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1.
Killing of Escherichia coli cells modulated by components of the stability system ParD of plasmid R1
Alicia Bravo Sagrario Ortega Gertrudis de Torrontegui Ramón Díaz 《Molecular & general genetics : MGG》1988,215(1):146-151
Summary The proteins P10 and P12 have been shown to be gene products of a new stability system, ParD, of plasmid R1. It is now shown that an R1 miniplasmid, pAB112, carrying a trans-complementable amber mutation in the gene of the P10 protein, is lethal for the host in the absence of suppression. This lethal effect is suppressed in a supF background and also by deletions in pAB112 that affect the gene of the P12 protein. These data indicate that the P12 protein has a lethal effect on the host and that this effect is neutralized by the P10 protein. The possibility that the stabilization conferred by the ParD system could be due to a counterselection, mediated by P12, of cells that lose the plasmid at cell division, is discussed. 相似文献
2.
Russell B. Lingham Keith C. Silverman Gerald F. Bills Carmen Cascales Manual Sanchez Rosalind G. Jenkins Suzanne E. Gartner Isabel Martin Maria T. Diez Fernando Peláez Sagrario Mochales Yu-Lin Kong Richard W. Burg Maria S. Meinz Leeyuan Huang Mary Nallin-Omstead Scott D. Mosser Michael D. Schaber Charles A. Omer David L. Pompliano Jackson B. Gibbs Sheo B. Singh 《Applied microbiology and biotechnology》1993,40(2-3):370-374
Chaetomellic acids A and B, isolated from Chaetomella acutiseta, are specific inhibitors of farnesyl-protein transferase that do not inhibit geranylgeranyl transferase type 1 or squalene synthase. Chaetomellic acids A and B are reversible inhibitors, resemble farnesyl diphosphate and probably inhibit FPTase by substituting for farnesyl diphosphate. Chaetomellic acid production appears to be widespread within the genus Chaetomella.
Correspondence to: R. B. Lingham 相似文献
3.
Paloma Bermejo-Bescós Sagrario Martín-Aragón Andrea Ortega Eduardo Buxaderas Aurelio G. Csákÿ 《Biochemical and biophysical research communications》2010,400(1):169-174
The aim of this study is to find out whether several 1,4-naphthoquinones (1,4-NQ) can interact with the amyloidogenic pathway of the amyloid precursor protein processing, particularly targeting at β-secretase (BACE), as well as at β-amyloid peptide (Aβ) aggregation and disaggregating preformed Aβ fibrils. Compounds bearing hydroxyl groups at the quinoid (2) or benzenoid rings (5, 6) as well as some 2- and 3-aryl derivatives (11-15) showed BACE inhibitory activity, without effect on amyloid aggregation or disaggregation. The halogenated compounds 8 and 10 were selective for the inhibition of amyloid aggregation. On the other hand, 1,4-naphthoquinone (1), 6-hydroxy-1,4-naphthoquinone (4) and 2-(3,4-dichlorophenyl)-1,4-naphthoquinone (26) did not show any BACE inhibitory activity but were active on amyloid aggregation and disaggregation preformed Aβ fibrils. Juglone (5-hydroxy-1,4-naphthoquinone (3), and 3-(p-hydroxyphenyl)-5-methoxy-1,4-napththoquinone (19) were active on all the three targets. Therefore, we suggest that 1,4-NQ derivatives, specially 3 and 19, should be explored as possible drug candidates or lead compounds for the development of drugs to prevent amyloid aggregation and neurotoxicity in Alzheimer’s disease. 相似文献
4.
