Dataset Information

Identification and characterization of a ribosome receptor for starvation-induced ribophagy

ABSTRACT: The lysosome degrades and recycles macromolecules, signals to the master growth regulator mTORC1, and is associated with human disease. Here, we performed quantitative proteomic analyses of lysosomes rapidly isolated using the LysoIP method and find that nutrient levels and mTOR dynamically modulate the lysosomal proteome. We focus on NUFIP1, a protein that upon mTORC1 inhibition redistributes from the nucleus to autophagosomes and lysosomes. Upon these conditions, NUFIP1 interacts with ribosomes and delivers them to autophagosomes by directly binding to LC3B. The starvation-induced degradation of ribosomes via autophagy (ribophagy) depends on the capacity of NUFIP1 to bind LC3B and promotes cell survival. We conclude that NUFIP1 is a receptor for the selective autophagy of ribosomes.

INSTRUMENT(S): Orbitrap Fusion Lumos

ORGANISM(S): Homo Sapiens (human)

SUBMITTER: Ivonne Heinze

LAB HEAD: Alessandro Ori

PROVIDER: PXD009084 | Pride | 2018-06-21

REPOSITORIES: Pride

ACCESS DATA

Dataset's files

Source:

			Action	DRS
	170524_IH_DDA_MIT_Lysosomes_Pool01_rep01.kit	Other
	170616_IH_DIA_MIT_Lysosomes_F1.raw	Raw
	170616_IH_DIA_MIT_Lysosomes_F2.raw	Raw
	170616_IH_DIA_MIT_Lysosomes_F3.raw	Raw
	170616_IH_DIA_MIT_Lysosomes_H1.raw	Raw

Items per page:

1 - 5 of 25

Publications

NUFIP1 is a ribosome receptor for starvation-induced ribophagy.

Wyant Gregory A GA Abu-Remaileh Monther M Frenkel Evgeni M EM Laqtom Nouf N NN Dharamdasani Vimisha V Lewis Caroline A CA Chan Sze Ham SH Heinze Ivonne I Ori Alessandro A Sabatini David M DM

Science (New York, N.Y.) 20180426 6390

The lysosome degrades and recycles macromolecules, signals to the master growth regulator mTORC1 [mechanistic target of rapamycin (mTOR) complex 1], and is associated with human disease. We performed quantitative proteomic analyses of rapidly isolated lysosomes and found that nutrient levels and mTOR dynamically modulate the lysosomal proteome. Upon mTORC1 inhibition, NUFIP1 (nuclear fragile X mental retardation-interacting protein 1) redistributes from the nucleus to autophagosomes and lysosome ...[more]

PMID: 29700228

Similar Datasets

Project description:Inflammation is the natural defensive response of the immune system to an injury or infection and is regulated by small molecule mediators triggering different phases of the inflammatory process. In particular, lipid mediators (LM) and cytokines exhibit crucial regulatory functions in the progression and resolution of inflammation. Macrophages play a central role in this process and can adopt distinct phenotypes with specialized functions depending on their microenvironment: inflammatory M1 macrophages drive inflammation by the release of pro-inflammatory cytokines and LMs, like prostaglandins (PG) and leukotrienes (LT), while resolving M2 macrophages promote inflammation resolution and tissue regeneration by production of anti-inflammatory cytokines and specialized pro resolving mediators (SPM). Aging is associated with chronic and unresolved, low-grade inflammation (“inflammaging”) and aging-related dysfunction of macrophages in the resolution of inflammation and tissue maintenance has been reported. Yet, the underlying molecular mechanisms and functional consequences of latter processes remain poorly understood. Here, we show that polarization of peritoneal macrophages (PM) from geriatric mice towards an M2-like phenotype is impaired versus adult mice, resulting in aberrant LM formation and cytokine release. In PMs isolated from adult mice (PM-A) we observed a shift in LM formation from PGs and LTs to SPMs already after 4 h of polarization towards M2 with interleukin (IL) 4. In contrast, PMs from geriatric mice (PM-G) produced mainly LTs and PGs upon polarization. This pattern persists over the course of 48 h of polarization. Proteomic profiling revealed that polarization of PM A towards M2 yields a more distinct phenotype, clearly separated from M1, when compared to PM-G. We observed similar aging-related changes in the lipidome and cytokine profile of spleen, lung and liver tissue from mice. Hence, we hypothesize that during aging macrophage polarization towards M2 is impaired, which in turn drives chronic inflammation and disturbs tissue maintenance. By combining state-of-the art lipidomic and proteomic profiling we aim to uncover new molecular targets for pharmaceutical interventions to improve therapeutic strategies for elderly patients with chronic inflammatory diseases.

