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1.
We have characterized the biosynthesis of two metalloproteinases, procollagenase and prostromelysin, by rabbit brain capillary endothelial cells (RBCE) by means of immunochemical, biosynthetic, and functional assays. Unstimulated RBCE secreted no detectable metalloproteinases. Secretion of both procollagenase and prostromelysin was induced within 6 h by treating the cells with 50 ng/ml 12-O-tetradecanoylphorbol-13-acetate. In treated cells, the two proenzymes accounted for up to 20% of the [35S]methionine-labeled secreted proteins; about 15 micrograms of each protein was secreted in 48 h by 10(6) RBCE. Although RBCE secreted approximately as much procollagenase and prostromelysin as did rabbit fibroblasts, virtually no enzyme activity could be measured in RBCE-conditioned medium, even after activation of the proenzymes by trypsin or an organomercurial agent. 相似文献
2.
We have broadly defined the DNA regions regulating esterase6 activity in
several life stages and tissue types of D. melanogaster using P-
element-mediated transformation of constructs that contain the esterase6
coding region and deletions or substitutions in 5' or 3' flanking DNA.
Hemolymph is a conserved ancestral site of EST6 activity in Drosophila and
the primary sequences regulating its activity lie between -171 and -25 bp
relative to the translation initiation site: deletion of these sequences
decrease activity approximately 20-fold. Hemolymph activity is also
modulated by four other DNA regions, three of which lie 5' and one of which
lies 3' of the coding region. Of these, two have positive and two have
negative effects, each of approximately twofold. Esterase6 activity is
present also in two male reproductive tract tissues; the ejaculatory bulb,
which is another ancestral activity site, and the ejaculatory duct, which
is a recently acquired site within the melanogaster species subgroup.
Activities in these tissues are at least in part independently regulated:
activity in the ejaculatory bulb is conferred by sequences between -273 and
-172 bp (threefold decrease when deleted), while activity in the
ejaculatory duct is conferred by more distal sequences between -844 and
-614 bp (fourfold decrease when deleted). The reproductive tract activity
is further modulated by two additional DNA regions, one in 5' DNA (-613 to
-284 bp; threefold decrease when deleted) and the other in 3' DNA (+1860 to
+2731 bp; threefold decrease when deleted) that probably overlaps the
adjacent esteraseP gene. Collating these data with previous studies
suggests that expression of EST6 in the ancestral sites is mainly regulated
by conserved proximal sequences while more variable distal sequences
regulate expression in the acquired ejaculatory duct site.
相似文献
3.
Litman GW; Rast JP; Shamblott MJ; Haire RN; Hulst M; Roess W; Litman RT; Hinds- Frey KR; Zilch A; Amemiya CT 《Molecular biology and evolution》1993,10(1):60-72
Immunoglobulins are encoded by a large multigene system that undergoes
somatic rearrangement and additional genetic change during the development
of immunoglobulin-producing cells. Inducible antibody and antibody-like
responses are found in all vertebrates. However, immunoglobulin possessing
disulfide-bonded heavy and light chains and domain-type organization has
been described only in representatives of the jawed vertebrates. High
degrees of nucleotide and predicted amino acid sequence identity are
evident when the segmental elements that constitute the immunoglobulin gene
loci in phylogenetically divergent vertebrates are compared. However, the
organization of gene loci and the manner in which the independent elements
recombine (and diversify) vary markedly among different taxa. One striking
pattern of gene organization is the "cluster type" that appears to be
restricted to the chondrichthyes (cartilaginous fishes) and limits
segmental rearrangement to closely linked elements. This type of gene
organization is associated with both heavy- and light-chain gene loci. In
some cases, the clusters are "joined" or "partially joined" in the germ
line, in effect predetermining or partially predetermining, respectively,
the encoded specificities (the assumption being that these are expressed)
of the individual loci. By relating the sequences of transcribed gene
products to their respective germ-line genes, it is evident that, in some
cases, joined-type genes are expressed. This raises a question about the
existence and/or nature of allelic exclusion in these species. The
extensive variation in gene organization found throughout the vertebrate
species may relate directly to the role of intersegmental
(V<==>D<==>J) distances in the commitment of the individual
antibody-producing cell to a particular genetic specificity. Thus, the
evolution of this locus, perhaps more so than that of others, may reflect
the interrelationships between genetic organization and function.
