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1.
Transplant Proc ; 54(4): 1127-1133, 2022 May.
Artigo em Inglês | MEDLINE | ID: mdl-35430094

RESUMO

In the pandemic year 2020, 634 allogeneic hematopoietic stem-cell (HSC) transplants were performed in Poland, including fully matched and haploidentical family donors (n = 248) as well as unrelated donors transplantation (n = 386). In 48 recipients (7.6%) for allogeneic transplantation, hematopoietic bone marrow cells were transplanted, and in 586 recipients (92.4%), peripheral blood hematopoietic cells. The effect of the pandemic was noticeable but not disastrous-the number of HSC transplants from unrelated donors was lower by 9% compared to 2019 and the use of haploidentical donors slightly increased compared to 2019. Out of all 386 unrelated HSC transplants, the material for 143 transplants (37%) came from international donors, whereas for 243 transplants (63%) material collected from domestic donors was used. Along with the increase in the number of potential bone marrow donors in the national resources, the share of transplants from Polish donors in the total number of transplants increased noticeably from 2006 to 2020. The total number of allogeneic transplants performed in 18 Polish transplant centers between 2006 and 2020 is 7426. Total transplant rates (cumulative number of all allogeneic HSC transplants performed from 2006 to 2020 per 1 million inhabitants) differs between regions and for regions with nonzero number of transplants varies from 520 in Mazowieckie Voivodship to 14 in Lodzkie Voivodship.


Assuntos
Transplante de Células-Tronco Hematopoéticas , Transplante de Células-Tronco Hematopoéticas/efeitos adversos , Humanos , Polônia , Sistema de Registros , Transplante Homólogo , Doadores não Relacionados
2.
PeerJ ; 9: e11051, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33854844

RESUMO

The presence of many completely uncharacterized proteins, even in well-studied organisms such as humans, seriously hampers full understanding of the functioning of the living cells. ADP-ribosylation is a common post-translational modification of proteins; also nucleic acids and small molecules can be modified by the covalent attachment of ADP-ribose. This modification, important in cellular signalling and infection processes, is usually executed by enzymes from the large superfamily of ADP-ribosyltransferases (ARTs). Here, using bioinformatics approaches, we identify a novel putative ADP-ribosyltransferase family, conserved in eukaryotic evolution, with a divergent active site. The hallmark of these proteins is the ART domain nestled between flanking leucine-rich repeat (LRR) domains. LRRs are typically involved in innate immune surveillance. The novel family appears as putative novel ADP-ribosylation-related actors, most likely pseudoenzymes. Sequence divergence and lack of clearly detectable "classical" ART active site suggests the novel domains are pseudoARTs, yet atypical ART activity, or alternative enzymatic activity cannot be excluded. We propose that this family, including its human member LRRC9, may be involved in an ancient defense mechanism, with analogies to the innate immune system, and coupling pathogen detection to ADP-ribosyltransfer or other signalling mechanisms.

3.
Transplant Proc ; 52(7): 2011-2014, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32499141

RESUMO

Poland's Central Unrelated Potential Bone Marrow Donor and Cord Blood Registry (CBMDR Poltransplant) was established in 2011. Affiliated with the World Marrow Donor Association (WMDA) as PL5, the CBMDR is an internationally recognized hematopoietic stem cell donor registry with a large, high-quality donor database. Overall, Polish resources in this domain are the second largest in Europe and the fourth largest in the world, accounting for 4.8% of the WMDA Register of over 33.5 million records. In the last 10 years, the number of potential hematopoietic stem cell donors registered in Poland has increased more than 10-fold, from about 146,000 to 1,579,809 at the end of 2018. Such a growing number of donors in the CBMDR is contributing to an increase in overall numbers of donor searches in Polish databases, as well as in donations from Polish donors.


