RESUMO
Transfection of an activated rat oncogene into NIH3T3 fibroblasts leads to transformation and induction of a metastatic phenotype. To identify genes whose activation might mediate these processes, we used a differential screening strategy. A 1.5-kb transcript is induced fiftyfold, constitutes 1% of ras transformed cell messenger RNA (mRNA) and is the most abundantly induced message in these cells. Our sequence data shows that it encodes murine cathepsin L, a potent collagenolytic and elastinolytic lysosomal enzyme. The murine clone was used to isolate human cathepsin L complementary DNA (cDNA) clones. The complete nucleotide and deduced amino acid sequences of human and murine preprocathepsin L are presented and compared to other papain family cysteine proteinases. Northern analysis shows that both human and murine cathepsin L probes hybridize to a 1.5-kb transcript in several tissues, but also to a 4-kb transcript in human kidney. These clones will facilitate studies of the structure, expression, and function of cathepsin L, including its unexpected upregulation in transformation.
Assuntos
Catepsinas/genética , Precursores Enzimáticos/genética , Transcrição Gênica , Transformação Genética , Sequência de Aminoácidos , Animais , Sequência de Bases , Linhagem Celular Transformada , Clonagem Molecular , DNA/genética , Enzimas de Restrição do DNA , Desoxirribonuclease EcoRI , Fibroblastos , Genes ras , Humanos , Camundongos , Dados de Sequência Molecular , Hibridização de Ácido Nucleico , RNA Mensageiro/genética , TransfecçãoRESUMO
Egr-1 is an early growth response gene that displays fos-like induction kinetics in fibroblasts, epithelial cells, and lymphocytes following mitogenic stimulation. Sequence analysis of murine Egr-1 cDNA predicts a protein with three DNA binding zinc fingers. The human EGR1 gene maps to chromosome 5 (bands 5q23-31). Egr-1 mRNA increases dramatically during cardiac and neural cell differentiation, and following membrane depolarization both in vitro and in vivo. Thus, Egr-1 and c-fos are often coregulated with strikingly similar kinetics. These results, in conjunction with the Egr-1 primary structure, suggest that Egr-1 may function as a transcriptional regulator in diverse biological processes.
Assuntos
Proteínas de Ligação a DNA/genética , Genes Reguladores , Genes , Metaloproteínas/genética , Proto-Oncogenes , Sequência de Aminoácidos , Sequência de Bases , Diferenciação Celular , Divisão Celular , Células Cultivadas , Mapeamento Cromossômico , Cromossomos Humanos Par 5 , Humanos , Cinética , Dados de Sequência Molecular , Ligação Proteica , Zinco/metabolismoRESUMO
Most of the ribosomal RNA genes of the yeast Saccharomyces cerevisiae are about 9 kilobases (kb) in size and encode both the 35S rRNA (processed to produce the 25S, 18S, and 5.8S species) and 5S rRNA. These genes are arranged in a single tandem array of 100 repeats. Below, we present evidence that at the centromere-distal end of this array is a tandem arrangement of a different type of rRNA gene. Each of these repeats is 3.6 kb in length and encodes a single 5S rRNA. The coding sequence of this gene is different from that of the "normal" 5S gene in three positions located at the 3' end of the gene.
