gys-2) is the ratelimiting enzyme in the storage of glycogen in liver and adipose tissue, yet little is known about regulation of Gys-2 transcription. The peroxisome proliferator-activated receptors (PPARs) are transcription factors involved in the regulation of lipid and glucose metabolism and might be hypothesized to govern glycogen synthesis as well. Here, we show that Gys-2 is a direct target gene of PPARalpha, PPARbeta/delta and PPARgamma. Expression of Gys-2 is significantly reduced in adipose tissue of PPARalpha-/-, PPARbeta/delta-/- and PPARgamma+/- mice. Furthermore, synthetic PPARbeta/delta, and gamma agonists markedly up-regulate Gys-2 mRNA and protein expression in mouse 3T3-L1 adipocytes. In liver, PPARalpha deletion leads to decreased glycogen levels in the refed state, which is paralleled by decreased expression of Gys-2 in fasted and refed state. Two putative PPAR response elements (PPREs) were identified in the mouse Gys-2 gene: one in the upstream promoter (DR-1prom) and one in intron 1 (DR-1int). It is shown that DR-1int is the response element for PPARs, while DR-1prom is the response element for Hepatic Nuclear Factor 4 alpha (HNF4alpha). In adipose tissue, which does not express HNF4alpha, DR-1prom is occupied by PPARbeta/delta and PPARgamma, yet binding does not translate into transcriptional activation of Gys-2. Overall, we conclude that mouse Gys-2 is a novel PPAR target gene and that transactivation by PPARs and HNF4alpha is mediated by two distinct response elements
A new synthesis in epigenetics: towards an unified function of DNA methylation from invertebrates to vertebrates

DNA methylation is generally limited to CpG doublets located at gene promoter with an involvement in gene silencing. Surprisingly, two recent papers showed an extensive methylation affecting coding portions of transcriptionally active genes in human and plants prompting a rethink of DNA methylation in eukaryotes. Actually, gene body methylation is not surprising since it was repeatedly reported in invertebrates, where it interferes with transcriptional elongation preventing aberrant transcription initiations. As a whole, data published suggest that the most ancestral function of DNA methylation is the control of genes that are susceptible to transcriptional interference and not to gene silencing. The recruitment of DNA methylation for silencing represents a successive tinkered use. In view of this additional function, invertebrate-vertebrates transition has been accompanied by new constrains on DNA methylation that resulted in the strong conservation of the DNA methylation machinery in vertebrates and in the non-viability of mutants lacking DNA methylation
Pharmacological manipulation of L-carnitine transport into L6 cells with stable overexpression of human OCTN2

The high-affinity Na+-dependent carnitine transporter OCTN2 (SLC22A5) has a high renal expression and reabsorbs most filtered carnitine. To gain more insight into substrate specificity of OCTN2, we overexpressed hOCTN2 in L6 cells and characterized the structural requirements of substances acting as human OCTN2 (hOCTN2) inhibitors. A 1905-bp fragment containing the hOCTN2 complete coding sequence was introduced into the pWpiresGFP vector, and L6 cells were stably transduced using a lentiviral system. The transduced L6 cells revealed increased expression of hOCTN2 on the mRNA, protein and functional levels. Structural requirements for hOCTN2 inhibition were predicted in silico and investigated in vitro. Essential structural requirements for OCTN2 inhibition include a constantly positively charged nitrogen atom and a carboxyl, nitrile or ester group connected by a 2-4-atom linker. Our cell system is suitable for studying in vitro interactions with OCTN2, which can subsequently be investigated in vivo
p63 in epithelial development.

This is the author's final draft of the paper published as Cellular and Molecular Life Sciences, 2008, 65 (20), pp. 3126-3133.  The original publication is available at www.springerlink.com.  Doi: 10.1007/s00018-008-8119-xThe epidermis, the outer layer of the skin composed of keratinocytes, is a stratified epithelium that functions as a barrier to protect the organism from dehydration and external insults. The epidermis develops following the action of the transcription factor p63, amember of the p53 family of transcription factors. The Trp63 gene contains two promoters driving the production of distinct proteins, one with an N-terminal transactivation domain (TAp63) and one without (ΔNp63), although their relative contribution to epidermal development is not clearly established. Trp63 mutations are involved in the pathogenesis of several human diseases, phenotypically characterized by ectodermal dysplasia. In this review, we summarize the current advances that have been made in understanding the role of p63 in epidermal morphogenesis
Olfactory ensheathing cells are attracted to, and can endocytose, bacteria