Assuntos
Transplante de Células-Tronco Hematopoéticas , Células-Tronco Hematopoéticas , Sistema de Registros , Doadores de Tecidos/provisão & distribuição , Obtenção de Tecidos e Órgãos/organização & administração , Bancos de Sangue , Medula Óssea , Europa (Continente) , Sangue Fetal , Humanos , Polônia
4.
HLA ; 95(6): 516-531, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-31970929

RESUMO

A catalog of common, intermediate and well-documented (CIWD) HLA-A, -B, -C, -DRB1, -DRB3, -DRB4, -DRB5, -DQB1 and -DPB1 alleles has been compiled from over 8 million individuals using data from 20 unrelated hematopoietic stem cell volunteer donor registries. Individuals are divided into seven geographic/ancestral/ethnic groups and data are summarized for each group and for the total population. P (two-field) and G group assignments are divided into one of four frequency categories: common (≥1 in 10 000), intermediate (≥1 in 100 000), well-documented (≥5 occurrences) or not-CIWD. Overall 26% of alleles in IPD-IMGT/HLA version 3.31.0 at P group resolution fall into the three CIWD categories. The two-field catalog includes 18% (n = 545) common, 17% (n = 513) intermediate, and 65% (n = 1997) well-documented alleles. Full-field allele frequency data are provided but are limited in value by the variations in resolution used by the registries. A recommended CIWD list is based on the most frequent category in the total or any of the seven geographic/ancestral/ethnic groups. Data are also provided so users can compile a catalog specific to the population groups that they serve. Comparisons are made to three previous CWD reports representing more limited population groups. This catalog, CIWD version 3.0.0, is a step closer to the collection of global HLA frequencies and to a clearer view of HLA diversity in the human population as a whole.


Assuntos
Alelos , Genética Populacional , Antígenos de Histocompatibilidade Classe II/genética , Antígenos de Histocompatibilidade Classe I/genética , Frequência do Gene , Haplótipos , Humanos
5.
Hum Immunol ; 81(2-3): 49-51, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31902540

RESUMO

Next-generation sequencing (NGS)-based typings of HLA-A, B, C, DQB1 and DRB1 loci were performed from 2018 to 2019 in 23 595 newly recruited or re-typed adult potential bone marrow donors registered in Poltransplant Registry to characterize allele and haplotype frequencies of HLA system for loci important for hematopoietic stem cell transplantation. The donors were recruited for registry and not for any other purpose including controls in a disease association study. The population sample was collected in various regions of Poland including all voivodships. The data regarding the degree of relatedness among individuals in the sample were not collected. Typings were supported by public funds as a part of the Polish National Program for Transplant Medicine Development. HLA frequency data are available in the Allele Frequencies Net Database.


Assuntos
Frequência do Gene/genética , Genética Populacional , Antígenos HLA/genética , Transplante de Medula Óssea , Haplótipos , Sequenciamento de Nucleotídeos em Larga Escala , Teste de Histocompatibilidade , Humanos , Polônia , Sistema de Registros , Doadores de Tecidos
6.
Proc Natl Acad Sci U S A ; 116(31): 15495-15504, 2019 07 30.
Artigo em Inglês | MEDLINE | ID: mdl-31311869

RESUMO

Members of the New Kinase Family 3 (NKF3), PEAK1/SgK269 and Pragmin/SgK223 pseudokinases, have emerged as important regulators of cell motility and cancer progression. Here, we demonstrate that C19orf35 (PEAK3), a newly identified member of the NKF3 family, is a kinase-like protein evolutionarily conserved across mammals and birds and a regulator of cell motility. In contrast to its family members, which promote cell elongation when overexpressed in cells, PEAK3 overexpression does not have an elongating effect on cell shape but instead is associated with loss of actin filaments. Through an unbiased search for PEAK3 binding partners, we identified several regulators of cell motility, including the adaptor protein CrkII. We show that by binding to CrkII, PEAK3 prevents the formation of CrkII-dependent membrane ruffling. This function of PEAK3 is reliant upon its dimerization, which is mediated through a split helical dimerization domain conserved among all NKF3 family members. Disruption of the conserved DFG motif in the PEAK3 pseudokinase domain also interferes with its ability to dimerize and subsequently bind CrkII, suggesting that the conformation of the pseudokinase domain might play an important role in PEAK3 signaling. Hence, our data identify PEAK3 as an NKF3 family member with a unique role in cell motility driven by dimerization of its pseudokinase domain.


