RiboTag translatomic profiling of Drosophila oenocytes under aging and induced oxidative stress.

Background: Aging is accompanied with loss of tissue homeostasis and accumulation of cellular damages. As one of the important metabolic centers, liver shows age-related dysregulation of lipid metabolism, impaired detoxification pathway, increased inflammation and oxidative stress response. However, the mechanisms for these age-related changes still remain unclear.

Intestinal IRE1 Is Required for Increased Triglyceride Metabolism and Longer Lifespan under Dietary Restriction.

Dietary restriction (DR) is one of the most robust lifespan-extending interventions in animals. The beneficial effects of DR involve a metabolic adaptation toward increased triglyceride usage. The regulatory mechanism and the tissue specificity of this metabolic switch remain unclear.

Homology-driven genome editing in hematopoietic stem and progenitor cells using ZFN mRNA and AAV6 donors.

Genome editing with targeted nucleases and DNA donor templates homologous to the break site has proven challenging in human hematopoietic stem and progenitor cells (HSPCs), and particularly in the most primitive, long-term repopulating cell population. Here we report that combining electroporation of zinc finger nuclease (ZFN) mRNA with donor template delivery by adeno-associated virus (AAV) serotype 6 vectors directs efficient genome editing in HSPCs, achieving site-specific insertion of a GFP cassette at the CCR5 and AAVS1 loci in mobilized peripheral blood CD34 HSPCs at mean frequencies of 17% and 26%, respectively, and in fetal liver HSPCs at 19% and 43%, respectively. Notably, this approach modified the CD34CD133CD90 cell population, a minor component of CD34 cells that contains long-term repopulating hematopoietic stem cells (HSCs).

Highly efficient homology-driven genome editing in human T cells by combining zinc-finger nuclease mRNA and AAV6 donor delivery.

The adoptive transfer of engineered T cells for the treatment of cancer, autoimmunity, and infectious disease is a rapidly growing field that has shown great promise in recent clinical trials. Nuclease-driven genome editing provides a method in which to precisely target genetic changes to further enhance T cell function in vivo. We describe the development of a highly efficient method to genome edit both primary human CD8 and CD4 T cells by homology-directed repair at a pre-defined site of the genome.

Germline signaling mediates the synergistically prolonged longevity produced by double mutations in daf-2 and rsks-1 in C. elegans.

Inhibition of DAF-2 (insulin-like growth factor 1 [IGF-1] receptor) or RSKS-1 (S6K), key molecules in the insulin/IGF-1 signaling (IIS) and target of rapamycin (TOR) pathways, respectively, extend lifespan in Caenorhabditis elegans. However, it has not been clear how and in which tissues they interact with each other to modulate longevity. Here, we demonstrate that a combination of mutations in daf-2 and rsks-1 produces a nearly 5-fold increase in longevity that is much greater than the sum of single mutations.

hnRNPL and nucleolin bind LINE-1 RNA and function as host factors to modulate retrotransposition.

Long INterspersed Element one (LINE-1, or L1), is a widely distributed, autonomous retrotransposon in mammalian genomes. During retrotransposition, L1 RNA functions first as a dicistronic mRNA and then as a template for cDNA synthesis. Previously, we defined internal ribosome entry sequences (IRESs) upstream of both ORFs (ORF1 and ORF2) in the dicistronic mRNA encoded by mouse L1.

With TOR, less is more: a key role for the conserved nutrient-sensing TOR pathway in aging.

Target of rapamycin (TOR) is an evolutionarily conserved nutrient-sensing protein kinase that regulates growth and metabolism in all eukaryotic cells. Studies in flies, worms, yeast, and mice support the notion that the TOR signaling network modulates aging. TOR is also emerging as a robust mediator of the protective effects of various forms of dietary restriction (DR), which can extend life span and slow the onset of certain age-related diseases across species.

A single amino acid substitution in ORF1 dramatically decreases L1 retrotransposition and provides insight into nucleic acid chaperone activity.

L1 is a ubiquitous interspersed repeated sequence in mammals that achieved its high copy number by autonomous retrotransposition. Individual L1 elements within a genome differ in sequence and retrotransposition activity. Retrotransposition requires two L1-encoded proteins, ORF1p and ORF2p.

Identification and solution structure of a highly conserved C-terminal domain within ORF1p required for retrotransposition of long interspersed nuclear element-1.

Long interspersed nuclear element-1 (LINE-1 or L1) retrotransposons comprise a large fraction of the human and mouse genomes. The mobility of these successful elements requires the protein encoded by open reading frame-1 (ORF1p), which binds single-stranded RNA with high affinity and functions as a nucleic acid chaperone. In this report, we have used limited proteolysis, filter binding, and NMR spectroscopy to characterize the global structure of ORF1p and the three-dimensional structure of a highly conserved RNA binding domain.

The dicistronic RNA from the mouse LINE-1 retrotransposon contains an internal ribosome entry site upstream of each ORF: implications for retrotransposition.

Most eukaryotic mRNAs are monocistronic and translated by cap-dependent initiation. LINE-1 RNA is exceptional because it is naturally dicistronic, encoding two proteins essential for retrotransposition, ORF1p and ORF2p. Here, we show that sequences upstream of ORF1 and ORF2 in mouse L1 function as internal ribosome entry sites (IRESes).

Spatial assembly and RNA binding stoichiometry of a LINE-1 protein essential for retrotransposition.

LINE-1, or L1, is a highly successful retrotransposon in mammals, comprising 17% and 19% of the human and mouse genomes, respectively. L1 retrotransposition and hence amplification requires the protein products of its two open reading frames, ORF1 and ORF2. The sequence of the ORF1 protein (ORF1p) is not related to any protein with known function.

LINE-1 retrotransposition requires the nucleic acid chaperone activity of the ORF1 protein.

LINE-1 is a highly successful, non-LTR retrotransposon that has played a leading role in shaping mammalian genomes. These elements move autonomously through an RNA intermediate using target-primed reverse transcription (TPRT). L1 encodes two essential polypeptides for retrotransposition, the products of its two open reading frames, ORF1 and ORF2.