1. Cell Biology

Intracellular sphingosine releases calcium from lysosomes

  1. Doris Höglinger
  2. Per Haberkant
  3. Auxiliadora Aguilera-Romero
  4. Howard Riezman
  5. Forbes D Porter
  6. Frances M Platt
  7. Antony Galione
  8. Carsten Schultz  Is a corresponding author
  1. European Molecular Biology Laboratory, Germany
  2. University of Geneva, Switzerland
  3. National Institutes of Health, United States
  4. University of Oxford, United Kingdom
https://doi.org/10.7554/eLife.10616
Share this article
Cite this article
  1. Doris Höglinger
  2. Per Haberkant
  3. Auxiliadora Aguilera-Romero
  4. Howard Riezman
  5. Forbes D Porter
  6. Frances M Platt
  7. Antony Galione
  8. Carsten Schultz
(2015)
Intracellular sphingosine releases calcium from lysosomes
eLife 4:e10616.
https://doi.org/10.7554/eLife.10616
  2. Download BibTeX
  3. Download .RIS

Abstract

To elucidate new functions of sphingosine (Sph), we demonstrate that the spontaneous elevation of intracellular Sph levels via caged Sph leads to a significant and transient calcium release from acidic stores that is independent of sphingosine 1-phosphate, extracellular and ER calcium levels. This photo-induced Sph-driven calcium release requires the two-pore channel 1 (TPC1) residing on endosomes and lysosomes. Further, uncaging of Sph leads to the translocation of the autophagy-relevant transcription factor EB (TFEB) to the nucleus specifically after lysosomal calcium release. We confirm that Sph accumulates in endosomes/lysosomes of cells derived from Niemann-Pick disease type C (NPC) patients and demonstrate a greatly reduced calcium release upon Sph uncaging. We conclude that sphingosine is a positive regulator of calcium release from acidic stores and that understanding the interplay between Sph homeostasis, calcium signaling and autophagy will be crucial in developing new therapies for lipid storage disorders such as NPC.

Article and author information

Author details

  1. Doris Höglinger

    Cell Biology and Biophysics Unit, European Molecular Biology Laboratory, Heidelberg, Germany
    Competing interests
    The authors declare that no competing interests exist.

  2. Per Haberkant

    Cell Biology and Biophysics Unit, European Molecular Biology Laboratory, Heidelberg, Germany
    Competing interests
    The authors declare that no competing interests exist.

  3. Auxiliadora Aguilera-Romero

    Department of Biochemistry, University of Geneva, Geneva, Switzerland
    Competing interests
    The authors declare that no competing interests exist.

  4. Howard Riezman

    Department of Biochemistry, University of Geneva, Geneva, Switzerland
    Competing interests
    The authors declare that no competing interests exist.

  5. Forbes D Porter

    Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, United States
    Competing interests
    The authors declare that no competing interests exist.

  6. Frances M Platt

    Department of Pharmacology, University of Oxford, Oxford, United Kingdom
    Competing interests
    The authors declare that no competing interests exist.

  7. Antony Galione

    Department of Pharmacology, University of Oxford, Oxford, United Kingdom
    Competing interests
    The authors declare that no competing interests exist.

  8. Carsten Schultz

    Cell Biology and Biophysics Unit, European Molecular Biology Laboratory, Heidelberg, Germany
    For correspondence
    schultz@embl.de
    Competing interests
    The authors declare that no competing interests exist.

Reviewing Editor

  1. Suzanne R Pfeffer, Stanford University School of Medicine, United States

Version history

  1. Received: August 4, 2015
  2. Accepted: November 27, 2015
  3. Accepted Manuscript published: November 27, 2015 (version 1)
  4. Version of Record published: January 27, 2016 (version 2)

Copyright

This is an open-access article, free of all copyright, and may be freely reproduced, distributed, transmitted, modified, built upon, or otherwise used by anyone for any lawful purpose. The work is made available under the Creative Commons CC0 public domain dedication.

Metrics

  • 5,532
    views
  • 1,404
    downloads
  • 110
    citations

Views, downloads and citations are aggregated across all versions of this paper published by eLife.

Download links

A two-part list of links to download the article, or parts of the article, in various formats.

