Miracle-dz/UniFAR-FTUs huggingface dataset:
The SUMO1-E67 Interacting Loop Peptide Is an Allosteric Inhibitor of the Dipeptidyl Peptidases 8 and 9*

Background: SUMO1 binds to an arm motif in the prolyl-peptidase DPP9, leading to allosteric activation of the peptidase. Results: A SUMO1 peptide covering the DPP9 interaction surface inhibits DPP9 activity. Inhibition is dependent on residues in the DPP9 arm motif. Conclusion: The SUMO1 peptide and its variants are allosteric DPP9 inhibitors. Significance: This work highlights the potential use of peptides mimicking interaction surfaces for modulating enzyme activity. The intracellular peptidases dipeptidyl peptidase (DPP) 8 and DPP9 are involved in multiple cellular pathways including antigen maturation, cellular homeostasis, energy metabolism, and cell viability. Previously we showed that the small ubiquitin-like protein modifier SUMO1 interacts with an armlike structure in DPP9, leading to allosteric activation of the peptidase. Here we demonstrate that the E67-interacting loop (EIL) peptide, which corresponds to the interaction surface of SUMO1 with DPP9, acts as a noncompetitive inhibitor of DPP9. Moreover, by analyzing the sensitivity of DPP9 arm mutants to the EIL peptide, we mapped specific residues in the arm that are important for inhibition by the EIL, suggesting that the peptide acts as an allosteric inhibitor of DPP9. By modifying the EIL peptide, we constructed peptide variants with more than a 1,000-fold selectivity toward DPP8 (147 nm) and DPP9 (170 nm) over DPPIV (200 μm). Furthermore, application of these peptides to cells leads to a clear inhibition of cellular prolyl peptidase activity. Importantly, in line with previous publications, inhibition of DPP9 with these novel allosteric peptide inhibitors leads to an increase in EGF-mediated phosphorylation of Akt. This work highlights the potential use of peptides that mimic interaction surfaces for modulating enzyme activity.
Patchy stomatal behavior during midday depression of leaf CO₂ exchange in tropical trees.

We investigated effects of heterogeneous stomatal behavior on diurnal patterns of leaf gas exchange in 10 tree species. Observations were made in middle and upper canopy layers of potted tropical rainforest trees in a nursery at the Forest Research Institute Malaysia. Measurements were taken from 29 January to 3 February 2010. We measured in situ diurnal changes in net photosynthetic rate and stomatal conductance in three leaves of each species under natural light. In both top-canopy and sub-canopy species, midday depression of net assimilation rate occurred in late morning. Numerical analysis showed that patchy bimodal stomatal behavior occurred only during midday depression, suggesting that the distribution pattern of stomatal apertures (either uniform or non-uniform stomatal behavior) varies flexibly within single days. Direct observation of stomatal aperture using Suzuki's Universal Micro-Printing (SUMP) method demonstrated midday patchy stomatal closure that fits a bimodal pattern in Shorea leprosula Miq. , Shorea macrantha Brandis. and Dipterocarpus tempehes V.Sl. Inhibition of net assimilation rate and stomatal conductance appears to be a response to changes in vapor pressure deficit (VPD). Variable stomatal closure with increasing VPD is a mechanism used by a range of species to prevent excess water loss from leaves through evapotranspiration (viz., inhibition of midday leaf gas exchange). Bimodal stomatal closure may occur among adjacent stomata within a single patch, rather than among patches on a single leaf. Our results suggest the occurrence of patches at several scales within single leaves. Further analysis should consider variable spatial scales in heterogeneous stomatal behavior between and within patches and within single leaves.
Protein Phosphatase PPM1G Regulates Protein Translation and Cell Growth by Dephosphorylating 4E Binding Protein 1 (4E-BP1)*

