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1.
Mol Biol (Mosk) ; 55(4): 598-605, 2021.
Artigo em Russo | MEDLINE | ID: mdl-34432777

RESUMO

Recently, a wealth of data have been accumulating on the role of long non-coding RNAs (lncRNAs) in the fine-tuning of mRNA expression. Four new lncRNAs, namely, TMEM92-AS1, FAM222A-AS, TXLNB, and lnc-CCL28, were identified as differentially expressed in ovarian tumors using deep machine learning. The levels of lnc-CCL28 transcripts in both tumors and normal tissue samples were sufficient for further analysis by RT-PCR. In addition, the promising ovarian cancer biomarkers, lncRNAs LINC00152, NEAT 1 and SNHG17 were added to RT-PCR analysis. For the first time, an increase in the level of lnc-CCL28 and SNHG 17 lncRNAs was found in ovarian tumors, and the overexpression of LINC00152 and NEAT1 was confirmed. It seems that lnc-CCL28 is involved in carcinogenesis and, in particular, in ovarian cancer progression. Overexpression of LINC00152 and lnc-CCL28 was significantly associated with the later stages and metastasis.


Assuntos
Neoplasias Ovarianas , RNA Longo não Codificante , Carcinogênese/genética , Feminino , Humanos , Neoplasias Ovarianas/genética , RNA Longo não Codificante/genética
2.
J Biomol Struct Dyn ; 36(1): 221-232, 2018 01.
Artigo em Inglês | MEDLINE | ID: mdl-28024445

RESUMO

Structures of many metal-binding proteins are often obtained without structural cations in their apoprotein forms. Missing cation coordinates are usually updated from structural templates constructed from many holoprotein structures. Such templates usually do not include structural water, the important contributor to the ion binding energy. Structural templates are also inconvenient for taking into account structural modifications around the binding site at apo-/holo- transitions. An approach based upon statistical potentials readily takes into account structural modifications associated with binding as well as contribution of structural water molecules. Here, we construct a set of statistical potentials for Mg2+, Ca2+, and Zn2+ contacting with protein atoms of a different type or structural water oxygens. Each type of the cations tends to form tight contacts with protein atoms of specific types. Structural water contributes relatively more into the binding pseudo-energy of Mg2+ and Ca2+ than of Zn2+. We have developed PIONCA (Protein-Ion Calculator), a fast CUDA GPGPU-based algorithm that predicts ion-binding sites in apoproteins. Comparative tests demonstrate that PIONCA outperforms most of the tools based on structural templates or docking. Our software can be also used for locating bound cations in holoprotein structures with missing cation heteroatoms. PIONCA is equipped with an interactive web interface based upon JSmol.


Assuntos
Apoproteínas/química , Cátions/química , Metais/química , Água/química , Algoritmos , Apoproteínas/metabolismo , Sítios de Ligação , Cátions/metabolismo , Biologia Computacional/métodos , Metais/metabolismo , Ligação Proteica , Software , Termodinâmica
3.
Biofizika ; 60(1): 5-14, 2015.
Artigo em Russo | MEDLINE | ID: mdl-25868335

RESUMO

The work presents the results of an exhaustive conformational analysis of ß-turns involving amino acid residues with disallowed backbone conformation of the polypeptide chain. It is known that the first residue of the ß-turn (Asn47) of the distal ß-hairpin in the α-spectrin SH3-domain is characterized by sterically disallowed main chain conformation (values of the dihedral angles (φ and ψ are in the right bottom quadrant of the Ramachandran plot). All α-spectrin structures with the anomalous elements deposited in the PDB were analysed. We hypothesized that the formation of disallowed conformation may occur through the fixation (due to the SH3 domain structure) of the adjacent to the ß-turn amino acid residues with the ß-structure. These residues are disposed in such a manner that ß-turn conformation of the residues contributes just to the disallowed local conformation of this residue whereas any other ß-turn conformations (with allowed local conformation) are impossible. To test this hypothesis an exhaustive conformational analysis of the ß-bend has been performed by altering internal coordinates (two pairs of φ and ψ angles and two Ω angles). The conformations were selected as a result of grid search procedure with. 1 degrees step that corresponded to stereochemically allowed local deformations of the polypeptide chain segment forming the ß-turn. In all conformations obtained the local conformation of Asn47 rests in the disallowed region. The conformations found include conformations coinciding with experimentally determined structures from the PDB as well as an additional variant that differs from X-ray structure in values of a pair of φ and ψ angles of the second residue belonging to the ß-bend. Values of these angles fall in the region of the Ramachandran plot near the line φ = 0 (and negative values of ψ) i.e. in strongly disallowed region without experimental points. Therefore the additional variants of the ß-turn local deformation are impossible to observe in experiment. Thus, the idea that disallowed conformation is intruded to the ß-bend by fixation of adjacent residues receives confirmation in this work. The topological limitations in a context of the structure in such kind of ß-hairpins exclude the allowed local conformations.