Assuntos
Proteínas do Citoesqueleto/metabolismo , Multimerização Proteica , Proteínas Tirosina Quinases/metabolismo , Proteínas Proto-Oncogênicas c-crk/metabolismo , Motivos de Aminoácidos , Sequência de Aminoácidos , Animais , Células COS , Membrana Celular/metabolismo , Forma Celular , Chlorocebus aethiops , Sequência Conservada , Proteínas do Citoesqueleto/química , Evolução Molecular , Células HEK293 , Humanos , Filogenia , Ligação Proteica , Domínios Proteicos , Mapeamento de Interação de Proteínas , Proteínas Tirosina Quinases/química
7.
PeerJ ; 7: e6863, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31106069

RESUMO

The presence of many completely uncharacterized proteins, even in well-studied organisms such as humans, seriously hampers a full understanding of the functioning of living cells. One such example is the human protein C12ORF4, which belongs to the DUF2362 family, present in many eukaryotic lineages and conserved in metazoans. The only functional information available on C12ORF4 (Chromosome 12 Open Reading Frame 4) is its involvement in mast cell degranulation and its being a genetic cause of autosomal intellectual disability. Bioinformatics analysis of the DUF2362 family provides strong evidence that it is a novel member of the Macro clan/superfamily. Sequence similarity analysis versus other representatives of the Macro superfamily of ADP-ribose-binding proteins and mapping sequence conservation on predicted three-dimensional structure provides hypotheses regarding the molecular function for members of the DUF2362 family. For example, the available functional data suggest a possible role for C12ORF4 in ADP-ribosylation signaling in asthma and related inflammatory diseases. This novel family appears to be a likely novel ADP-ribosylation "reader" and "eraser," a previously unnoticed putative new player in cell signaling by this emerging post-translational modification.

8.
PeerJ ; 6: e4599, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29666759

RESUMO

Many kinases are still 'orphans,' which means knowledge about their substrates, and often also about the processes they regulate, is lacking. Here, DIA1/C3orf58, a member of a novel predicted kinase-like family, is shown to be present in the endoplasmic reticulum and to influence trafficking via the secretory pathway. Subsequently, DIA1 is subjected to phosphoproteomics analysis to cast light on its signalling pathways. A liquid chromatography-tandem mass spectrometry proteomic approach with phosphopeptide enrichment is applied to membrane fractions of DIA1-overexpressing and control HEK293T cells, and phosphosites dependent on the presence of DIA1 are elucidated. Most of these phosphosites belonged to CK2- and proline-directed kinase types. In parallel, the proteomics of proteins immunoprecipitated with DIA1 reported its probable interactors. This pilot study provides the basis for deeper studies of DIA1 signalling.

9.
Proc Natl Acad Sci U S A ; 113(25): E3482-91, 2016 06 21.
Artigo em Inglês | MEDLINE | ID: mdl-27185916

RESUMO

The modification of proteins by phosphorylation occurs in all life forms and is catalyzed by a large superfamily of enzymes known as protein kinases. We recently discovered a family of secretory pathway kinases that phosphorylate extracellular proteins. One member, family with sequence similarity 20C (Fam20C), is the physiological Golgi casein kinase. While examining distantly related protein sequences, we observed low levels of identity between the spore coat protein H (CotH), and the Fam20C-related secretory pathway kinases. CotH is a component of the spore in many bacterial and eukaryotic species, and is required for efficient germination of spores in Bacillus subtilis; however, the mechanism by which CotH affects germination is unclear. Here, we show that CotH is a protein kinase. The crystal structure of CotH reveals an atypical protein kinase-like fold with a unique mode of ATP binding. Examination of the genes neighboring cotH in B. subtilis led us to identify two spore coat proteins, CotB and CotG, as CotH substrates. Furthermore, we show that CotH-dependent phosphorylation of CotB and CotG is required for the efficient germination of B. subtilis spores. Collectively, our results define a family of atypical protein kinases and reveal an unexpected role for protein phosphorylation in spore biology.


