SNAT2 transceptor signalling via mTOR: a role in cell growth and proliferation?

Jorge Pinilla, Juan Carlos Aledo, Emma Cwiklinski, Russell Hyde, Peter M. Taylor, Harinder S. Hundal

    Research output: Contribution to journalArticle

    51 Citations (Scopus)

    Abstract

    We have investigated the effect of chronic competitive inhibition of SNAT2 (System A) amino acid (AA) transport, induced by incubation with a saturating dose of a non-metabolisable System A amino acid analogue (Me-AIB), on growth and proliferation of MCF-7 human breast cancer cells in complete culture medium. These cells express Na+- and pH-dependent SNAT2 AA transport and a saturating concentration of Me-AIB (10 mM) competitively inhibits (>90%) AA uptake via SNAT2. Incubation with Me-AIB for up to 5 days progressively reduced cell proliferation (~2-fold) and depleted intracellular concentrations of not only SNAT2 AA substrates but of essential branched chain AAs (e.g. leucine). Surprisingly, total cellular protein was maintained and cells subjected to chronic Me-AIB incubation exhibited a detectable increase in cell size. Analysis of mTOR signalling revealed that, despite a substantial reduction in size of the intracellular AA pool, Me-AIB elevated mTOR-dependent p70S6K1 phosphorylation. Proteomic analysis of TAP-tag purified SNAT2 fusion proteins identified two novel SNAT2-interacting proteins that may potentially function in conjunction with the SNAT2 transceptor to regulate signalling pathways influencing protein turnover and cell growth.
    Original languageEnglish
    Pages (from-to)1289-1299
    Number of pages11
    JournalFrontiers in Bioscience (Elite Edition)
    VolumeE3
    Issue number4
    DOIs
    Publication statusPublished - 1 Jun 2011

    Fingerprint

    Cell proliferation
    Cell growth
    Cell Proliferation
    Amino Acids
    Growth
    Proteins
    Amino Acid Transport Systems
    Essential Amino Acids
    Phosphorylation
    Cell Size
    Leucine
    Proteomics
    Culture Media
    2,2-dimethyl-beta-alanine
    Breast Neoplasms
    Fusion reactions
    Cells
    Substrates

    Keywords

    • Amino acid transporter
    • SLC38A2 protein
    • Cell division
    • Cell proliferation
    • Human
    • Metabolism
    • Polyacrylamide gel electrophoresis
    • Signal transduction
    • Tumor cell line
    • Western blotting

    Cite this

    Pinilla, Jorge ; Aledo, Juan Carlos ; Cwiklinski, Emma ; Hyde, Russell ; Taylor, Peter M. ; Hundal, Harinder S. / SNAT2 transceptor signalling via mTOR : a role in cell growth and proliferation?. In: Frontiers in Bioscience (Elite Edition). 2011 ; Vol. E3, No. 4. pp. 1289-1299.
    @article{9350a20a67044f62a3a154e28cda0c12,
    title = "SNAT2 transceptor signalling via mTOR: a role in cell growth and proliferation?",
    abstract = "We have investigated the effect of chronic competitive inhibition of SNAT2 (System A) amino acid (AA) transport, induced by incubation with a saturating dose of a non-metabolisable System A amino acid analogue (Me-AIB), on growth and proliferation of MCF-7 human breast cancer cells in complete culture medium. These cells express Na+- and pH-dependent SNAT2 AA transport and a saturating concentration of Me-AIB (10 mM) competitively inhibits (>90{\%}) AA uptake via SNAT2. Incubation with Me-AIB for up to 5 days progressively reduced cell proliferation (~2-fold) and depleted intracellular concentrations of not only SNAT2 AA substrates but of essential branched chain AAs (e.g. leucine). Surprisingly, total cellular protein was maintained and cells subjected to chronic Me-AIB incubation exhibited a detectable increase in cell size. Analysis of mTOR signalling revealed that, despite a substantial reduction in size of the intracellular AA pool, Me-AIB elevated mTOR-dependent p70S6K1 phosphorylation. Proteomic analysis of TAP-tag purified SNAT2 fusion proteins identified two novel SNAT2-interacting proteins that may potentially function in conjunction with the SNAT2 transceptor to regulate signalling pathways influencing protein turnover and cell growth.",
    keywords = "Amino acid transporter, SLC38A2 protein, Cell division, Cell proliferation, Human, Metabolism, Polyacrylamide gel electrophoresis, Signal transduction, Tumor cell line, Western blotting",
    author = "Jorge Pinilla and Aledo, {Juan Carlos} and Emma Cwiklinski and Russell Hyde and Taylor, {Peter M.} and Hundal, {Harinder S.}",
    note = "MEDLINE{\circledR} is the source for the citation and abstract of this record.",
    year = "2011",
    month = "6",
    day = "1",
    doi = "10.2741/332",
    language = "English",
    volume = "E3",
    pages = "1289--1299",
    journal = "Frontiers in Bioscience (Elite Edition)",
    issn = "1945-0494",
    publisher = "Frontiers in Bioscience",
    number = "4",