Background: Phosphorylation of 4E-BP1 plays a critical role in controlling its ability to inhibit protein translation. Results: PPM1G is identified as a protein phosphatase that dephosphorylates 4E-BP1 in vitro and in cells. Conclusion: PPM1G negatively regulates protein translation by controlling the phosphorylation of 4E-BP1. Significance: PPM1G-mediated dephosphorylation of 4E-BP1 provides a novel mechanism in the regulation of protein translation. Protein translation initiation is a tightly controlled process responding to nutrient availability and mitogen stimulation. Serving as one of the most important negative regulators of protein translation, 4E binding protein 1 (4E-BP1) binds to translation initiation factor 4E and inhibits cap-dependent translation in a phosphorylation-dependent manner. Although it has been demonstrated previously that the phosphorylation of 4E-BP1 is controlled by mammalian target of rapamycin in the mammalian target of rapamycin complex 1, the mechanism underlying the dephosphorylation of 4E-BP1 remains elusive. Here, we report the identification of PPM1G as the phosphatase of 4E-BP1. A coimmunoprecipitation experiment reveals that PPM1G binds to 4E-BP1 in cells and that purified PPM1G dephosphorylates 4E-BP1 in vitro. Knockdown of PPM1G in 293E and colon cancer HCT116 cells results in an increase in the phosphorylation of 4E-BP1 at both the Thr-37/46 and Ser-65 sites. Furthermore, the time course of 4E-BP1 dephosphorylation induced by amino acid starvation or mammalian target of rapamycin inhibition is slowed down significantly in PPM1G knockdown cells. Functionally, the amount of 4E-BP1 bound to the cap-dependent translation initiation complex is decreased when the expression of PPM1G is depleted. As a result, the rate of cap-dependent translation, cell size, and protein content are increased in PPM1G knockdown cells. Taken together, our study has identified protein phosphatase PPM1G as a novel regulator of cap-dependent protein translation by negatively controlling the phosphorylation of 4E-BP1.
Variabilidad genética de Pinus nigra subsp. salzmannii en la Región de Murcia mediante microsatélites

En el presente trabajo se han utilizado cinco microsatelites cloroplasticos (cpSSR) para describir la diversidad genetica intrapoblacional y la diferenciacion genetica de Pinus nigra subsp. salzmannii de Murcia. El modelo de alelos infinitos (IAM) ha sido el utilizado para el analisis de la estructura genetica y la distribucion geografica de la variacion de las poblaciones, tanto naturales como reforestadas. En terminos generales, las poblaciones muestreadas presentan una gran variacion genetica intra e interpoblacional. Estos resultados pueden ser debidos a un descenso dramatico de las areas de distribucion, y a la fragmentacion de las poblaciones del Sureste iberico desde el Holoceno. Ademas, los datos obtenidos indican un claro patron geografico de la distribucion de la variacion genetica. Se sugiere que la poblacion del Rincon de los Huertos podria haberse originado a partir de poblaciones de distribucion Betica, mientras que las poblaciones de Sierra Espuna (repobladas) y El Carche podrian haberse originado a partir de poblaciones de rango iberico.
Direct Regulation of Microtubule Dynamics by KIF17 Motor and Tail Domains*

Background: KIF17 is targeted to microtubule plus-ends by EB1 and promotes microtubule stabilization in epithelial cells. Results: KIF17 motor and tail domains have direct and distinct effects on microtubule polymerization. Conclusion: The KIF17 motor domain is sufficient to regulate microtubules, but catalytic activity is modulated by EB1 and the KIF17 tail. Significance: KIF17 can function as a direct regulator of microtubule dynamics and stability. KIF17 is a kinesin-2 family motor that interacts with EB1 at microtubule (MT) plus-ends and contributes to MT stabilization in epithelial cells. The mechanism by which KIF17 affects MTs and how its activity is regulated are not yet known. Here, we show that EB1 and the KIF17 autoinhibitory tail domain (KIF17-Tail) interacted competitively with the KIF17 catalytic motor domain (K370). Both EB1 and KIF17-Tail decreased the K0.5MT of K370, with opposing effects on MT-stimulated ATPase activity. Importantly, K370 had independent effects on MT dynamic instability, resulting in formation of long MTs without affecting polymerization rate or total polymer mass. K370 also inhibited MT depolymerization induced by dilution in vitro and by nocodazole in cells, suggesting that it acts by protecting MT plus-ends. Interestingly, KIF17-Tail bound MTs and tubulin dimers, delaying initial MT polymerization in vitro and MT regrowth in cells. However, neither EB1 nor KIF17-Tail affected K370-mediated MT polymerization or stabilization significantly in vitro, and EB1 was dispensable for MT stabilization by K370 in cells. Thus, although EB1 and KIF17-Tail may coordinate KIF17 catalytic activity, our data reveal a novel and direct role for KIF17 in regulating MT dynamics.
Using complexity to promote group learning in health care.