Junoy, J., Montalvo, S., Roldán, C. and García‐Corrales, P. 2000. Ultrastructural study of the bacillary, granular and mucoid proboscidial gland cells of Riseriellus occultus (Nemertini, Heteronemertini). — Acta Zoologica (Stockholm) 81 : 235–242. The ultrastructure of six types (G5‐G10) of proboscidial gland cells whose cell necks emerge independently on the epithelium surface is analysed and compared with data from other nemerteans. These types differ in cytological features, as well as in the morphology of their respective secretory granules. Secretory granules of the types G5 and G6 have a bacillary shape, and differ from each other based on their contents and dimensions. Secretory granules of the types G7 and G8 are spherical to ovoid; type G8 gland cells are monociliated, and their secretory granules contain a paracrystalline material. Types G9 and G10 gland cells are typically goblet‐shaped; secretory granules in the type G9 have a spherical shape, contain a homogeneous electron dense material and maintain their individuality, whereas those of the G10 type are elongate and have fibrillar contents, showing a tendency to fuse before they are extruded. The mucus sheet of the proboscis is responsible for lubrication of its epithelial surface. Secretion products of type G10 gland cells form the background substance of this mucus, and those of the G5 type confer stickiness to it. Type G9 gland cells could provide the toxic component to the mucus, and type G7 and G8 gland cells could be concerned with the production of enzymatic secretions. 相似文献
5.
Fernández-Miranda G Trakala M Martín J Escobar B González A Ghyselinck NB Ortega S Cañamero M Pérez de Castro I Malumbres M 《Development (Cambridge, England)》2011,138(13):2661-2672
Mitosis is controlled by multiple kinases that drive cell cycle progression and prevent chromosome mis-segregation. Aurora kinase B interacts with survivin, borealin and incenp to form the chromosomal passenger complex (CPC), which is involved in the regulation of microtubule-kinetochore attachments and cytokinesis. Whereas genetic ablation of survivin, borealin or incenp results in early lethality at the morula stage, we show here that aurora B is dispensable for CPC function during early cell divisions and aurora B-null embryos are normally implanted. This is due to a crucial function of aurora C during these early embryonic cycles. Expression of aurora C decreases during late blastocyst stages resulting in post-implantation defects in aurora B-null embryos. These defects correlate with abundant prometaphase figures and apoptotic cell death of the aurora B-deficient inner cell mass. Conditional deletion of aurora B in somatic cells that do not express aurora C results in chromosomal misalignment and lack of chromosome segregation. Re-expression of wild-type, but not kinase-dead, aurora C rescues this defect, suggesting functional overlap between these two kinases. Finally, aurora B-null cells partially arrest in the presence of nocodazole, suggesting that this kinase is not essential for the spindle assembly checkpoint. 相似文献
6.
Strategy for Cloning Large Gene Assemblages as Illustrated Using the Phenylacetate and Polyhydroxyalkanoate Gene Clusters 下载免费PDF全文
Beln García Elías R. Olivera ngel Sandoval Elsa Arias-Barrau Sagrario Arias Germn Naharro Jos M. Luengo 《Applied microbiology》2004,70(8):5019-5025
We report an easy procedure for isolating chromosome-clustered genes. By following this methodology, the entire set of genes belonging to the phenylacetic acid (PhAc; 18-kb) pathway as well as those required for the synthesis and mobilization of different polyhydroxyalkanoates (PHAs; 6.4 kb) in Pseudomonas putida U were recovered directly from the bacterial chromosome and cloned into a plasmid for the first time. The transformation of different bacteria with these genetic constructions conferred on them the ability to either degrade PhAc or synthesize bioplastics (PHAs). 相似文献
7.
Adult Sox2+ stem cell exhaustion in mice results in cellular senescence and premature aging 下载免费PDF全文
Jéssica M. Vilas Carmen Carneiro Sabela Da Silva‐Álvarez Alba Ferreirós Patricia González María Gómez Sagrario Ortega Manuel Serrano Tomás García‐Caballero Miguel González‐Barcia Anxo Vidal Manuel Collado 《Aging cell》2018,17(5)
Aging is characterized by a gradual functional decline of tissues with age. Adult stem and progenitor cells are responsible for tissue maintenance, repair, and regeneration, but during aging, this population of cells is decreased or its activity is reduced, compromising tissue integrity and causing pathologies that increase vulnerability, and ultimately lead to death. The causes of stem cell exhaustion during aging are not clear, and whether a reduction in stem cell function is a cause or a consequence of aging remains unresolved. Here, we took advantage of a mouse model of induced adult Sox2+ stem cell depletion to address whether accelerated stem cell depletion can promote premature aging. After a short period of partial repetitive depletion of this adult stem cell population in mice, we observed increased kyphosis and hair graying, and reduced fat mass, all of them signs of premature aging. It is interesting that cellular senescence was identified in kidney after this partial repetitive Sox2+ cell depletion. To confirm these observations, we performed a prolonged protocol of partial repetitive depletion of Sox2+ cells, forcing regeneration from the remaining Sox2+ cells, thereby causing their exhaustion. Senescence specific staining and the analysis of the expression of genetic markers clearly corroborated that adult stem cell exhaustion can lead to cellular senescence induction and premature aging. 相似文献
8.