Downloads (link to download the article as PDF)

Open citations (links to open the citations from this article in various online reference manager services)

Cite this article (links to download the citations from this article in formats compatible with various reference manager tools)

  1. Doris Höglinger
  2. Per Haberkant
  3. Auxiliadora Aguilera-Romero
  4. Howard Riezman
  5. Forbes D Porter
  6. Frances M Platt
  7. Antony Galione
  8. Carsten Schultz
(2015)
Intracellular sphingosine releases calcium from lysosomes
eLife 4:e10616.
https://doi.org/10.7554/eLife.10616

Share this article

https://doi.org/10.7554/eLife.10616

Categories and tags

Research organisms

Further reading

    1. Biochemistry and Chemical Biology
    2. Cell Biology

    MEMO1 binds iron and modulates iron homeostasis in cancer cells

    Natalia Dolgova, Eva-Maria E Uhlemann ... Oleg Y Dmitriev
    Research Article Updated

    Mediator of ERBB2-driven cell motility 1 (MEMO1) is an evolutionary conserved protein implicated in many biological processes; however, its primary molecular function remains unknown. Importantly, MEMO1 is overexpressed in many types of cancer and was shown to modulate breast cancer metastasis through altered cell motility. To better understand the function of MEMO1 in cancer cells, we analyzed genetic interactions of MEMO1 using gene essentiality data from 1028 cancer cell lines and found multiple iron-related genes exhibiting genetic relationships with MEMO1. We experimentally confirmed several interactions between MEMO1 and iron-related proteins in living cells, most notably, transferrin receptor 2 (TFR2), mitoferrin-2 (SLC25A28), and the global iron response regulator IRP1 (ACO1). These interactions indicate that cells with high-MEMO1 expression levels are hypersensitive to the disruptions in iron distribution. Our data also indicate that MEMO1 is involved in ferroptosis and is linked to iron supply to mitochondria. We have found that purified MEMO1 binds iron with high affinity under redox conditions mimicking intracellular environment and solved MEMO1 structures in complex with iron and copper. Our work reveals that the iron coordination mode in MEMO1 is very similar to that of iron-containing extradiol dioxygenases, which also display a similar structural fold. We conclude that MEMO1 is an iron-binding protein that modulates iron homeostasis in cancer cells.

    1. Cell Biology

    Pigmentation level of human iPSC-derived RPE does not indicate a specific gene expression profile

    Yoko Nakai-Futatsugi, Jianshi Jin ... Masayo Takahashi
    Research Article

    Retinal pigment epithelium (RPE) cells show heterogeneous levels of pigmentation when cultured in vitro. To know whether their color in appearance is correlated with the function of the RPE, we analyzed the color intensities of human-induced pluripotent stem cell-derived RPE cells (iPSC-RPE) together with the gene expression profile at the single-cell level. For this purpose, we utilized our recent invention, Automated Live imaging and cell Picking System (ALPS), which enabled photographing each cell before RNA-sequencing analysis to profile the gene expression of each cell. While our iPSC-RPE were categorized into four clusters by gene expression, the color intensity of iPSC-RPE did not project any specific gene expression profiles. We reasoned this by less correlation between the actual color and the gene expressions that directly define the level of pigmentation, from which we hypothesized the color of RPE cells may be a temporal condition not strongly indicating the functional characteristics of the RPE.

    1. Cancer Biology
    2. Cell Biology

    CYRI-B mediated macropinocytosis drives metastasis via lysophosphatidic acid receptor uptake

    Savvas Nikolaou, Amelie Juin ... Laura M Machesky
    Research Article

    Pancreatic ductal adenocarcinoma carries a dismal prognosis, with high rates of metastasis and few treatment options. Hyperactivation of KRAS in almost all tumours drives RAC1 activation, conferring enhanced migratory and proliferative capacity as well as macropinocytosis. Macropinocytosis is well understood as a nutrient scavenging mechanism, but little is known about its functions in trafficking of signaling receptors. We find that CYRI-B is highly expressed in pancreatic tumours in a mouse model of KRAS and p53-driven pancreatic cancer. Deletion of Cyrib (the gene encoding CYRI-B protein) accelerates tumourigenesis, leading to enhanced ERK and JNK-induced proliferation in precancerous lesions, indicating a potential role as a buffer of RAC1 hyperactivation in early stages. However, as disease progresses, loss of CYRI-B inhibits metastasis. CYRI-B depleted tumour cells show reduced chemotactic responses to lysophosphatidic acid, a major driver of tumour spread, due to impaired macropinocytic uptake of the lysophosphatidic acid receptor-1. Overall, we implicate CYRI-B as a mediator of growth and signaling in pancreatic cancer, providing new insights into pathways controlling metastasis.