Assuntos
Proteínas Quinases , Esporos Bacterianos/genética , Bacillus subtilis/genética , Proteínas de Bactérias/química , Proteínas do Capsídeo , Fosforilação
10.
Ann Transplant ; 20: 588-95, 2015 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-26423563

RESUMO

This paper describes bone marrow donation and transplantation in Poland in terms of its history, current state, and information on the quality control system. Based on data gathered from the informatics systems of the Polish Central Unrelated Potential Bone Marrow Donor and Cord Blood Registry and the Polish transplant registries, as well as World Marrow Donor Association statistics, we performed an overview study to collect and compare numbers on hematopoietic stem cells donations and transplantations in Poland in the years 2010-2014. In the last 5 years, the number of registered potential hematopoietic stem cells donors in Poland increased by more than 4 times, from about 146,000 to over 750,000. During the same period, the number of patients qualified to hematopoietic stem cells transplantation from unrelated donor increased from 557 in 2010 to 817 in 2014. We observed a striking change in the percentage of transplantations performed in Polish centers using material collected from national donors--from 24% to 60%. This shift was also evident in the number of search procedures closed with acceptation of Polish donors--from 27% in 2010 to 58% in 2014. Another consequence of Polish registry growth is the increasing number of donations from Polish donors for international patients. Between 2010 and 2014, the percent of donation for non-national patient increased from 33% to 76%, placing Poland in 6th place in the ranking of the HSC "exporters" worldwide. Growth of transplantation rates involves standardization process, which is a natural way of development for national organizations in the field of HSCT because of its international character.


Assuntos
Transplante de Células-Tronco Hematopoéticas/estatística & dados numéricos , Sistema de Registros , Doadores de Tecidos/estatística & dados numéricos , Obtenção de Tecidos e Órgãos/organização & administração , Transplante de Medula Óssea/métodos , Transplante de Medula Óssea/estatística & dados numéricos , Feminino , Transplante de Células-Tronco Hematopoéticas/métodos , Humanos , Incidência , Masculino , Inovação Organizacional , Polônia
11.
PLoS One ; 9(1): e85428, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24454864

RESUMO

Annexins are Ca(2+)-binding, membrane-interacting proteins, widespread among eukaryotes, consisting usually of four structurally similar repeated domains. It is accepted that vertebrate annexins derive from a double genome duplication event. It has been postulated that a single domain annexin, if found, might represent a molecule related to the hypothetical ancestral annexin. The recent discovery of a single-domain annexin in a bacterium, Cytophaga hutchinsonii, apparently confirmed this hypothesis. Here, we present a more complex picture. Using remote sequence similarity detection tools, a survey of bacterial genomes was performed in search of annexin-like proteins. In total, we identified about thirty annexin homologues, including single-domain and multi-domain annexins, in seventeen bacterial species. The thorough search yielded, besides the known annexin homologue from C. hutchinsonii, homologues from the Bacteroidetes/Chlorobi phylum, from Gemmatimonadetes, from beta- and delta-Proteobacteria, and from Actinobacteria. The sequences of bacterial annexins exhibited remote but statistically significant similarity to sequence profiles built of the eukaryotic ones. Some bacterial annexins are equipped with additional, different domains, for example those characteristic for toxins. The variation in bacterial annexin sequences, much wider than that observed in eukaryotes, and different domain architectures suggest that annexins found in bacteria may actually descend from an ancestral bacterial annexin, from which eukaryotic annexins also originate. The hypothesis of an ancient origin of bacterial annexins has to be reconciled with the fact that remarkably few bacterial strains possess annexin genes compared to the thousands of known bacterial genomes and with the patchy, anomalous phylogenetic distribution of bacterial annexins. Thus, a massive annexin gene loss in several bacterial lineages or very divergent evolution would appear a likely explanation. Alternative evolutionary scenarios, involving horizontal gene transfer between bacteria and protozoan eukaryotes, in either direction, appear much less likely. Altogether, current evidence does not allow unequivocal judgement as to the origin of bacterial annexins.