Project description:Background: Skeletal muscle crucially depends on motor innervation, and, when damaged, on the resident muscle stem cells (MuSCs). However, the role and function of MuSCs in the context of denervation remains poorly understood. Methods: Alterations of MuSCs and their myofiber niche after denervation were investigated in a surgery-based mouse model of unilateral sciatic nerve transection. FACS-isolated MuSCs were subjected to RNA-sequencing and mass spectrometry for the analysis of intrinsic changes after denervation and in vivo assays, such as Cardiotoxin-induced muscle injury or MuSC transplantation, were performed to assess MuSC functions after denervation. Bioinformatic and histological analyses were conducted to further examine MuSCs and their myofiber niche after denervation. Results: Muscle cross section analysis revealed a significant increase in Pax7 (p-value= 0.0441), Pax7/Ki67 (p-value= 0.0023), MyoD (p-value= 0.0016) and Myog (p-value= 0.0057) positive cells after denervation, illustrating a break of quiescence and commitment to the myogenic lineage. An Omics approach showed profound intrinsic alterations on the mRNA (2613 differentially expressed genes, p-value <0.05) and protein (1096 differentially abundant proteins, q-value <0.05) level of MuSCs 21 days after denervation. Skeletal muscle injury together with denervation surgery caused deregulated regeneration, indicated by the reduced number of proliferating MuSCs and sustained high levels of developmental myosin heavy chain (Sham: 1 % vs DEN: 40 % of all myofibers), at 21 days post-surgery. In a transplantation assay, MuSCs from a denervated host were still able to engraft and fuse to form new myofibers, irrespective of the innervation status of the recipient muscle. Analysis of myofibers revealed not only massive changes in the expression profile (10492 differentially expressed genes, p-value <0.05) after denervation, but it was also shown that secretion of Opn and Tgfb1 from denervated myofibers was increased 30-fold and 6000-fold, respectively. Bioinformatic analyses indicated strong upregulation of gene expression of the transcription factor Junb in MuSCs from denervated muscles (log2 fold change = 3.27). Of interest, Tgfb1 recombinant protein was able to induce Junb gene expression in vitro, demonstrating that myofiber-secreted ligands can induce gene expression changes in MuSCs, which might result in the phenotypes observed after denervation. Conclusion: Skeletal muscle denervation is altering myofiber secretion, causing MuSC activation and profound intrinsic changes, leading to reduced regenerative capacity. As MuSCs possess a remarkable regenerative potential, they might represent a promising target for novel treatment options for neuromuscular disorders and peripheral nerve injuries.

Project description:Metformin is a type 2 diabetes medication which extends life span across species when given from young adulthood onwards; late life effects of metformin are not well understood. Here we used C. elegans to investigate the outcome of metformin treatment initiated late in life. We found that, contrary to young age administration, old age metformin treatment interferes with energy homeostasis and shortens life span by aggravating age-associated mitochondrial dysfunction. Nematode mutants defective in mitochondrial respiration, mitochondrial biogenesis and mitochondrial quality control were highly susceptible to metformin killing already at young age while insulin receptor deficient nematodes carrying healthier mitochondria were protected from late life metformin toxicity. In the mammalian cell culture model of replicative senescence metformin killing correlated with loss of mitochondrial membrane potential and strong reduction of systemic ATP levels. Reduced ATP levels and depletion of lipid stores consistent with energy deficit were observed also in nematodes following late life metformin treatment. At the molecular level young animals responded to metformin by inducing adaptive stress responses and longevity-assurance pathways while old nematodes demonstrated a protein expression signature consistent with lipid turnover and energy deficit. Ectopic ATP supplementation was sufficient to alleviate metformin toxicity in human skin fibroblasts highlighting the key contribution of energy deficit to the detrimental effect of metformin. Also, co-exposure with rapamycin, known to stabilize cellular ATP levels under conditions of mitochondrial failure, significantly reduced metformin-inflicted lethality in both cells and old animals. In summary we uncovered a novel negative synergism between metformin treatment and mitochondrial dysfunction which gains importance late in life and may limit therapeutic benefits of metformin for older patients; these side effects can partially be overcome by co-treatment with agents stabilizing cellular ATP levels such as rapamycin.