When it was discovered in the 1970s as a ubiquitous protein, ubiquitin, a 76-aminoacid peptide, had no assigned function. It was not until later that ubiquitin was found to be a necessary cofactor in a vital cellular ...When it was discovered in the 1970s as a ubiquitous protein, ubiquitin, a 76-aminoacid peptide, had no assigned function. It was not until later that ubiquitin was found to be a necessary cofactor in a vital cellular process： the degradation of proteins. Work by Avram Hershko, Aaron Ciechanover, and Irwin Rose （for which they received the 2004 Nobel Prize in Chemistry） showed that the covalent attachment of ubiquitin provide pro-teins with a tag that dispatches them to the proteasome, the main cell degradation machinery （Ciechanover 2012）. Subsequent work, has revealed that ubiquitin belongs to a broader family of ubiquitin-like proteins that can modify not only protein stability, but also subcellular localization and function.展开更多
In recent developments in chemistry and genetic engineering, the humble researcher dealing with the origin of life finds her（him）self in a grey area of tackling something that even does not yet have a clear definiti...In recent developments in chemistry and genetic engineering, the humble researcher dealing with the origin of life finds her（him）self in a grey area of tackling something that even does not yet have a clear definition agreed upon. A series of chemical steps is described to be considered as the life-nonlife transition, if one adheres to the minimalistic definition： life is self-reproduction with variations. The fully artificial RNA system chosen for the exploration corresponds sequence-wise to the reconstructed initial triplet repeats, presumably corresponding to the earliest protein-coding molecules. The demonstrated occurrence of the mismatches （variations） in otherwise complementary syntheses （＂self-reproduction＂）, in this RNA system, opens an experimental and conceptual perspective to explore the origin of life （and its definition）, on the apparent edge of the origin.展开更多
基金supported by an Executive Programme of Scientific and Technological Cooperation between Italy and China 2010-2012the National Science Foundation of China 31030047
文摘When it was discovered in the 1970s as a ubiquitous protein, ubiquitin, a 76-aminoacid peptide, had no assigned function. It was not until later that ubiquitin was found to be a necessary cofactor in a vital cellular process： the degradation of proteins. Work by Avram Hershko, Aaron Ciechanover, and Irwin Rose （for which they received the 2004 Nobel Prize in Chemistry） showed that the covalent attachment of ubiquitin provide pro-teins with a tag that dispatches them to the proteasome, the main cell degradation machinery （Ciechanover 2012）. Subsequent work, has revealed that ubiquitin belongs to a broader family of ubiquitin-like proteins that can modify not only protein stability, but also subcellular localization and function.
基金supported by Grant ASI-INAF n. I/015/07/0 "Esplorazione del Sistema Solare"
文摘In recent developments in chemistry and genetic engineering, the humble researcher dealing with the origin of life finds her（him）self in a grey area of tackling something that even does not yet have a clear definition agreed upon. A series of chemical steps is described to be considered as the life-nonlife transition, if one adheres to the minimalistic definition： life is self-reproduction with variations. The fully artificial RNA system chosen for the exploration corresponds sequence-wise to the reconstructed initial triplet repeats, presumably corresponding to the earliest protein-coding molecules. The demonstrated occurrence of the mismatches （variations） in otherwise complementary syntheses （＂self-reproduction＂）, in this RNA system, opens an experimental and conceptual perspective to explore the origin of life （and its definition）, on the apparent edge of the origin.