Assuntos
Anexinas/genética , Proteínas de Bactérias/genética , Sequência de Aminoácidos , Animais , Anexinas/química , Bactérias/genética , Proteínas de Bactérias/química , Biologia Computacional , Sequência Conservada , Humanos , Anotação de Sequência Molecular , Dados de Sequência Molecular , Filogenia , Estrutura Terciária de Proteína
12.
PLoS One ; 8(6): e66427, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23840464

RESUMO

The catalogues of protein kinases, the essential effectors of cellular signaling, have been charted in Metazoan genomes for a decade now. Yet, surprisingly, using bioinformatics tools, we predicted protein kinase structure for proteins coded by five related human genes and their Metazoan homologues, the FAM69 family. Analysis of three-dimensional structure models and conservation of the classic catalytic motifs of protein kinases present in four out of five human FAM69 proteins suggests they might have retained catalytic phosphotransferase activity. An EF-hand Ca(2+)-binding domain in FAM69A and FAM69B proteins, inserted within the structure of the kinase domain, suggests they may function as Ca(2+)-dependent kinases. The FAM69 genes, FAM69A, FAM69B, FAM69C, C3ORF58 (DIA1) and CXORF36 (DIA1R), are by large uncharacterised molecularly, yet linked to several neurological disorders in genetics studies. The C3ORF58 gene is found deleted in autism, and resides in the Golgi. Unusually high cysteine content and presence of signal peptides in some of the family members suggest that FAM69 proteins may be involved in phosphorylation of proteins in the secretory pathway and/or of extracellular proteins.


Assuntos
Proteínas de Ligação ao Cálcio/química , Doenças do Sistema Nervoso/enzimologia , Proteínas Quinases/química , Proteínas Adaptadoras de Transporte Vesicular/química , Motivos de Aminoácidos , Sequência de Aminoácidos , Transtorno Autístico/enzimologia , Domínio Catalítico , Análise por Conglomerados , Biologia Computacional , Sequência Conservada , Humanos , Proteínas de Membrana/química , Modelos Moleculares , Dados de Sequência Molecular , Homologia de Sequência de Aminoácidos , Homologia Estrutural de Proteína
13.
PLoS One ; 8(5): e62272, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23671590

RESUMO

The zinc-dependent metalloproteases with His-Glu-x-x-His (HExxH) active site motif, zincins, are a broad group of proteins involved in many metabolic and regulatory functions, and found in all forms of life. Human genome contains more than 100 genes encoding proteins with known zincin-like domains. A survey of all proteins containing the HExxH motif shows that approximately 52% of HExxH occurrences fall within known protein structural domains (as defined in the Pfam database). Domain families with majority of members possessing a conserved HExxH motif include, not surprisingly, many known and putative metalloproteases. Furthermore, several HExxH-containing protein domains thus identified can be confidently predicted to be putative peptidases of zincin fold. Thus, we predict zincin-like fold for eight uncharacterised Pfam families. Besides the domains with the HExxH motif strictly conserved, and those with sporadic occurrences, intermediate families are identified that contain some members with a conserved HExxH motif, but also many homologues with substitutions at the conserved positions. Such substitutions can be evolutionarily conserved and non-random, yet functional roles of these inactive zincins are not known. The CLCAs are a novel zincin-like protease family with many cases of substituted active sites. We show that this allegedly metazoan family has a number of bacterial and archaeal members. An extremely patchy phylogenetic distribution of CLCAs in prokaryotes and their conserved protein domain composition strongly suggests an evolutionary scenario of horizontal gene transfer (HGT) from multicellular eukaryotes to bacteria, providing an example of eukaryote-derived xenologues in bacterial genomes. Additionally, in a protein family identified here as closely homologous to CLCA, the CLCA_X (CLCA-like) family, a number of proteins is found in phages and plasmids, supporting the HGT scenario.