RATIONALE Multidisciplinary groups are common in the health care arena, from operating teams to mental health treatment groups to guideline development groups. Differences among group members in information, background, training and skills can potentially help groups reach good decisions and complete complex tasks in variable circumstances. Too often, however, differences in values, status and preferences prevent these groups from achieving the potential benefits of diversity, marooning them instead in an unproductive fixed state. AIM Drawing on the literature on diversity and complex adaptive systems, we discuss how to improve the functioning of multidisciplinary groups by increasing the spontaneous flow of information and energy to shift groups into the complex state. CONCLUSION Differentiation needs to be balanced by integration. Differences that pose obstacles need to be transformed into gradients to achieve complex self-organization and effective group coordination.
Phospholipid Transfer Protein Is Expressed in Cerebrovascular Endothelial Cells and Involved in High Density Lipoprotein Biogenesis and Remodeling at the Blood-Brain Barrier*

Background: Liver X receptor activation promotes formation of HDL-like particles at the blood-brain barrier (BBB). Results: Cerebrovascular endothelial cells express phospholipid transfer protein (PLTP) that transfers phospholipids, remodels HDL, and supports cellular cholesterol efflux. Conclusion: PLTP is involved in HDL genesis and remodeling at the BBB. Significance: We demonstrate a direct role of PLTP in HDL metabolism at the blood-brain interface. Phospholipid transfer protein (PLTP) is a key protein involved in biogenesis and remodeling of plasma HDL. Several neuroprotective properties have been ascribed to HDL. We reported earlier that liver X receptor (LXR) activation promotes cellular cholesterol efflux and formation of HDL-like particles in an established in vitro model of the blood-brain barrier (BBB) consisting of primary porcine brain capillary endothelial cells (pBCEC). Here, we report PLTP synthesis, regulation, and its key role in HDL metabolism at the BBB. We demonstrate that PLTP is highly expressed and secreted by pBCEC. In a polarized in vitro model mimicking the BBB, pBCEC secreted phospholipid-transfer active PLTP preferentially to the basolateral (“brain parenchymal”) compartment. PLTP expression levels and phospholipid transfer activity were enhanced (up to 2.5-fold) by LXR activation using 24(S)-hydroxycholesterol (a cerebral cholesterol metabolite) or TO901317 (a synthetic LXR agonist). TO901317 administration elevated PLTP activity in BCEC from C57/BL6 mice. Preincubation of HDL3 with human plasma-derived active PLTP resulted in the formation of smaller and larger HDL particles and enhanced the capacity of the generated HDL particles to remove cholesterol from pBCEC by up to 3-fold. Pre-β-HDL, detected by two-dimensional crossed immunoelectrophoresis, was generated from HDL3 in pBCEC-derived supernatants, and their generation was markedly enhanced (1.9-fold) upon LXR activation. Furthermore, RNA interference-mediated PLTP silencing (up to 75%) reduced both apoA-I-dependent (67%) and HDL3-dependent (30%) cholesterol efflux from pBCEC. Based on these findings, we propose that PLTP is actively involved in lipid transfer, cholesterol efflux, HDL genesis, and remodeling at the BBB.
Carbon storage in trees: pathogens have their say.

The study of the role and dynamics of nonstructural carbohydrates (NSCs) in woody plants, and particularly in trees, has received renewed attention in the recent past (Sala et al. 2012, Dietze et al. 2014). There are several reasons for this increased interest but it seems clear that an important event was the publication of the McDowell et al. (2008) paper on the mecha-nism of drought-induced mortality in trees, in which the authors put forward the carbon-starvation hypothesis. According to this hypothesis, stomatal closure to prevent hydraulic failure under drought causes photosynthetic carbon uptake to dimin-ish and, eventually, the plant may deplete its carbon reserves and starve as a result of continued metabolic demand for carbohydrates. This idea was not new (e.g., Waring 1987, Martínez-Vilalta et al. 2002, Bréda et al. 2006), but McDowell et al. (2008) presented it in a coherent and wider hydraulic framework, which made it compelling and influential. The car-bon-starvation hypothesis implies that the amount and dynamics of carbohydrate storage in trees provide useful information on their drought responses. And off we went, many of us, to measure NSC concentrations in our field- and greenhouse-based studies of drought-induced tree mortality. The carbon-starvation hypothesis was controversial from the beginning (McDowell and Sevanto 2010, Sala et al. 2010) and,
Wood structural differences between northern and southern beech provenances growing at a moderate site.

