Search results for "Exon"
showing 10 items of 437 documents
Identifying four Trypanosoma cruzi I isolate haplotypes from different geographic regions in Colombia
2007
Abstract Trypanosoma cruzi has been classified into the groups T. cruzi I and T. cruzi II. The latter is subdivided into five smaller lineages based on multilocus enzyme electrophoresis and random amplified polymorphic DNA, designated as IIa-IIe, which shows correspondence with rRNA/mini-exon lineages. Twelve previously characterised T. cruzi isolates from different hosts, including humans, Didelphis marsupialis, and triatomines were analysed to establish genetic variability in T. cruzi group T. cruzi I isolates from different geographical regions of Colombia. DNA samples were sequenced based on the mini-exon gene intergenic region. Sequences were analysed using Clustal W, Staden 1.5 and ME…
Characterization of the length polymorphism in the A + T-rich region of the Drosophila obscura group species
1993
In the twelve Drosophila obscura group species studied, belonging to the affinis, obscura, and pseudoobscura subgroups, the mitochondrial DNA length ranges from 15.8 to 17.2 kb. This length polymorphism is mainly due to insertions/deletions in the variable region of the A + T-rich region. In addition, one species (D. tristis) possess a tandem duplication of a 470-bp fragment that contains the replication origin. The same duplication has occurred at least twice in the Drosophila evolutionary history due to the fact that the repetition is analogous to repetitions found in the four species of the D. melanogaster complex. By comparing the nucleotide sequence of the conserved region in D. ambigu…
All-atom simulations disentangle the functional dynamics underlying gene maturation in the intron lariat spliceosome
2018
The spliceosome (SPL) is a majestic macromolecular machinery composed of five small nuclear RNAs and hundreds of proteins. SPL removes noncoding introns from precursor messenger RNAs (pre-mRNAs) and ligates coding exons, giving rise to functional mRNAs. Building on the first SPL structure solved at near–atomic-level resolution, here we elucidate the functional dynamics of the intron lariat spliceosome (ILS) complex through multi-microsecond-long molecular-dynamics simulations of ∼1,000,000 atoms models. The ILS essential dynamics unveils (i) the leading role of the Spp42 protein, which heads the gene maturation by tuning the motions of distinct SPL components, and (ii) the critical particip…
Metallothionein Gene Family in the Sea Urchin Paracentrotus lividus: Gene Structure, Differential Expression and Phylogenetic Analysis
2017
Metallothioneins (MT) are small and cysteine-rich proteins that bind metal ions such as zinc, copper, cadmium, and nickel. In order to shed some light on MT gene structure and evolution, we cloned seven Paracentrotus lividus MT genes, comparing them to Echinodermata and Chordata genes. Moreover, we performed a phylogenetic analysis of 32 MTs from different classes of echinoderms and 13 MTs from the most ancient chordates, highlighting the relationships between them. Since MTs have multiple roles in the cells, we performed RT-qPCR and in situ hybridization experiments to understand better MT functions in sea urchin embryos. Results showed that the expression of MTs is regulated throughout de…
The nuclear autoantigen La/SS-associated antigen B: One gene, three functional mRNAs
1997
Transcription of the gene encoding for the nuclear autoantigen La resulted in three mRNA forms. A promoter switching combined with an alternative splicing pathway replaced exon 1 with either exon 1´ or exon 1´´. The exon 1´´ donor splice site was located 4 nts downstream of the exon 1´ donor splice site. All three La mRNA forms were expressed in all the tissues analysed including peripheral blood lymphocytes, liver, fetal spleen, cultured primary endothelial cells, and mouse LTA cell lines permanently transfected with the human La gene. Both the exons 1´ and 1´´ had unusual structures. They contained GC-rich regions and an oligo(U)-tail of 23 uridine residues. Moreover, they encoded for thr…
Cytoglobin: A Novel Globin Type Ubiquitously Expressed inVertebrate Tissues
2002
Vertebrates possess multiple respiratory globins that differ in terms of structure, function, and tissue distribution. Three types of globins have been described so far: hemoglobin facilitates the transport of oxygen in the blood, myoglobin serves oxygen transport and storage in the muscle, and neuroglobin has a yet unidentified function in nerve cells. Here we report the identification of a fourth and novel type of globin in mouse, man, and zebrafish. It is expressed in apparently all types of human tissue and therefore has been called cytoglobin (CYGB). Mouse and human CYGBs comprise 190 amino acids; the zebrafish CYGB, 174 amino acids. The human CYGB gene is located on chromosome 17q25. …
Splice donor site mutation in the lysosomal neuraminidase gene causing exon skipping and complete loss of enzyme activity in a sialidosis patient.
2001
Sialidosis is a lysosomal storage disease caused by the deficiency of K K-N-acetylneuraminidase (NEU1; sialidase), the key enzyme for the intralysosomal catabolism of sialylated glycoconjugates. We have identified a homozygous transversion in the last intron (IVSE +1 Gs C) in neu1 of a sialidosis patient. Sequencing of the truncated cDNA revealed an alternatively spliced neu1 transcript which lacks the complete sequence of exon 5. Skipping of exon 5 leads to a frameshift and results in a premature termination codon. This is the first description of an intronic point mutation causing a complete deficiency of the lysosomal neuraminidase activity. fl 2001 Federation of Euro- pean Biochemical S…
Conserved Structure and Promoter Sequence Similarity in the Mouse and Human Genes Encoding the Zinc Finger Factor BERF-1/BFCOL1/ZBP-89
2001
Abstract We have characterized the genomic structure of the mouse Zfp148 gene encoding Beta-Enolase Repressor Factor-1 (BERF-1), a Kruppel-like zinc finger protein involved in the transcriptional regulation of several genes, which is also termed ZBP-89, BFCOL1. The cloned Zfp148 gene spans 110 kb of genomic DNA encompassing the 5′-end region, 9 exons, 8 introns, and the 3′-untranslated region. The promoter region displays the typical features of a housekeeping gene: a high G+C content and the absence of canonical TATA and CAAT boxes consistent with the multiple transcription initiation sites determined by primary extension analysis. Computer-assisted search in the human genome database allo…
Sponges (Porifera) Molecular Model Systems to Study Cellular Differentiation in Metazoa
1998
Evolution is a gradual process whereby primarily new genes are formed either by gene duplication (Ohno 1970) or exon shuffling (Gilbert 1978). New proteins can also be produced by overlapping genes, alternative splicing or gene sharing (Li and Graur 1991). These facts imply that (1) proteins found in a given phylum contain elements or modules which are present already in ancestral protein(s) of members of phylogenetically older phyla and (2) that new combinations of such modules create proteins that possess new functions.
Definitive Link of Mutation c.351delC and Development of Hereditary Angioedema in a Large Brazilian Family
2011
S U N D A Y 381 Definitive Link of Mutation c.351delC and Development of Hereditary Angioedema in a Large Brazilian Family M. F. Ferraro, A. S. Moreno, E. Castelli, A. P. Lange, E. A. Donadi, K. Bork, W. Sarti, L. K. Arruda; School of Medicine of Ribeirao Preto, Ribeirao Preto, BRAZIL, Johannes-Gutenberg University, Mainz, GERMANY. RATIONALE:We have previously described the identification of a novel SERPING1 mutation (c.351delC) in members of a large Brazilian family with Hereditary Angioedema (HAE). In the present study, we have aimed to verify the association of this mutation with the development of HAE in this family. METHODS: Family pedigree was constructed with 275 individuals distribu…