Assuntos
Genoma Humano/genética , Metaloproteases/genética , Família Multigênica/genética , Filogenia , Motivos de Aminoácidos/genética , Sequência de Aminoácidos , Proteínas Arqueais/genética , Proteínas de Bactérias/genética , Bases de Dados de Proteínas , Humanos , Metaloproteases/classificação , Dados de Sequência Molecular , Homologia de Sequência de Aminoácidos
14.
Acta Biochim Pol ; 59(3): 401-6, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22924162

RESUMO

Metacaspases, cysteine proteases belonging to the peptidase C14 family, are suspected of being involved in the programmed cell death of plants, although their sequences and substrate specificity differ from those of animal caspases. At present, the knowledge on the metacaspase reaction mechanism is based only on biochemical data and homology models constructed on caspase templates. Here we propose a novel template for metacaspase modeling and demonstrate important advantages in comparison to the conventionally used caspase templates. We also point out the connection between plant and bacterial metacaspases, underlining the prokaryotic roots of Programmed Cell Death (PCD).


Assuntos
Caspases/química , Geobacter/enzimologia , Análise de Sequência de Proteína/métodos , Homologia de Sequência de Aminoácidos , Triticum/enzimologia , Algoritmos , Sequência de Aminoácidos , Proteínas de Bactérias/química , Caspase 7/química , Domínio Catalítico , Morte Celular , Bases de Dados de Proteínas , Humanos , Modelos Moleculares , Dados de Sequência Molecular , Proteínas de Plantas/química , Dobramento de Proteína , Estrutura Secundária de Proteína , Alinhamento de Sequência , Especificidade por Substrato
15.
PLoS One ; 7(2): e32138, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22359664

RESUMO

Selenoproteins serve important functions in many organisms, usually providing essential oxidoreductase enzymatic activity, often for defense against toxic xenobiotic substances. Most eukaryotic genomes possess a small number of these proteins, usually not more than 20. Selenoproteins belong to various structural classes, often related to oxidoreductase function, yet a few of them are completely uncharacterised.Here, the structural and functional prediction for the uncharacterised selenoprotein O (SELO) is presented. Using bioinformatics tools, we predict that SELO protein adopts a three-dimensional fold similar to protein kinases. Furthermore, we argue that despite the lack of conservation of the "classic" catalytic aspartate residue of the archetypical His-Arg-Asp motif, SELO kinases might have retained catalytic phosphotransferase activity, albeit with an atypical active site. Lastly, the role of the selenocysteine residue is considered and the possibility of an oxidoreductase-regulated kinase function for SELO is discussed.The novel kinase prediction is discussed in the context of functional data on SELO orthologues in model organisms, FMP40 a.k.a.YPL222W (yeast), and ydiU (bacteria). Expression data from bacteria and yeast suggest a role in oxidative stress response. Analysis of genomic neighbourhoods of SELO homologues in the three domains of life points toward a role in regulation of ABC transport, in oxidative stress response, or in basic metabolism regulation. Among bacteria possessing SELO homologues, there is a significant over-representation of aquatic organisms, also of aerobic ones. The selenocysteine residue in SELO proteins occurs only in few members of this protein family, including proteins from Metazoa, and few small eukaryotes (Ostreococcus, stramenopiles). It is also demonstrated that enterobacterial mchC proteins involved in maturation of bactericidal antibiotics, microcins, form a distant subfamily of the SELO proteins.The new protein structural domain, with a putative kinase function assigned, expands the known kinome and deserves experimental determination of its biological role within the cell-signaling network.


