Search results for "Base Sequence"
showing 10 items of 1146 documents
The membrane distal half of gp130 is responsible for the formation of a ternary complex with IL-6 and the IL-6 receptor
1995
AbstractGp130 is the signal transducing subunit of the interleukin-6 receptor. Signaling is initiated by the complex formation of gp130 with IL-6 bound to the IL-6 receptor (IL-6R). We have subdivided the extracellular domain of gp130 in two parts and expressed the mutant proteins as soluble IgG fusion proteins in COS-7 cells. By studying the formation of the ternary complex we show that the membrane distal half of gp130 which contains a cytokine receptor domain is responsible for the interaction with the IL-6/IL-6R complex. Interestingly this is the same region which is believed to be involved in specific recognition of the related cytokines LIF, OM, and probably also of CNTF and IL-11.
Functional variants of 5S rRNA in the ribosomes of common sea urchin Paracentrotus lividus
2012
Abstract We have previously reported a molecular and cytogenetic characterization of three different 5S rDNA clusters in the sea urchin Paracentrotus lividus ; this study, performed at DNA level only, lends itself as starting point to verify that these clusters could contain transcribed genes, then, to demonstrate the presence of heterogeneity at functional RNA level, also. In the present work we report in P. lividus ribosomes the existence of several transcribed variants of the 5S rRNA and we associate all transcribed variants to the cluster to which belong. Our finding is the first demonstration of the presence of high heterogeneity in functional 5S rRNA molecules in animal ribosomes, a f…
The coat protein of prunus necrotic ringspot virus specifically binds to and regulates the conformation of its genomic RNA
2003
AbstractBinding of coat protein (CP) to the 3′ nontranslated region (3′-NTR) of viral RNAs is a crucial requirement to establish the infection of Alfamo- and Ilarviruses. In vitro binding properties of the Prunus necrotic ringspot ilarvirus (PNRSV) CP to the 3′-NTR of its genomic RNA using purified E. coli- expressed CP and different synthetic peptides corresponding to a 26-residue sequence near the N-terminus were investigated by electrophoretic mobility shift assays. PNRSV CP bound to, at least, three different sites existing on the 3′-NTR. Moreover, the N-terminal region between amino acid residues 25 to 50 of the protein could function as an independent RNA-binding domain. Single exchan…
Side-stepping secondary symbionts: widespread horizontal transfer across and beyond the Aphidoidea.
2003
To elucidate the co-evolutionary relationships between phloem-feeding insects and their secondary, or facultative, bacterial symbionts, we explore the distributions of three such microbes--provisionally named the R-type (or PASS, or S-sym), T-type (or PABS), and U-type--across a number of aphid and psyllid hosts through the use of diagnostic molecular screening techniques and DNA sequencing. Although typically maternally transmitted, phylogenetic and pairwise divergence analyses reveal that these bacteria have been independently acquired by a variety of unrelated insect hosts, indicating that horizontal transfer has helped to shape their distributions. Based on the high genetic similarity b…
Multiple Ig-like featuring genes divergent within and among individuals of the marine sponge Geodia cydonium.
1998
Abstract The receptor tyrosine kinase of the marine sponge Geodia cydonium features two extracellular Ig-like domains in which we recently documented RT-PCR polymorphism among individuals. Genomic-PCR analysis presented here revealed 14 unique sequences from four sponges, differing predominantly in the sequence of an intron which splits the Ig-like domains. Nevertheless, analysis of putative coding regions in 19 distinct clones (156–159 aa) from seven sponges revealed 69 positions of nucleotide substitutions, 67.6% of them non-synonymous, translating into 43 positions of divergent residues. Excluding aa deletions, these 19 sequences share pairwise aa identities of 89–99%. In three sponges, …
Truncated internalin A and asymptomatic Listeria monocytogenes carriage: in vivo investigation by allelic exchange
2004
ABSTRACT Allelic exchange of the region coding for the C terminus of InlA between one epidemic (with an 80-kDa InlA) and one asymptomatic (with a 47-kDa InlA) carriage Listeria monocytogenes strain confirmed the need for this region for internalin entry in vitro. Interestingly, restoration of internalin A functionality did not result in full virulence in chicken embryo assays.
Expression of one sponge Iroquois homeobox gene in primmorphs from Suberites domuncula during canal formation
2003
SUMMARY Sponges (Porifera) represent the evolutionary oldest multicellular animals. They are provided with the basic molecules involved in cell–cell and cell–matrix interactions. We report here the isolation and characterization of a complementary DNA from the sponge Suberites domuncula coding for the sponge homeobox gene, SUBDOIRX-a. The deduced polypeptide with a predicted Mr of 44,375 possesses the highly conserved Iroquois-homeodomain. We applied in situ hybridization to localize Iroquois in the sponge. The expression of this gene is highest in cells adjacent to the canals of the sponge in the medulla region. To study the expression of Iroquois during development, the in vitro primmorph…
Cloning of a DNA fragment encoding part of a 70-kDa heat shock protein ofCandida albicans
1995
Immunoscreening of a mycelial expression library with polyclonal antibodies raised against mycelial cell wall resulted in the detection of a cDNA encoding a heat shock protein of Candida albicans. Sequence analysis of a 0.8-kb cDNA subclone, 2M-1, revealed an open reading frame encoding 244 amino acids. Southern blot analysis with this fragment as a probe demonstrated hybridization to C. albicans DNA. Northern analysis showed a substantial increase in 2M RNA expression levels after cells were subjected to heat shock. Western blot analysis with 2M monospecific antibodies recognized a 70-kDa protein which was present in membrane particles and cytosolic fractions.
Cloning and characterization of PRB1, a Candida albicans gene encoding a putative novel endoprotease B and factors affecting its expression
2002
Abstract Several cDNA fragments corresponding to transcripts differentially expressed under conditions that favor mycelial growth of Candida albicans were identified by the “differential display” technique. One of these was cloned and used as a probe to rescue the full gene from a genomic library of the fungus. The sequence identified a single, uninterrupted open reading frame of 1395 nucleotides encoding a putative protein of 465 residues and a theoretical molecular weight of 50.3 kDa, present in the genome as a single copy located at chromosome 2 in different strains. The gene product showed high homology with subtilisin-like proteases, mainly PRB1, the vacuolar B protease from Saccharomy…
Interspecies comparison of neuroglobin, cytoglobin and myoglobin: Sequence evolution and candidate regulatory elements
2003
Neuroglobin and cytoglobin are two novel members of the vertebrate globin family. Their physiological role is poorly understood, although both proteins bind oxygen reversibly and may be involved in cellular oxygen homeostasis. Here we investigate the selective constraints on coding and non-coding sequences of the neuroglobin and cytoglobin genes in human, mouse, rat and fish. Neuroglobin and cytoglobin are highly conserved, displaying very low levels of non-synonymous nucleotide substitutions. An oxygen supply function predicts distinct modes of gene regulation, involving hypoxia-responsive transcription factors. To detect conserved candidate regulatory elements, we compared the neuroglobin…