Assuntos
Portador Sadio , Infecções por HTLV-I , Vírus Linfotrópico T Tipo 1 Humano , Leucemia-Linfoma de Células T do Adulto/etiologia , Leucemia-Linfoma de Células T do Adulto/terapia , Transplante de Células-Tronco de Sangue Periférico , Afasia/etiologia , Encéfalo/patologia , Feminino , Humanos , Imunocompetência , Imageamento por Ressonância Magnética , Pessoa de Meia-IdadeRESUMO
We analyzed the proteome of a crenararchaeon, Aeropyrum pernix K1, by using the following four methods: (i) two-dimensional PAGE followed by MALDI-TOF MS, (ii) one-dimensional SDS-PAGE in combination with two-dimensional LC-MS/MS, (iii) multidimensional LC-MS/MS, and (iv) two-dimensional PAGE followed by amino-terminal amino acid sequencing. These methods were found to be complementary to each other, and biases in the data obtained in one method could largely be compensated by the data obtained in the other methods. Consequently a total of 704 proteins were successfully identified, 134 of which were unique to A. pernix K1, and 19 were not described previously in the genomic annotation. We found that the original annotation of the genomic data of this archaeon was not adequate in particular with respect to proteins of 10-20 kDa in size, many of which were described as hypothetical. Furthermore the amino-terminal amino acid sequence analysis indicated that surprisingly the translation of 52% of their genes starts with TTG in contrast to ATG (28%) and GTG (20%). Thus, A. pernix K1 is the first example of an organism in which TTG is the most predominant translational initiation codon.
Assuntos
Aeropyrum/química , Proteoma/análise , Proteoma/química , Proteômica , Aerobiose , Aeropyrum/classificação , Sequência de Aminoácidos , Proteínas Arqueais/química , Composição de Bases/genética , Cromatografia Líquida , Códon/genética , Eletroforese em Gel Bidimensional , Eletroforese em Gel de Poliacrilamida , Interações Hidrofóbicas e Hidrofílicas , Ponto Isoelétrico , Espectrometria de Massas , Dados de Sequência Molecular , Peso Molecular , Fases de Leitura Aberta/genética , Iniciação Traducional da Cadeia Peptídica/genéticaRESUMO
By analyzing 1,780,295 5'-end sequences of human full-length cDNAs derived from 164 kinds of oligo-cap cDNA libraries, we identified 269,774 independent positions of transcriptional start sites (TSSs) for 14,628 human RefSeq genes. These TSSs were clustered into 30,964 clusters that were separated from each other by more than 500 bp and thus are very likely to constitute mutually distinct alternative promoters. To our surprise, at least 7674 (52%) human RefSeq genes were subject to regulation by putative alternative promoters (PAPs). On average, there were 3.1 PAPs per gene, with the composition of one CpG-island-containing promoter per 2.6 CpG-less promoters. In 17% of the PAP-containing loci, tissue-specific use of the PAPs was observed. The richest tissue sources of the tissue-specific PAPs were testis and brain. It was also intriguing that the PAP-containing promoters were enriched in the genes encoding signal transduction-related proteins and were rarer in the genes encoding extracellular proteins, possibly reflecting the varied functional requirement for and the restricted expression of those categories of genes, respectively. The patterns of the first exons were highly diverse as well. On average, there were 7.7 different splicing types of first exons per locus partly produced by the PAPs, suggesting that a wide variety of transcripts can be achieved by this mechanism. Our findings suggest that use of alternate promoters and consequent alternative use of first exons should play a pivotal role in generating the complexity required for the highly elaborated molecular systems in humans.