Olfactory ensheathing cells (OECs) have been shown previously to express Toll-like receptors and to respond to bacteria by translocating nuclear factor-kB from the cytoplasm to the nucleus. In this study,we show that OECs extended significantly more pseudopodia when they were exposed to Escherichia coli than in the absence of bacteria (p=0.019). Coimmunoprecipitation showed that E. coli binding to OECs was mediated by Toll-like receptor 4. Lyso-\ud
Tracker, a fluorescent probe that accumulates selectively\ud
in lysosomes, and staining for type 1 lysosomeassociated\ud
membrane proteins demonstrated that endocytosed FITC-conjugated E. coli were translocated to lysosomes. They appeared to be subsequently broken down, as shown by transmission electron microscopy. No obvious adherence to the membrane and less phagocytosis was observed when\ud
OECs were incubated with inert fluorescent microspheres.\ud
The ability of OECs to endocytose bacteria supports the notion that OECs play an innate immune function by protecting olfactory tissues from bacterial infection
Early effects of copper accumulation on methionine metabolism

El pdf del artículo es la versión de autor.Wilson’s disease is characterized by long-term hepatic accumulation of copper leading to liver disease with reduction of S-adenosylmethionine synthesis. However, the initial changes in this pathway remain unknown and constitute the objective of the present study. Using the Long Evans Cinnamon rat model early alterations in the mRNA and protein levels, as well as in the activities of several enzymes of the methionine cycle were detected. Noteworthy, the main change was a redox mediated 80% decrease in the mRNA levels of the methionine adenosyltransferase regulatory subunit as compared to the control group. Moreover, changes in S-adenosylmethionine, S-adenosylhomocysteine, methionine and glutathione levels were also observed. In addition, in vitro experiments show that copper affects the activity and folding of methionine adenosyltransferase catalytic subunits. Taken together, these observations indicate that early copper accumulation alters methionine metabolism with a pattern distinct from that described previously for other liver diseases.Ministerio de Educación y Ciencia (BMC2002-00243 and BFU2005-00050 to M.A.P. and SAF2006-03489 to D.P-S.) and the Fondo de Investigación Sanitaria del Instituto de Salud Carlos III (RCMN C03/08 to M.A.P.). M. D. was supported by fellowships of the RCMN C03/08 and PI05/0563 grants of the Fondo de Investigación Sanitaria del Instituto de Salud Carlos III.Peer reviewe
Structure-function relationships in methionine adenosyltransferases

El pdf del artículo es la versión post-print.Methionine adenosyltransferases (MAT) are the family of enzymes that synthesize the main biological methyl donor, S-adenosylmethionine. The high sequence conservation among catalytic subunits from bacteria and Eukarya preserves key residues that control activity and oligomerization, which is reflected in the protein structure. However, structural differences among complexes with substrates and products have led to proposals of several reaction mechanisms. In parallel, folding studies are starting to explain how the three intertwined domains of the catalytic subunit are produced, and the importance of certain intermediates in attaining the active final conformation. This review analyzes the available structural data and proposes a consensus interpretation that facilitates an understanding of the pathological problems derived from impairment of MAT function. In addition, new research opportunities directed toward clarification of aspects that remain obscure are also identified.Ministerio de Educación y Ciencia (BMC2002-00243 and BFU2005-00050 to M.A.P.), the Fondo de Investigación Sanitaria del Instituto de Salud Carlos III (RCMN C03/08 to M.A.P.), the National Institutes of Health (GM31186 to G.D.M. and CA06927 to FCCC) and an appropriation from the Commonwealth of Pennsylvania.Peer reviewe
Hydroxylation of demethoxy-Q6 constitutes a control point in yeast coenzyme Q6 biosynthesis

23 páginas, 8 figuras, 2 tablas.Coenzyme Q is a lipid molecule required for respiration and antioxidant protection. Q biosynthesis in Saccharomyces cerevisiae requires nine proteins (Coq1p–Coq9p). We demonstrate in this study that Q levels are modulated during growth by its conversion from demethoxy-Q (DMQ), a late intermediate. Similar conversion was produced when cells were subjected to oxidative stress conditions. Changes in Q6/DMQ6 ratio were accompanied by changes in COQ7 gene mRNA levels encoding the protein responsible for the DMQ hydroxylation, the penultimate step in Q biosynthesis pathway. Yeast coq null mutant failed to accumulate any Q late biosynthetic intermediate. However, in coq7 mutants the addition of exogenous Q produces the DMQ synthesis. Similar effect was produced by over-expressing ABC1/COQ8. These results support the existence of a biosynthetic complex that allows the DMQ6 accumulation and suggest that Coq7p is a control point for the Q biosynthesis regulation in yeast.The work was supported by the Spanish Ministerio de Ciencia y Tecnología, Grant BFU2005–03017/BMC, and by NIH GM45952 to CFC.Peer reviewe
PAP1 signaling involves MAPK signal transduction