Planting provenances originating from southern to northern locations has been discussed as a strategy to speed up species migration and mitigate negative effects of climate change on forest stability and productivity. Especially for drought-susceptible species such as European beech (Fagus sylvatica L.), the introduction of drought-tolerant provenances from the south could be an option. Yet, beech has been found to respond plastically to environmental conditions, suggesting that the climate on the plantation site might be more important for tree growth than the genetic predisposition of potentially drought-adapted provenances. In this study, we compared the radial growth, wood-anatomical traits and leaf phenology of four beech provenances originating from southern (Bulgaria, France) and northern locations (Sweden, the Netherlands) and planted in a provenance trial in the Netherlands. The distribution of precipitation largely differs between the sites of origin. The northern provenances experience a maximum and the southern provenances experience a minimum of rainfall in summer. We compared tree productivity and the anatomy of the water-conducting system for the period from 2000 to 2010, including the drought year 2003. In addition, tree mortality and the timing of leaf unfolding in spring were analysed for the years 2001, 2007 and 2012. Comparison of these traits in the four beech provenances indicates the influence of genetic predisposition and local environmental factors on the performance of these provenances under moderate site conditions. Variation in radial growth was controlled by environment, although the growth level slightly differed due to genetic background. The Bulgarian provenance had an efficient water-conducting system which was moreover unaffected by the drought in 2003, pointing to a high ability of this provenance to cope well with dry conditions. In addition, the Bulgarian provenance showed up as most productive in terms of height and radial growth. Altogether, we conclude that the similarity in ring-width variation among provenances points to environmental control of this trait, whereas the differences encountered in wood-anatomical traits between the well-performing Bulgarian provenance and the other three provenances, as well as the consistent differences in flushing pattern over 3 years under various environmental conditions, support the hypothesis of genetic control of these features.
Seroprevalence and incidence of Brucella sp among workers of the brucelosis control program in department of Antioquia, Colombia

* Autor para correspondencia: Luis Guillermo Palacio. Escuela de Medicina Veterinaria. Facultad de Ciencias Agrarias. Universidad de Antioquia. Cra 75 No 65-87, Teléfono (057) (4)2199120-2199121. Medellín, Colombia. Correo electrónico: lgpalaciob@gmail.com. Seroprevalencia e incidencia de Brucella sp en vacunadores del Programa para el control de brucelosis bovina, en el Departamento de Antioquia-Colombia¤
The Ets Transcription Factor EHF as a Regulator of Cornea Epithelial Cell Identity*

Background: Cornea development requires precise, coordinated gene expression; few regulators have been characterized. Results: Ets factor EHF collaborates with Kruppel-like factors to activate cornea epithelial genes while repressing non-epithelial genes. Conclusion: EHF, in collaboration with other transcription factors, promotes cornea epithelial identity. Significance: We generated a comprehensive data set on cornea gene expression over the lifetime of the mouse, identifying novel regulators of cornea epithelial identity. The cornea is the clear, outermost portion of the eye composed of three layers: an epithelium that provides a protective barrier while allowing transmission of light into the eye, a collagen-rich stroma, and an endothelium monolayer. How cornea development and aging is controlled is poorly understood. Here we characterize the mouse cornea transcriptome from early embryogenesis through aging and compare it with transcriptomes of other epithelial tissues, identifying cornea-enriched genes, pathways, and transcriptional regulators. Additionally, we profiled cornea epithelium and stroma, defining genes enriched in these layers. Over 10,000 genes are differentially regulated in the mouse cornea across the time course, showing dynamic expression during development and modest expression changes in fewer genes during aging. A striking transition time point for gene expression between postnatal days 14 and 28 corresponds with completion of cornea development at the transcriptional level. Clustering classifies co-expressed, and potentially co-regulated, genes into biologically informative categories, including groups that exhibit epithelial or stromal enriched expression. Based on these findings, and through loss of function studies and ChIP-seq, we show that the Ets transcription factor EHF promotes cornea epithelial fate through complementary gene activating and repressing activities. Furthermore, we identify potential interactions between EHF, KLF4, and KLF5 in promoting cornea epithelial differentiation. These data provide insights into the mechanisms underlying epithelial development and aging, identifying EHF as a regulator of cornea epithelial identity and pointing to interactions between Ets and KLF factors in promoting epithelial fate. Furthermore, this comprehensive gene expression data set for the cornea is a powerful tool for discovery of novel cornea regulators and pathways.
Heterogeneous Seeding of a Prion Structure by a Generic Amyloid Form of the Fungal Prion-forming Domain HET-s(218–289)*