Assuntos
Selenoproteínas/química , Oxirredução , Proteínas Quinases , Estrutura Terciária de Proteína , Selenocisteína , Selenoproteínas/genética , Selenoproteínas/fisiologia
16.
Biol Blood Marrow Transplant ; 15(9): 1014-25, 2009 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-19660714

RESUMO

In hematopoietic stem cell transplantation (HSCT), the outcome is predicted using HLA-matching procedures, which are very time-consuming. There exists substantial evidence of the importance of early donor acceptance in HSCT outcome. In cases when the donor cannot be perfectly matched, it often is unclear which mismatch is less harmful and thus has a greater likelihood of acceptance. We modeled and analyzed interactions between the protein products of different HLA alleles of the transplant recipient and natural killer and T lymphocyte cell receptors of the donor's immune system. Reactions between these 2 systems often lead to graft-versus-host disease (GVHD). Sequence polymorphisms that define HLA I and II alleles predict not only GVHD, but also host-versus-graft and graft-versus-leukemia effects, all of which influence the overall transplantation outcome. Although complete high-resolution HLA matching of the donor-recipient pair seems to be associated with optimal post-HSCT survival, recent reports suggest that not every HLA disparity is functionally relevant. We performed interaction energy calculations for selected pairs of donor-recipient HLA alleles. Based on the results, we conclude that the energy of contact between the T lymphocyte cell receptor (TCR) and HLA residues can help predict the future development of an immune reaction and, consequently, the outcome of allogeneic HSCT.


Assuntos
Antígenos HLA-B/imunologia , Transplante de Células-Tronco Hematopoéticas , Alelos , Sequência de Aminoácidos , Doença Enxerto-Hospedeiro/genética , Doença Enxerto-Hospedeiro/imunologia , Antígenos HLA-B/química , Antígenos HLA-B/genética , Teste de Histocompatibilidade , Humanos , Estimativa de Kaplan-Meier , Modelos Moleculares , Dados de Sequência Molecular , Valor Preditivo dos Testes , Receptores de Antígenos de Linfócitos T/química , Receptores de Antígenos de Linfócitos T/imunologia , Alinhamento de Sequência , Termodinâmica , Resultado do Tratamento
17.
Biosystems ; 80(2): 193-9, 2005 May.
Artigo em Inglês | MEDLINE | ID: mdl-15823418

RESUMO

Directional mutation pressure associated with replication processes is the main cause of the asymmetry between the leading and lagging DNA strands in bacterial genomes. On the other hand, the asymmetry between sense and antisense strands of protein coding sequences is a result of both mutation and selection pressures. Thus, there are two different ways of superposition of the sense strand, on the leading or lagging strand. Besides many other implications of these two possible situations, one seems to be very important - because of the asymmetric replication-associated mutation pressure, the mutation rate of genes depends on their location. Using Monte Carlo methods, we have simulated, under experimentally determined directional mutation pressure, the divergence rate and the elimination rate of genes depending on their location in respect to the leading/lagging DNA strands in the asymmetric prokaryotic genome. We have found that the best survival strategy for the majority of genes is to sometimes switch between DNA strands. Paradoxically, this strategy results in higher substitution rates but remains in agreement with observations in bacterial genomes that such inversions are very frequent and divergence rate between homologs lying on different DNA strands is very high.