相似文献
4.
Mouse macrophage elastase. Purification and characterization as a metalloproteinase. 总被引:28,自引:2,他引:26
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Macrophage elastase was purified from tissue-culture medium conditioned by inflammatory mouse peritoneal macrophages. Characterized as a secreted neutral metalloproteinase, this enzyme was shown to be catalytically and immunochemically distinct from the mouse pancreatic and mouse granulocyte elastases, both of which are serine proteinases. Inhibition profiles, production of nascent N-terminal leucine residues and sodium dodecyl sulphate/polyacrylamide-gel electrophoresis of degraded elastin indicated that macrophage elastase is an endopeptidase, with properties of a metalloproteinase, rather than a serine proteinase. Macrophage elastase was inhibited by alpha 2-macroglobulin, but not by alpha 1-proteinase inhibitor. Macrophage elastase was resolved into three chromatographically distinct forms. The predominant form had mol.wt. 22 000 and was purified 4100-fold. Purification of biosynthetically radiolabelled elastase indicated that this form represented less than 0.5% of the secreted protein of macrophages. Approx. 800% of the starting activity was recovered after purification. Evidence was obtained for an excess of an endogenous inhibitor masking more than 80% of the secreted activity. 相似文献
5.
K. Chavva S. Pillalamarri V. Banda S. Gautham J. Gaddamedi P. Yedla C.G. Kumar N. Banda 《Bioorganic & medicinal chemistry letters》2013,23(21):5893-5895
A series of novel alkyl amide functionalized trifluoromethyl substituted pyrazolo[3,4-b]pyridine derivatives 5, 6 and 7 were prepared starting from 6-phenyl-4-(trifluoromethyl)-1H-pyrazolo[3,4-b]pyridin-3-amine 3 via selective N-alkylation, followed by reaction with different primary aliphatic amines, cyclic secondary amines or l-amino acids under different set of conditions. All the synthesized compounds 5, 6 and 7 were screened for anticancer activity against four cancer cell lines such as A549—Lung cancer (CCL-185), MCF7—Breast cancer (HTB-22), DU145—Prostate cancer (HTB-81) and HeLa—Cervical cancer (CCL-2). The compounds 5i and 6e are found to have promising bioactivity at micro molar concentration. 相似文献
6.
Schistosomiasis vector snails are subjected to extreme seasonal changes, particularly in ephemeral rivers and lentic waterbodies. In the tropics, aestivation is one of the adaptive strategies for survival and is used by snails in times of extremely high temperatures and desiccation. Aestivation therefore plays an important role in maintaining the transmission of schistosomiasis. This review assesses the possible impacts of climate change on the temporal and spatial distribution of schistosomiasis-transmitting snails with special emphasis on aestivation, and discusses the effect of schistosome infection on aestivation ability. The impacts of parasite development on snails, as well as physiological changes, are discussed with reference to schistosomiasis transmission. This review shows that schistosome-infected snails have lower survival rates during aestivation, and that those that survive manage to get rid of the infection. In general, snail aestivation ability is poor and survival chances diminish with time. Longer dry periods result in fewer, as well as uninfected, snails. However, the ability of the surviving snails to repopulate the habitats is high. 相似文献
7.
