Project description:Vaccinia virus-related kinase (VRK) is an evolutionarily conserved nuclear protein kinase. VRK-1, the single Caenorhabditis elegans VRK ortholog, functions in cell division and germline proliferation. However, the role of VRK-1 in post-mitotic cells and adult lifespan remain unknown. Here, we show that VRK-1 increases organismal longevity by activating the cellular energy sensor, AMP-activated protein kinase (AMPK), via direct phosphorylation. We found that overexpression of vrk-1 in the soma of adult C. elegans increased lifespan, and conversely, inhibition of vrk-1 decreased lifespan. In addition, vrk-1 was required for longevity conferred by mutations that inhibit C. elegans mitochondrial respiration, which requires AMPK. Notably, VRK-1 directly phosphorylated and up-regulated AMPK in both C. elegans and cultured human cells. Thus, our data show that the somatic nuclear kinase, VRK-1, promotes longevity through AMPK activation, and this function appears to be conserved between C. elegans and humans.
Project description:Transcriptional regulation plays an important role in the control of gene expression during aging. However, translation efficiency likely plays an equally important role in determining protein abundance, but has been relatively under studied in this context. Here we used RNA-seq and ribosome profiling to investigate the role of translational regulation in lifespan extension by CAN1 gene deletion in yeast. Through comparison of the transcriptional and translational changes in cells lacking CAN1 with other long-lived mutants, we were able to identify critical regulatory factors, including transcription factors and mRNA-binding proteins, that coordinate transcriptional and translational responses. Together, our data support a model in which deletion of CAN1 extends replicative lifespan through increased translation of proteins that facilitate cellular response to stress. This study extends our understanding of the importance of translational control in regulating stress resistance and longevity.
Project description:The mitochondrial unfolded protein response (UPRmt) has been associated with long lifespan across metazoans. In Caenorhabditis elegans, mild developmental mitochondrial stress activates UPRmt reporters and extends lifespan. We show that similar developmental stress is necessary and sufficient to extend Drosophila lifespan, and identify Phosphoglycerate Mutase 5 (PGAM5) as a mediator of this response. Developmental mitochondrial stress leads to activation of FoxO, via Apoptosis Signal-regulating Kinase 1 (ASK1) and Jun-N-terminal Kinase (JNK). This activation persists into adulthood and induces a select set of chaperones, many of which have been implicated in lifespan extension in flies. Persistent FoxO activation can be reversed by a high- protein diet in adulthood, through mTORC1 and GCN-2 activity. Accordingly, the observed lifespan extension is prevented on a high-protein diet and in FoxO-null flies. The diet-sensitivity of this pathway has important implications for interventions that seek to engage the UPRmt to improve metabolic health and longevity.
Project description:The AMP-activated protein kinase (AMPK) regulates cellular energy homeostasis by sensing the metabolic status of the cell. AMPK is regulated by phosphorylation and dephosphorylation as a result of changing AMP/ATP levels and by removal of inhibitory ubiquitin residues by USP10. In this context, we identified the GID-complex, an evolutionarily conserved ubiquitin-ligasecomplex (E3), as a negative regulator of AMPK activity. Our data show that the GID-complex targets AMPK for ubiquitination thereby altering its activity. Cells depleted of GID-subunits mimic a state of starvation as shown by increased AMPK activity and autophagic flux as well as reduced MTOR activation. Consistently, gid-genes knockdown in C. elegans results in increased organismal lifespan. This study may contribute to understand metabolic disorders such as type 2 diabetes mellitus and morbid obesity and implements alternative therapeutic approaches to alter AMPK activity.
Project description:gene expression profiling comparing the effect of a direct AMPK activator (GSK621) in human AML cells (MOLM-14 cell line) transduced with a non-targeted CRISPR/Cas9 RNA guide (SCR) or a EIF2AK3 (PERK) - targeting RNA guide
Project description:We investigated the role of AMPK activation in the progression of senescence in HFDPCs. The anti-senescence effects of adenine, a recently identified AMPK activator, were determined in a comparison with AICAR, a pharmacological AMPK activator, in HFDPCs. The results showed that either adenine or AICAR induced phosphorylation of Thr172 of AMPK in HFDPCs. As revealed by microarray analysis, significant changes of gene expression pattern were observed in the high-passage HFDPCs compared with that at lower passage level. A chip study using total RNA recovered from three separate wild-type cultures of Human follicle dermal papilla cells (HFDPCs) and three separate cultures of a triple adenine-treated cells.