Assuntos
Evolução Biológica , Borrelia burgdorferi/genética , Análise Mutacional de DNA/métodos , Variação Genética/genética , Modelos Genéticos , Mutação/genética , Seleção Genética , Substituição de Aminoácidos/genética , Mapeamento Cromossômico/métodos , Simulação por Computador , Análise de Sobrevida
18.
Appl Bioinformatics ; 3(1): 31-9, 2004.
Artigo em Inglês | MEDLINE | ID: mdl-16323964

RESUMO

This paper analyses the relationship between the mutation data matrix 1PAM/PET91, representing the effect of both mutation and selection pressures exerted on 16130 homologous proteins of different organisms, and a mutation probability matrix (1PAM/MPM) representing the effect of pure mutation pressure on protein coding of the Borrelia burgdorferi genome. The 1PAM/PMP matrix was derived with the help of computer simulations, which used empirical nucleotide substitution rates found for the B. burgdorferi genome. Here, it is shown that the frequency of amino acid occurrence is strongly related to their effective survival time. We found that the shorter the turnover time of an amino acid under pure mutation pressure, the lower its fraction in the proteins coded by the genome and the more protected by selection pressure is its position in proteins. Results of analyses suggest that during evolution the mutational pressure has been optimised to some extent to the selection requirements.


Assuntos
Borrelia burgdorferi/genética , Mapeamento Cromossômico/métodos , Análise Mutacional de DNA/métodos , DNA Bacteriano/genética , Variação Genética/genética , Proteoma/genética , Seleção Genética , Algoritmos , Genoma Bacteriano , Mutação , Fases de Leitura Aberta/genética
19.
J Appl Genet ; 44(4): 561-84, 2003.
Artigo em Inglês | MEDLINE | ID: mdl-14617839

RESUMO

One of the common features of bacterial genomes is a strong compositional asymmetry between differently replicating DNA strands (leading and lagging). The main cause of the observed bias is the mutational pressure associated with replication. This suggests that genes translocated between differently replicating DNA strands are subjected to a higher mutational pressure, which may influence their composition and divergence rate. Analyses of groups of completely sequenced bacterial genomes have revealed that the highest divergence rate is observed for the DNA sequences that in closely related genomes are located on different DNA strands in respect to their role in replication. Paradoxically, for this group of sequences the absolute values of divergence rate are higher for closely related species than for more diverged ones. Since this effect concerns only the specific group of orthologs, there must be a specific mechanism introducing bias into the structure of chromosome by enriching the set of homologs in trans position in newly diverged species in relatively highly diverged sequences. These highly diverged sequences may be of varied nature: (1) paralogs or other fast-evolving genes under weak selection; or (2) pseudogenes that will probably be eliminated from the genome during further evolution; or (3) genes whose history after divergence is longer than the history of the genomes in which they are found. The use of these highly diverged sequences for phylogenetic analyses may influence the topology and branch length of phylogenetic trees. The changing mutational pressure may contribute to arising of genes with new functions as well.


Assuntos
Evolução Molecular , Genoma Bacteriano , Filogenia , Recombinação Genética
20.
Acta Microbiol Pol ; 52(3): 245-60, 2003.
Artigo em Inglês | MEDLINE | ID: mdl-14743977

RESUMO

Many bacterial genomes are under asymmetric mutational pressure which introduces compositional asymmetry into DNA molecule resulting in many biases in coding structure of chromosomes. One of the processes affected by the asymmetry is translocation changing the position of the coding sequence on chromosome in respect to the orientation on the leading and lagging DNA strand. When analysing sets of paralogs in 50 genomes, we found that the number of observed genes which switched their positions on DNA strand is lowest for genomes with the highest DNA asymmetry. However, the number of orthologs which changed DNA strand increases with the phylogenetic distance between the compared genomes. Nevertheless, there is a fraction of coding sequences that stay on the leading strand in all analysed genomes, whereas there are no sequences that stay always on the lagging strand. Since sequences diverge very fast after switching the DNA strand, this bias in mobility of sequences is responsible, in part, for higher divergence rates among some of coding sequences located on the lagging DNA strand.


Assuntos
DNA Bacteriano/genética , Genoma Bacteriano , Cromossomos Bacterianos/genética , Evolução Molecular , RNA Ribossômico 16S/genética , Translocação Genética/genética
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