RESUMO
Marine seaweed (Eucheuma sp.) associated strains of Aspergillus flavus and Aspergillus niger were tested for their Cr(VI) tolerance. Both the isolates showed luxuriant growth in different concentrations of Cr(VI), i.e., 25, 50 and 100 ppm. There was no marked variation in the dry weight of control and test isolates, which indicated that both the isolates can tolerate a wide range of hexavalent chromium and their application for bioremediation purpose can be envisaged as XRF data revealed both the isolates accumulated more than 25% of the chromium supplied. A. flavus invariably exhibited higher accumulation potential.
Assuntos
Aspergillus/metabolismo , Cromo/farmacocinética , Aspergillus/efeitos dos fármacos , Cromo/toxicidade , Água do Mar , Alga Marinha , Espectrometria por Raios XRESUMO
Proteins provide the structural framework of a cell and perform the enzymatic activities sustaining DNA replication and energy production. The hormones and growth factors that facilitate organ-to-organ communication are proteins as are the receptors and signaling intermediaries that integrate extracellular stimuli to intracellular action. As such, eukaryotic cells devote tremendous effort and energy to protein synthesis. The enzymes involved in protein synthesis have traditionally been described as cellular housekeepers. This was meant to imply that while they were necessary for cell viability, they were not thought to have a causal role in activating cell differentiation or neoplastic development the way that a transcription factor or hormone receptor might. However, two protein translation factors, protein initiation factor eIF4E and protein elongation factor eEF1A2, have been identified as important human oncogenes. This review summarizes recent work showing that protein initiation and elongation factors have important regulatory roles in cell growth, apoptosis, and tumorigenesis.
Assuntos
Divisão Celular , Fatores de Alongamento de Peptídeos/fisiologia , Fatores de Iniciação de Peptídeos/fisiologia , Biossíntese de Proteínas , Apoptose , Transformação Celular Neoplásica/genética , Humanos , Fatores de Alongamento de Peptídeos/genética , Fatores de Alongamento de Peptídeos/metabolismo , Fatores de Iniciação de Peptídeos/metabolismo , Processamento de Proteína Pós-Traducional , eIF-2 Quinase/metabolismoRESUMO
We have found that EEF1A2, the gene encoding protein elongation factor EEF1A2 (also known as eEF-1 alpha 2), is amplified in 25% of primary ovarian tumors and is highly expressed in approximately 30% of ovarian tumors and established cell lines. We have also demonstrated that EEF1A2 has oncogenic properties: it enhances focus formation, allows anchorage-independent growth and decreases the doubling time of rodent fibroblasts. In addition, EEF1A2 expression made NIH3T3 fibroblasts tumorigenic and increased the growth rate of ES-2 ovarian carcinoma cells xenografted in nude mice. Thus, EEF1A2 and the process of protein elongation are likely to be critical in the development of ovarian cancer.
