Search results for "TERT"
showing 10 items of 1210 documents
RNA-binding ability of PIPP in requires the entire protein
2003
Post-transcriptional fate of eukaryotic mRNAs depends on association with different classes of RNA-binding proteins (RBPs). Among these proteins, the cold-shock domain (CSD)-containing proteins, also called Y-box proteins, play a key role in controlling the recruitment of mRNA to the translational machinery, in response to environmental cues, both in development and in differentiated cells. We recently cloned a rat cDNA encoding a new CSD-protein that we called PIPPin. This protein also contains two putative double-stranded RNA-binding motifs (PIP(1) and PIP(2)) flanking the central CSD, and is able to bind mRNAs encoding H1 degrees and H3.3 histone variants. In order to clarify the role of…
Polar/Ionizable Residues in Transmembrane Segments: Effects on Helix-Helix Packing
2012
The vast majority of membrane proteins are anchored to biological membranes through hydrophobic alpha-helices. Sequence analysis of high-resolution membrane protein structures show that ionizable amino acid residues are present in transmembrane (TM) helices, often with a functional and/or structural role. Here, using as scaffold the hydrophobic TM domain of the model membrane protein glycophorin A (GpA), we address the consequences of replacing specific residues by ionizable amino acids on TM helix insertion and packing, both in detergent micelles and in biological membranes. Our findings demonstrate that ionizable residues are stably inserted in hydrophobic environments, and tolerated in t…
Identification of new claudin family members by a novel PSI-BLAST based approach with enhanced specificity.
2006
In an attempt to develop a novel strategy for the identification of new members of protein families by in silico approaches, we have developed a semi-automated procedure of consecutive PSI-BLAST (Position-Specific-Iterated Basic Local Alignment Search Tool) searches incorporating identificiation as well as subsequent validation of putative candidates. For a proof of concept study we chose the search for novel members of the claudin family. The initial step was an iterated PSI-BLAST search starting with the PMP22_Claudin domain of each known member of the claudin family against the human part of the RefSeq Database. Putative new claudin domains derived from the converged list were evaluated …
Bioinformatic flowchart and database to investigate the origins and diversity of Clan AA peptidases
2009
Abstract Background Clan AA of aspartic peptidases relates the family of pepsin monomers evolutionarily with all dimeric peptidases encoded by eukaryotic LTR retroelements. Recent findings describing various pools of single-domain nonviral host peptidases, in prokaryotes and eukaryotes, indicate that the diversity of clan AA is larger than previously thought. The ensuing approach to investigate this enzyme group is by studying its phylogeny. However, clan AA is a difficult case to study due to the low similarity and different rates of evolution. This work is an ongoing attempt to investigate the different clan AA families to understand the cause of their diversity. Results In this paper, we…
Three-dimensional structure of the anaphase-promoting complex.
2001
The anaphase-promoting complex (APC) is a cell cycle-regulated ubiquitin-protein ligase, composed of at least 11 subunits, that controls progression through mitosis and G1. Using cryo-electron microscopy and angular reconstitution, we have obtained a three-dimensional model of the human APC at a resolution of 24 A. The APC has a complex asymmetric structure 140 A x 140 A x 135 A in size, in which an outer protein wall surrounds a large inner cavity. We discuss the possibility that this cavity represents a reaction chamber in which ubiquitination reactions take place, analogous to the inner cavities formed by other protein machines such as the 26S proteasome and chaperone complexes. This cag…
Red blood with blue-blood ancestry: Intriguing structure of a snail hemoglobin
2006
The phylogenetic enigma of snail hemoglobin, its isolated occurrence in a single gastropod family, the Planorbidae, and the lack of sequence data, stimulated the present study. We present here the complete cDNA and predicted amino acid sequence of two hemoglobin polypeptides from the planorbid Biomphalaria glabrata (intermediate host snail for the human parasite Schistosoma mansoni ). Both isoforms contain 13 different, cysteine-free globin domains, plus a small N-terminal nonglobin “plug” domain with three cysteines for subunit dimerization (total M r ≈ 238 kDa). We also identified the native hemoglobin molecule and present here a preliminary 3D reconstruction from electron microscopical …
The Metalloprotease Meprin β Generates Amino Terminal-truncated Amyloid β Peptide Species
2012
The amyloid β (Aβ) peptide, which is abundantly found in the brains of patients suffering from Alzheimer disease, is central in the pathogenesis of this disease. Therefore, to understand the processing of the amyloid precursor protein (APP) is of critical importance. Recently, we demonstrated that the metalloprotease meprin β cleaves APP and liberates soluble N-terminal APP (N-APP) fragments. In this work, we present evidence that meprin β can also process APP in a manner reminiscent of β-secretase. We identified cleavage sites of meprin β in the amyloid β sequence of the wild type and Swedish mutant of APP at positions p1 and p2, thereby generating Aβ variants starting at the first or seco…
Support policy for the tourism business: a comparative case study in Spain
2009
It is now well known that service industries, and especially the tourism sector, significantly contribute to economic and social development in the European Union. Intrinsic to the growth of the tourism industry has been the public interventions that, directly or indirectly, have facilitated the development of this sector. In this context, this paper aims to contribute to the knowledge on the design and implementation process of support policies for tourism businesses in Spain, using institutional economics as the theoretical framework. Based on a comparative case study, the article shows that despite the relevance of the legal system, the most important factors for the promotion of the tou…
Developing and Testing Speaking Skills in Academic Discourse
2014
Teaching speaking is an essential aspect of developing students’ sociolinguistic competence in a foreign language at any level. English studies at the tertiary level offer a variety of courses for practicing speaking and helping students reach the C1 and C2 level in BA and MA studies, respectively. However, it is not only the level that differentiates between BA and MA studies, but also aspects of register and style. Beginning with the subjects generally called Conversation, Speaking, Oral reproduction, Argumentation skills, Debating or Public speaking (BA studies), students gradually advance to Conversation based on academic texts (MA studies). This transition requires students to raise th…
Päiväkirjagenren moniäänisyys
2016
Yksityisen tekstilajin salassa muotoutuvia piirteitä on vaikeampi seurata kuin vapaasti luettavien lehtitekstien tai julkisten asiakirjojen genremuutoksia. Intiimit tekstilajit jäävät helposti tutkimatta. Tässä tutkielmassa tarkastellaan päiväkirjaa yksityisenä tekstilajina. Päiväkirja on tunnistettava ja iäkäs, mutta samalla henkilökohtainen ja kirjoittajansa tarkoituksiin mukautuva genre, mikä tekee sen vakaudesta suhteellista. Suhteellinen vakaus on Bahtinin mukaan genren ominaispiirre. Jotkin genret ovat vakaampia ja toiset dynaamisia. Genret tasapainoilevat kahden niihin vaikuttavan voiman välillä. Keskihakuinen voima pyrkii säilyttämään genren yhtenäisenä ja keskipakoinen voima paljas…