El pdf del artículo es la versión post-print.-- et al.Pancreatitis-associated protein 1 (PAP1) belongs to the Reg family of secretory proteins. Several important biological roles have been attributed to PAP1 but the signaling pathways activated by this protein remain only partially understood. Here, we describe the intracellular pathways triggered by PAP1 in a pancreatic acinar cell line. Taking advantage of the fact that PAP1 induces its own transcription, we performed ChIP assays to analyze the recruitment of transcriptional factors on its promoter. Our results show that PAP1 increased the transactivation activity of pap1 and the binding on its promoter of the nuclear factors C/EBPβ, P-CREB, P-ELK1, EGR1, STAT3, and ETS2, which are downstream targets of MAPK signaling. p44/42, p38, and JNK MAPKs activity increased after PAP1 treatment. In addition, pharmacological inhibition of these kinases markedly inhibited the induction of pap1 mRNA. Taken together, these results indicated that the mechanism of PAP1 action involves the activation of the MAPK superfamily.This work was supported by the FIS PI050599 and FIS PI081608 projects to E. Folch-Puy, Acción Integrada HF2006-0092 and CIBERehd to D. Closa and Spanish Ministry of Science and Technology BFU2007-63120 and CSD2006-49 to G. López-Rodas. CIBERehd is funded by the Instituto de Salud Carlos III. E. Folch-Puy is the recipient of a Ramón y Cajal contract from the Spanish Ministry of Education and Science. M. Ferrés-Masó is the recipient of a FIS-Instituto de Salud Carlos III contract PI050599.Peer reviewe
Alternative splicing of G protein-coupled receptors: physiology and pathophysiology

This is the author's final draft of the paper published as Cellular and Molecular Life Sciences, 2009, 66 (20), pp. 3337-3352.  The original publication is available at www.springerlink.com.  Doi: 10.1007/s00018-009-0093-4The G protein-coupled receptors (GPCRs) are a superfamily of transmembrane receptors that have a broad distribution and can collectively recognise a diverse array of ligands. Activation or inhibition of GPCR signalling can affect many (patho)physiological processes, and consequently they are a major target for existing and emerging drug therapies. A common observation has been that the pharmacological, signalling and regulatory properties of GPCRs can differ in a cell- and tissue-specific manner. Such “phenotypic” diversity might be attributable to post-translational modifications and/or association of GPCRs with accessory proteins, however, post-transcriptional mechanisms are also likely to contribute. Although approximately 50% of GPCR genes are intronless, those that possess introns can undergo alternative splicing, generating GPCR subtype isoforms that may differ in their pharmacological, signalling and regulatory properties. In this review we shall highlight recent research into GPCR splice variation and discuss the potential consequences this might have for GPCR function in health and disease
Contribution of hypoxia to Alzheimer's disease: is HIF-1alpha a mediator of neurodegeneration?

The mammalian brain is extremely sensitive to alterations in cellular homeostasis as a result of environmental or physiological insults. In particular, hypoxic/ischemic challenges (i.e. reduced oxygen and/or glucose delivery) cause severe and detrimental alterations in brain function and can trigger neuronal cell death within minutes. Unfortunately, as we age, oxygen delivery to cells and tissues is impaired, thereby increasing the susceptibility of neurons to damage. Thus, hypoxic (neuronal) adaptation is significantly compromised during aging. Many neurological diseases, such as stroke, Alzheimer's disease (AD), Parkinson's disease and diabetes, are characterized by hypoxia, a state that is believed to only exacerbate disease progression. However, the contribution of hypoxia and hypoxia-mediated pathways to neurodegeneration remains unclear. This review discusses current evidence on the contribution of oxygen deprivation to AD, with an emphasis on hypoxia inducible transcription factor-1 (HIF-1)-mediated pathways and the association of AD with the cytoskeleton regulator cyclin-dependent kinase 5. (Part of a multi-author review.)
Emerging concepts in acute mountain sickness and high-altitude cerebral edema: from the molecular to the morphological