Olga Joos Agbessi Amouzou Romesh Silva Benjamin Banda Lois Park Jennifer Bryce Mercy Kanyuka RMM Malawi working group 《PloS one》2016,11(1)
Background
Malawi ratified a compulsory birth and death registration system in 2009. Until it captures complete coverage of vital events, Malawi relies on other data sources to calculate mortality estimates. We tested a community-based method to estimate annual under-five mortality rates (U5MR) through the Real-Time Monitoring of Under-Five Mortality (RMM) project in Malawi. We implemented RMM in two phases, and conducted an independent evaluation of phase one after 21 months of implementation. We present results of the phase two validation that covers the full project time span, and compare the results to those of the phase one validation.Methods and Findings
We assessed the completeness of the counts of births and deaths and the accuracy of disaggregated U5MR from the community-based method against a retrospective full pregnancy history for rolling twelve-month periods after the independent evaluation. We used full pregnancy histories collected through household interviews carried out between November 2013 and January 2014 as the validation data source. Health Surveillance Agents (HSAs) across the 160 catchment areas submitted routine reports on pregnancies, births, and deaths consistently. However, for the 15-month implementation period post-evaluation, average completeness of birth event reporting was 76%, whereas average completeness of death event reporting was 67% relative to that expected from a comparable pregnancy history. HSAs underestimated the U5MR by an average of 21% relative to that estimated from a comparable pregnancy history.Conclusions
On a medium scale, the community-based RMM method in Malawi produced substantial underestimates of annualized U5MR relative to those obtained from a full pregnancy history, despite the additional incentives and quality-control activities. We were not able to achieve an optimum level of incentive and support to make the system work while ensuring sustainability. Lessons learned from the implementation of RMM can inform programs supporting community-based interventions through HSAs in Malawi. 相似文献8.
Attenuation of pattern recognition receptor signaling is mediated by a MAP kinase kinase kinase
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Sharon C Mithoe Christina Ludwig Michiel JC Pel Mara Cucinotta Alberto Casartelli Malick Mbengue Jan Sklenar Paul Derbyshire Silke Robatzek Corné MJ Pieterse Ruedi Aebersold Frank LH Menke 《EMBO reports》2016,17(3):441-454
Pattern recognition receptors (PRRs) play a key role in plant and animal innate immunity. PRR binding of their cognate ligand triggers a signaling network and activates an immune response. Activation of PRR signaling must be controlled prior to ligand binding to prevent spurious signaling and immune activation. Flagellin perception in Arabidopsis through FLAGELLIN‐SENSITIVE 2 (FLS2) induces the activation of mitogen‐activated protein kinases (MAPKs) and immunity. However, the precise molecular mechanism that connects activated FLS2 to downstream MAPK cascades remains unknown. Here, we report the identification of a differentially phosphorylated MAP kinase kinase kinase that also interacts with FLS2. Using targeted proteomics and functional analysis, we show that MKKK7 negatively regulates flagellin‐triggered signaling and basal immunity and this requires phosphorylation of MKKK7 on specific serine residues. MKKK7 attenuates MPK6 activity and defense gene expression. Moreover, MKKK7 suppresses the reactive oxygen species burst downstream of FLS2, suggesting that MKKK7‐mediated attenuation of FLS2 signaling occurs through direct modulation of the FLS2 complex. 相似文献
9.
Subías L Zaballos JP Banda E Fontal-Cazalla F Nieves-Aldrey JL 《Revista de biología tropical》2004,52(1):85-95
Taking part of the Program for The Inventory of Flora and Fauna of Coiba Island National Park (Panama), a first list of oribatid mites (Acari: Oribatei) is presented. Materials studied come from several soil samplings, including humus and fallen leaves, done in Coiba Island in July 1998. 134 species were identified from a total amount of 1053 individuals collected. Almost all the identified species are new records for Panama as well as eigth species that represent first records for the Neotropical Region. A new name is given: Aeroppia mariehammerae n. nom. for Aeroppia sp. and a new combination is proposed: Protoribates antillensis (Mahunka, 1985) n. comb. (Xylobates). 相似文献
10.