RESUMO
MAP (mitogen-activated protein) kinases are a family of serine/threonine kinases that have a pivotal role in signal transduction. Here we report the cloning and characterization of a mouse homologue of extracellular-signal-regulated protein kinase (ERK)3. The mouse Erk3 cDNA encodes a predicted protein of 720 residues, which displays 94% identity with human ERK3. Transcription and translation of this cDNA in vitro generates a 100 kDa protein similar to the human gene product ERK3. Immunoblot analysis with an antibody raised against a unique sequence of ERK3 also recognizes a 100 kDa protein in mouse tissues. A single transcript of Erk3 was detected in every adult mouse tissue examined, with the highest expression being found in the brain. Interestingly, expression of Erk3 mRNA is acutely regulated during mouse development, with a peak of expression observed at embryonic day 11. The mouse Erk3 gene was mapped to a single locus on central mouse chromosome 9, adjacent to the dilute mutation locus and in a region syntenic to human chromosome 15q21. Finally, we provide several lines of evidence to support the existence of a unique Erk3 gene product of 100 kDa in mammalian cells.
Assuntos
Proteínas Quinases Dependentes de Cálcio-Calmodulina/química , Proteínas Quinases Dependentes de Cálcio-Calmodulina/genética , Proteínas Quinases Ativadas por Mitógeno , Envelhecimento , Sequência de Aminoácidos , Animais , Sequência de Bases , Western Blotting , Encéfalo/metabolismo , Cromossomos/genética , Clonagem Molecular , Embrião de Mamíferos/metabolismo , Perfilação da Expressão Gênica , Regulação da Expressão Gênica no Desenvolvimento , Marcadores Genéticos/genética , Humanos , Isoenzimas/química , Isoenzimas/genética , Camundongos , Proteína Quinase 6 Ativada por Mitógeno , Dados de Sequência Molecular , Peso Molecular , Mapeamento Físico do Cromossomo , RNA Mensageiro/análise , RNA Mensageiro/genética , Alinhamento de Sequência , Homologia de Sequência de AminoácidosAssuntos
Proteínas Quinases Dependentes de Cálcio-Calmodulina/genética , Mapeamento Cromossômico , Isoenzimas/genética , Proteínas Quinases Ativadas por Mitógeno , Proteínas Tirosina Quinases/genética , Animais , Cromossomos , Feminino , Humanos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Proteína Quinase 1 Ativada por Mitógeno , Proteína Quinase 3 Ativada por MitógenoRESUMO
RFLP analyses were used to characterize several plant populations of Solanum chacoense Bitt. developed to investigate the generation of new S alleles at the self-incompatibility locus. The plant material consisted of two diploid parental lines, their anther culture derived (AC) progenies, their selfed progenies, and their reciprocal F1 hybrids. The RFLP analyses on the AC plants (121 individuals in total) permitted unambiguous identification of their origin. In particular, a distinction between plants originated from reduced (n) or unreduced (2n) microspores could be made. All the AC plants produced by gametic embryogenesis showed distinct RFLP patterns, whereas a number of clones (i.e., plants with identical RFLP patterns) were found among those regenerated via callus. The analyses conducted on the selfed progenies (69 plants) and the F1 hybrids (66 plants) showed only one case of accidental outcross. Segregation studies of the RFLP markers revealed significant deviations from expected Mendelian ratios in both AC-derived populations, as well as in the selfed progenies. Such deviations, however, were rare in the reciprocal F1 hybrids. These results are discussed in relation to the possible presence of genetic sieves operating during AC, illegitimate selfing, or during normal fertilization.
RESUMO
A genomic clone of the S11 allele from the self-incompatibility locus (S locus) in Solanum chacoense Bitt. has been isolated by cross-hybridization to the S. chacoense S13 allele and sequenced. The sequence of the S11 allele contains all the features expected for S genes of the Solanaceae, and S11 expression, as assessed by northern blots and RNA-PCR, was similar to that of other S. chacoense S alleles. The S11 protein sequence shares 95% identity with the phenotypically distinct S13 protein of S. chacoense and is the gametophytic S allele with the highest similarity to an existing allele so far discovered. Only 10 amino acid changes differentiate the mature proteins from these two alleles, which sets a new lower limit to the number of changes that can produce an altered S allele specificity. The amino acid substitutions are not clustered, suggesting that an accumulation of random point mutations can generate S allele diversity. The S11 intron is unusual in that it could be translated in frame with the coding sequence, thus suggesting an additional mechanism for the generation of new S alleles.
