Search results for "Conserved sequence"
showing 10 items of 103 documents
Conserved TCR β chain usage in reactive arthritis; evidence for selection by a putative HLA-B27-associated autoantigen
2002
Previous work suggested that expanded CD8+ T-cell clones in the synovial fluid (SF) of HLA-B27+ patients with reactive arthritis (ReA) preferentially use the T-cell receptor variable region (TCRBV) 1, similar CDR3 sequences, and joining region (BJ) 2S3. To determine the range of conservation and disease-specificity of CDR3-sequences, we analyzed the TCRBV1-J2S3 repertoire from 33 healthy HLA-B27+ individuals, patients with various types of spondyloarthropathies (SpA), and with rheumatoid arthritis (RA) by CDR3-spectratyping. After collection and database submission of all available TCRB-CDR3 from HLA-B27-restricted or SpA-derived T cells, we systematically screened the entire human sequence…
A Globin Gene of Ancient Evolutionary Origin in Lower Vertebrates: Evidence for Two Distinct Globin Families in Animals
2004
Hemoglobin, myoglobin, neuroglobin, and cytoglobin are four types of vertebrate globins with distinct tissue distributions and functions. Here, we report the identification of a fifth and novel globin gene from fish and amphibians, which has apparently been lost in the evolution of higher vertebrates (Amniota). Because its function is presently unknown, we tentatively call it globin X (GbX). Globin X sequences were obtained from three fish species, the zebrafish Danio rerio, the goldfish Carassius auratus, and the pufferfish Tetraodon nigroviridis, and the clawed frog Silurana tropicalis. Globin X sequences are distinct from vertebrate hemoglobins, myoglobins, neuroglobins, and cytoglobins.…
BvCOLD1: A novel aquaporin from sugar beet (Beta vulgarisL.) involved in boron homeostasis and abiotic stress
2018
Beta vulgaris (sugar beet) is one of the most important industrial crops. Screening of a cDNA library for sugar beet genes able to confer cold tolerance upon overexpression in yeast identified a novel aquaporin, which we named BvCOLD1. The amino acid sequence of BvCOLD1 indicated that an acidic protein (pI 5.18) is similar to tonoplast intrinsic protein aquaporins. RNA expression analysis indicated that BvCOLD1 is expressed in all sugar beet organs. Confocal microscopy of a green fluorescent protein-tagged version localized BvCOLD1 in the endoplasmic reticulum in yeast and in plant cells. Experiments in yeast showed that BvCOLD1 has an important role in transporting several molecules, among…
Arthropod 7SK RNA
2008
The 7SK small nuclear RNA (snRNA) is a key player in the regulation of polymerase (pol) II transcription. The 7SK RNA was long believed to be specific to vertebrates where it is highly conserved. Homologs in basal deuterostomes and a few lophotrochozoan species were only recently reported. On longer timescales, 7SK evolves rapidly with only few conserved sequence and structure motifs. Previous attempts to identify the Drosophila homolog thus have remained unsuccessful despite considerable efforts. Here we report on the discovery of arthropod 7SK RNAs using a novel search strategy based on pol III promoters, as well as the subsequent verification of its expression. Our results demonstrate th…
Immunoaffinity purification and characterization of mitochondrial membrane-bound D-3-hydroxybutyrate dehydrogenase from Jaculus orientalis.
2008
Abstract Background The interconversion of two important energy metabolites, 3-hydroxybutyrate and acetoacetate (the major ketone bodies), is catalyzed by D-3-hydroxybutyrate dehydrogenase (BDH1: EC 1.1.1.30), a NAD+-dependent enzyme. The eukaryotic enzyme is bound to the mitochondrial inner membrane and harbors a unique lecithin-dependent activity. Here, we report an advanced purification method of the mammalian BDH applied to the liver enzyme from jerboa (Jaculus orientalis), a hibernating rodent adapted to extreme diet and environmental conditions. Results Purifying BDH from jerboa liver overcomes its low specific activity in mitochondria for further biochemical characterization of the e…
Why are the genomes of endosymbiotic bacteria so stable?
2003
The comparative analysis of three strains of the endosymbiotic bacterium Buchnera aphidicola has revealed high genome stability associated with an almost complete absence of chromosomal rearrangements and horizontal gene transfer events during the past 150 million years. The loss of genes involved in DNA uptake and recombination in the initial stages of endosymbiosis probably underlies this stability. Gene loss, which was extensive during the initial steps of Buchnera evolution, has continued in the different Buchnera lineages since their divergence.
Evolutionary conservation and function of the human embryonic stem cell specific miR-302/367 cluster
2015
miRNA clusters define a group of related miRNAs closely localized in the genome with an evolution that remains poorly understood. The miR-302/367 cluster represents a single polycistronic transcript that produces five precursor miRNAs. The cluster is highly expressed and essential for maintenance of human embryonic stem cells. We found the cluster to be highly conserved and present in most mammals. In primates, seed sequence and miRNA structure are conserved, but inter-precursor sequences are evolving. Insertions of new miRNAs, deletions of individual miRNAs, and a cluster duplication observed in different species suggest an actively evolving cluster. Core transcriptional machinery consisti…
Ectodomain shedding of CD99 within highly conserved regions is mediated by the metalloprotease meprin β and promotes transendothelial cell migration.
2016
The adhesion molecule CD99 is essential for the transendothelial migration of leukocytes. In this study, we used biochemical and cellular assays to show that CD99 undergoes ectodomain shedding by the metalloprotease meprin β and subsequent intramembrane proteolysis by γ-secretase. The cleavage site in CD99 was identified by mass spectrometry within an acidic region highly conserved through different vertebrate species. This finding fits perfectly to the unique cleavage specificity of meprin β with a strong preference for aspartate residues and suggests coevolution of protease and substrate. We hypothesized that limited CD99 cleavage by meprin β would alter cellular transendothelial migratio…
The new gene DmX from Drosophila melanogaster encodes a novel WD-repeat protein
1998
DmX is a novel gene from Drosophila melanogaster located on the X chromosome in region 5D5/6-E1. The molecular analysis of the genomic and cDNA sequences of DmX shows that the gene spans appr. 16kb and displays a mosaic structure with 15 exons. The 12kb long DmX transcript is present in Drosophila embryos, larvae and adults of both sexes. The open reading frame of DmX encodes a novel WD-repeat protein, containing at least 30 WD-repeat units. WD-repeat proteins contain a conserved motif of approximately 40 amino acids (aa), usually ending with the dipeptide Trp-Asp (WD). Homologues of the DmX gene exist in other dipteran species, in Caenorhabditis elegans and human, revealing that DmX is an …
The death-domain fold of the ASC PYRIN domain, presenting a basis for PYRIN/PYRIN recognition.
2003
The PYRIN domain is a conserved sequence motif identified in more than 20 human proteins with putative functions in apoptotic and inflammatory signalling pathways. The three-dimensional structure of the PYRIN domain from human ASC was determined by NMR spectroscopy. The structure determination reveals close structural similarity to death domains, death effector domains, and caspase activation and recruitment domains, although the structural alignment with these other members of the death-domain superfamily differs from previously predicted amino acid sequence alignments. Two highly positively and negatively charged surfaces in the PYRIN domain of ASC result in a strong electrostatic dipole …