Sabela Búa Peggy Sotiropoulou Cecilia Sgarlata Luis R Borlado Manuel Eguren Orlando Domínguez Sagrario Ortega Marcos Malumbres Cedric Blanpain Juan Méndez 《Cell cycle (Georgetown, Tex.)》2015,14(24):3897-3907
Cdc6 encodes a key protein for DNA replication, responsible for the recruitment of the MCM helicase to replication origins during the G1 phase of the cell division cycle. The oncogenic potential of deregulated Cdc6 expression has been inferred from cellular studies, but no mouse models have been described to study its effects in mammalian tissues. Here we report the generation of K5-Cdc6, a transgenic mouse strain in which Cdc6 expression is deregulated in tissues with stratified epithelia. Higher levels of CDC6 protein enhanced the loading of MCM complexes to DNA in epidermal keratinocytes, without affecting their proliferation rate or inducing DNA damage. While Cdc6 overexpression did not promote skin tumors, it facilitated the formation of papillomas in cooperation with mutagenic agents such as DMBA. In addition, the elevated levels of CDC6 protein in the skin extended the resting stage of the hair growth cycle, leading to better fur preservation in older mice. 相似文献
9.
Sagrario Gámez-Virués Geoff Gurr Anantanarayanan Raman John La Salle Helen Nicol 《BioControl》2009,54(2):211-218
Significant worldwide interest in conservation biological control in agricultural systems currently exists but little information
is available on the usefulness of this approach in farm forestry. In a field experiment conducted in a native vegetated shelterbelt
in central-west New South Wales, we measured the diversity of wasps in plots comprising Eucalyptus blakelyi Maiden (Myrtaceae) trees with and without a groundcover of Lobularia maritima (L.) Desv. (Brassicaceae). Vacuum samples revealed a greater abundance and species richness of parasitic wasps in the plots
comprising trees surrounded by the L. maritima groundcover. Cotesia sp. (Hymenoptera: Braconidae), Pteromalus sp. (Hymenoptera: Pteromalidae), Anagyrus sp. (Hymenoptera: Encyrtidae), Entedoninae sp. and Eulophidae sp. 1 (Hymenoptera: Eulophidae) were the most common taxa.
These were more abundant also in the trees with the L. maritima groundcover. Ardozyga stratifera (Meyrick) (Lepidoptera: Gelechiidae) larvae, that were naturally infesting the E. blakelyi trees, were significantly more parasitized in the trees with the L. maritima groundcover. Results indicate that parasitic wasps associated with a native-tree shelterbelt in Australia were amenable to
manipulation via groundcover vegetation.
相似文献
John La SalleEmail: |
10.
Karim Jiménez-Aligaga Paloma Bermejo-Bescós Sagrario Martín-Aragón Aurelio G. Csákÿ 《Bioorganic & medicinal chemistry letters》2013,23(2):426-429
Alkenylboronic acids have shown important biological activities that contribute to neuroprotection. We have determined their influence on the β-amyloid (βA) aggregation process, β-secretase and acethylcholinesterase activities on cell-free systems, on the redox and lipid peroxidation status, and on the vulnerability to apoptotic death in an APPswe neuroblastoma cell line, before and after hydrogen peroxide treatment. We have discovered that 2-arylvinylboronic acids and some of their esters possess a set of properties which makes them highly useful as neuroprotective agents affecting multiple biological targets involved in AD. These properties are not paralleled by the related 2-arylboronic acids. 相似文献