Background: Prions are aberrantly folded infectious proteins whose biological activity is determined by their distinct folds. Results: The infectious fold of the fungal prion-forming domain HET-s(218–289) can be nucleated by a noninfectious polymorph. Conclusion: Generic amyloid architectures can seed the formation of infectious prions. Significance: Heterogeneous seeding may be a mechanism of prion strain adaptation and interspecies transmission. The fungal prion-forming domain HET-s(218–289) forms infectious amyloid fibrils at physiological pH that were shown by solid-state NMR to be assemblies of a two-rung β-solenoid structure. Under acidic conditions, HET-s(218–289) has been shown to form amyloid fibrils that have very low infectivity in vivo, but structural information about these fibrils has been very limited. We show by x-ray fiber diffraction that the HET-s(218–289) fibrils formed under acidic conditions have a stacked β-sheet architecture commonly found in short amyloidogenic peptides and denatured protein aggregates. At physiological pH, stacked β-sheet fibrils nucleate the formation of the infectious β-solenoid prions in a process of heterogeneous seeding, but do so with kinetic profiles distinct from those of spontaneous or homogeneous (seeded with infectious β-solenoid fibrils) fibrillization. Several serial passages of stacked β-sheet-seeded solutions lead to fibrillization kinetics similar to homogeneously seeded solutions. Our results directly show that structural mutation can occur between substantially different amyloid architectures, lending credence to the suggestion that the processes of strain adaptation and crossing species barriers are facilitated by structural mutation.
Glucose Regulates Hypothalamic Long-chain Fatty Acid Metabolism via AMP-activated Kinase (AMPK) in Neurons and Astrocytes*

Background: Hypothalamic long-chain fatty acids (LCFA) and glucose are critical for energy balance, but it is not known if their metabolism is coupled. Results: Glucose regulates hypothalamic metabolism of palmitate via AMP-activated kinase. Conclusion: Glucose and LCFA metabolism is coupled in a cell-type and LCFA-dependent manner. Significance: This is the first evidence for glucose regulation of LCFA metabolic fate in the hypothalamus. Hypothalamic controls of energy balance rely on the detection of circulating nutrients such as glucose and long-chain fatty acids (LCFA) by the mediobasal hypothalamus (MBH). LCFA metabolism in the MBH plays a key role in the control of food intake and glucose homeostasis, yet it is not known if glucose regulates LCFA oxidation and esterification in the MBH and, if so, which hypothalamic cell type(s) and intracellular signaling mechanisms are involved. The aim of this study was to determine the impact of glucose on LCFA metabolism, assess the role of AMP-activated Kinase (AMPK), and to establish if changes in LCFA metabolism and its regulation by glucose vary as a function of the kind of LCFA, cell type, and brain region. We show that glucose inhibits palmitate oxidation via AMPK in hypothalamic neuronal cell lines, primary hypothalamic astrocyte cultures, and MBH slices ex vivo but not in cortical astrocytes and slice preparations. In contrast, oleate oxidation was not affected by glucose or AMPK inhibition in MBH slices. In addition, our results show that glucose increases palmitate, but not oleate, esterification into neutral lipids in neurons and MBH slices but not in hypothalamic astrocytes. These findings reveal for the first time the metabolic fate of different LCFA in the MBH, demonstrate AMPK-dependent glucose regulation of LCFA oxidation in both astrocytes and neurons, and establish metabolic coupling of glucose and LCFA as a distinguishing feature of hypothalamic nuclei critical for the control of energy balance.