Acute mountain sickness (AMS) is a neurological disorder that typically affects mountaineers who ascend to high altitude. The symptoms have traditionally been ascribed to intracranial hypertension caused by extracellular vasogenic edematous brain swelling subsequent to mechanical disruption of the blood-brain barrier in hypoxia. However, recent diffusion-weighted magnetic resonance imaging studies have identified mild astrocytic swelling caused by a net redistribution of fluid from the "hypoxia-primed" extracellular space to the intracellular space without any evidence for further barrier disruption or additional increment in brain edema, swelling or pressure. These findings and the observation of minor vasogenic edema present in individuals with and without AMS suggest that the symptoms are not explained by cerebral edema. This has led to a re-evaluation of the relevant pathogenic events with a specific focus on free radicals and their interaction with the trigeminovascular system. (Part of a multi-author review.)
RNA-seq: from technology to biology.

Next-generation sequencing technologies are now being exploited not only to analyse static genomes, but also dynamic transcriptomes in an approach termed RNA-seq. Although these powerful and rapidly evolving technologies have only been available for a couple of years, they are already making substantial contributions to our understanding of genome expression and regulation. Here, we briefly describe technical issues accompanying RNA-seq data generation and analysis, highlighting differences to array-based approaches. We then review recent biological insight gained from applying RNA-seq and related approaches to deeply sample transcriptomes in different cell types or physiological conditions. These approaches are providing fascinating information about transcriptional and post-transcriptional gene regulation, and they are also giving unique insight into the richness of transcript structures and processing on a global scale and at unprecedented resolution
Fatigue in neuromuscular disorders: Focus on Guillain-Barré syndrome and Pompe disease

Fatigue accounts for an important part of the burden experienced by patients with neuromuscular disorders. Substantial high prevalence rates of fatigue are reported in a wide range of neuromuscular disorders, such as Guillain-Barré syndrome and Pompe disease. Fatigue can be subdivided into experienced fatigue and physiological fatigue. Physiological fatigue in turn can be of central or peripheral origin. Peripheral fatigue is an important contributor to fatigue in neuromuscular disorders, but in reaction to neuromuscular disease fatigue of central origin can be an important protective mechanism to restrict further damage. In most cases, severity of fatigue seems to be related with disease severity, possibly with the exception of fatigue occurring in a monophasic disorder like Guillain-Barré syndrome. Treatment of fatigue in neuromuscular disease starts with symptomatic treatment of the underlying disease. When symptoms of fatigue persist, non-pharmacological interventions, such as exercise and cognitive behavioral therapy, can be initiated
Catestatin, an endogenous Chromogranin A-derived peptide, inhibits in vitro growth of Plasmodium falciparum

Catestatin, an endogenous peptide derived from
bovine chromogranin A, and its active domain cateslytin
display powerful antimicrobial activities. We have tested
the activities of catestatin and other related peptides on the
growth of Plasmodium falciparum in vitro. Catestatin
inhibits growth of the chloroquine-sensitive strain of
P. falciparum 3D7, exhibiting 88% inhibition at 20 lM.
A similar partial inhibition of parasite growth was observed
for the chloroquine-resistant strain, 7G8 (64%,) and the
multidrug-resistant strain, W2 (62%). In the presence of
parasite-specific lactate dehydrogenase, a specific protein–
protein interaction between catestatin and plasmepsin II
precursor was demonstrated. In addition, catestatin partially
inhibited the parasite-specific proteases plasmepsin in
vitro. A specific interaction between catestatin and
plasmepsins II and IV from P. falciparum and plasmepsin
IV from the three remaining species of Plasmodium known
to infect man was observed, suggesting a catestatininduced
reduction in availability of nutrients for protein
synthesis in the parasite
Cell-specific and lamin-dependent targeting of novel transmembrane proteins in the nuclear envelope.

Nuclear envelope complexity is expanding with respect to identification of protein components. Here we test the validity of proteomics results that identified 67 novel predicted nuclear envelope transmembrane proteins (NETs) from liver by directly comparing 30 as tagged fusions using targeting assays. This confirmed 21 as NETs, but 4 only targeted in certain cell types, underscoring the complexity of interactions that tether NETs to the nuclear envelope. Four NETs accumulated at the nuclear rim in normal fibroblasts but not in fibroblasts lacking lamin A, suggesting involvement of lamin A in tethering them in the nucleus. However, intriguingly, for the NETs tested alternative mechanisms for nuclear envelope retention could be found in Jurkat cells that normally lack lamin A. This study expands by a factor of three the number of liver NETs analyzed, bringing the total confirmed to 31, and shows that several have multiple mechanisms for nuclear envelope retention