Assuntos
Espectrina/química , Humanos , Estrutura Secundária de Proteína , Domínios de Homologia de src
4.
Genet Mol Res ; 13(2): 3972-80, 2014 May 23.
Artigo em Inglês | MEDLINE | ID: mdl-24938608

RESUMO

The starfish Asterias rubens is one of the most abundant echinoderm species in the White, Barents, North, and Baltic Seas. This species is an important component of marine ecosystems and a model object for certain biological studies, in particular those requiring quantitative estimation of gene expression. As a rule, expression at the transcriptional level is estimated by real-time qPCR using the ΔΔCt method, which allows the comparison of the copy number of target gene transcripts in samples with unknown mRNA/cDNA concentration. Application of this method requires normalization of the results relative to genes with stable expression levels (reference genes). The identification of reference genes is still a challenging task since data of this kind are missing for certain taxa, whereas the use of "standard" endogenous control genes without additional tests might lead to erroneous conclusions. We performed a preliminary analysis of the expression of many housekeeping genes in the pyloric ceca of A. rubens by high-throughput sequencing under normal and heat shock conditions. For one of them, the ubiquitin gene UBA52, low variation of expression (not greater than 2-fold) was shown using real-time qPCR. Tissues of pyloric ceca of normal adults and underyearlings and of adults after heat shock were used. The data obtained suggest that the UBA52 gene may be used as reference for normalization of gene expression at the mRNA level in the starfish A. rubens and probably in closely related species.


Assuntos
Regulação da Expressão Gênica/genética , Resposta ao Choque Térmico/genética , Proteínas/genética , RNA Mensageiro/genética , Ubiquitina/genética , Animais , Asterias , DNA Complementar/genética , Mucosa Gástrica/metabolismo , Sequenciamento de Nucleotídeos em Larga Escala , Reação em Cadeia da Polimerase em Tempo Real , Ubiquitina/biossíntese
5.
Biochemistry (Mosc) ; 79(12): 1405-11, 2014 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-25716736

RESUMO

More than 40% of human genes contain upstream open reading frames (uORF) in their 5'-untranslated regions (5'-UTRs) and at the same time express at least one truncated mRNA isoform containing no uORF. We studied translational regulation by four uORFs found in the 5'-UTR of full-length mRNA for SLAMF1, the gene encoding CD150 membrane protein. CD150 is a member of the CD2 superfamily, a costimulatory lymphocyte receptor, a receptor for measles virus, and a microbial sensor on macrophages. The SLAMF1 gene produces at least two mRNA isoforms that differ in their 5'-UTRs. In the long isoform of the SLAMF1 mRNA that harbors four uORFs in the 5'-UTR, the stop codon of uORF4 overlaps with the AUG codon of the main ORF forming a potential termination-reinitiation site UGAUG, while uORF2 and uORF3 start codons flank a sequence identical to Motif 1 from the TURBS regulatory element. TURBS was shown to be required for a coupled termination-reinitiation event during translation of polycistronic RNAs of some viruses. In a model cell system, reporter mRNA based on the 5'-UTR of SLAMF1 short isoform, which lacks any uORF, is translated 5-6 times more efficiently than the mRNA with 5'-UTR from the long isoform. Nucleotide substitutions disrupting start codons in either uORF2-4 result in significant increase in translation efficiency, while substitution of two nucleotides in TURBS Motif 1 leads to a 2-fold decrease in activity. These data suggest that TURBS-like elements can serve for translation control of certain cellular mRNAs containing uORFs.


Assuntos
Antígenos CD/biossíntese , Antígenos CD/genética , Fases de Leitura Aberta/genética , Biossíntese de Proteínas/genética , Isoformas de RNA/genética , Receptores de Superfície Celular/biossíntese , Receptores de Superfície Celular/genética , Regiões 5' não Traduzidas/genética , Fator de Iniciação 2 em Eucariotos/deficiência , Fator de Iniciação 4E em Eucariotos/deficiência , Genes Reporter/genética , Células HEK293 , Humanos , Mutagênese Sítio-Dirigida , Membro 1 da Família de Moléculas de Sinalização da Ativação Linfocitária
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