RESUMO
BACKGROUND/AIMS: Regulation of mRNA translation is central to protein homeostasis and is optimized for speed and accuracy. Spontaneous recoding events occur virtually at any codon but at very low frequency and are commonly assumed to increase as the cell ages. METHODS: Here, we leveraged the polyglutamine(polyQ)-frameshifting model of huntingtin exon 1 with CAG repeat length in the pathological range (Htt51Q), which undergoes enhanced non-programmed translational -1 frameshifting. RESULTS: In body muscle cells of Caenorhabditis elegans, -1 frameshifting occured at the onset of expression of the zero-frame product, correlated with mRNA level of the non-frameshifted expression and formed aggregates correlated with reduced motility in C. elegans. Spontaneous frameshifting was modulated by IFG-1, the homologue of the nutrient-responsive eukaryotic initiation factor 4G (eIF4G), under normal growth conditions and NSUN-5, a conserved ribosomal RNA methyltransferase, under osmotic stress. CONCLUSION: Our results suggest that frameshifting and aggregation occur at even early stages of development and, because of their intrinsic stability, may persist and accelerate the onset of age-related proteinopathies.
Assuntos
Proteínas de Caenorhabditis elegans , Caenorhabditis elegans , Mutação da Fase de Leitura , Proteína Huntingtina , Doença de Huntington , Expansão das Repetições de Trinucleotídeos , Animais , Caenorhabditis elegans/genética , Caenorhabditis elegans/metabolismo , Proteínas de Caenorhabditis elegans/genética , Proteínas de Caenorhabditis elegans/metabolismo , Modelos Animais de Doenças , Éxons , Humanos , Proteína Huntingtina/genética , Proteína Huntingtina/metabolismo , Doença de Huntington/genética , Doença de Huntington/metabolismo , Agregação Patológica de Proteínas/genética , Agregação Patológica de Proteínas/metabolismoRESUMO
Arylethynylchromium(III) complexes of the form trans-[Cr(cyclam)(CCC(6)H(4)R)(2)]OTf (where cyclam = 1,4,8,11-tetraazacyclotetradecane, R = H, CH(3), or CF(3) in the para position, and OTf = trifluoromethanesulfonate) have been prepared and characterized by IR spectroscopy and X-ray diffraction. The complexes are emissive with excited-state lifetimes in a deoxygenated fluid solution between 200 and 300 micros.