    }

    SNAT2 transceptor signalling via mTOR : a role in cell growth and proliferation? / Pinilla, Jorge; Aledo, Juan Carlos; Cwiklinski, Emma; Hyde, Russell; Taylor, Peter M.; Hundal, Harinder S.

    In: Frontiers in Bioscience (Elite Edition), Vol. E3, No. 4, 01.06.2011, p. 1289-1299.

    Research output: Contribution to journalArticle

    TY - JOUR

    T1 - SNAT2 transceptor signalling via mTOR

    T2 - a role in cell growth and proliferation?

    AU - Pinilla, Jorge

    AU - Aledo, Juan Carlos

    AU - Cwiklinski, Emma

    AU - Hyde, Russell

    AU - Taylor, Peter M.

    AU - Hundal, Harinder S.

    N1 - MEDLINE® is the source for the citation and abstract of this record.

    PY - 2011/6/1

    Y1 - 2011/6/1

    N2 - We have investigated the effect of chronic competitive inhibition of SNAT2 (System A) amino acid (AA) transport, induced by incubation with a saturating dose of a non-metabolisable System A amino acid analogue (Me-AIB), on growth and proliferation of MCF-7 human breast cancer cells in complete culture medium. These cells express Na+- and pH-dependent SNAT2 AA transport and a saturating concentration of Me-AIB (10 mM) competitively inhibits (>90%) AA uptake via SNAT2. Incubation with Me-AIB for up to 5 days progressively reduced cell proliferation (~2-fold) and depleted intracellular concentrations of not only SNAT2 AA substrates but of essential branched chain AAs (e.g. leucine). Surprisingly, total cellular protein was maintained and cells subjected to chronic Me-AIB incubation exhibited a detectable increase in cell size. Analysis of mTOR signalling revealed that, despite a substantial reduction in size of the intracellular AA pool, Me-AIB elevated mTOR-dependent p70S6K1 phosphorylation. Proteomic analysis of TAP-tag purified SNAT2 fusion proteins identified two novel SNAT2-interacting proteins that may potentially function in conjunction with the SNAT2 transceptor to regulate signalling pathways influencing protein turnover and cell growth.

    AB - We have investigated the effect of chronic competitive inhibition of SNAT2 (System A) amino acid (AA) transport, induced by incubation with a saturating dose of a non-metabolisable System A amino acid analogue (Me-AIB), on growth and proliferation of MCF-7 human breast cancer cells in complete culture medium. These cells express Na+- and pH-dependent SNAT2 AA transport and a saturating concentration of Me-AIB (10 mM) competitively inhibits (>90%) AA uptake via SNAT2. Incubation with Me-AIB for up to 5 days progressively reduced cell proliferation (~2-fold) and depleted intracellular concentrations of not only SNAT2 AA substrates but of essential branched chain AAs (e.g. leucine). Surprisingly, total cellular protein was maintained and cells subjected to chronic Me-AIB incubation exhibited a detectable increase in cell size. Analysis of mTOR signalling revealed that, despite a substantial reduction in size of the intracellular AA pool, Me-AIB elevated mTOR-dependent p70S6K1 phosphorylation. Proteomic analysis of TAP-tag purified SNAT2 fusion proteins identified two novel SNAT2-interacting proteins that may potentially function in conjunction with the SNAT2 transceptor to regulate signalling pathways influencing protein turnover and cell growth.

    KW - Amino acid transporter

    KW - SLC38A2 protein

    KW - Cell division

    KW - Cell proliferation

    KW - Human

    KW - Metabolism

    KW - Polyacrylamide gel electrophoresis

    KW - Signal transduction

    KW - Tumor cell line

    KW - Western blotting

    UR - http://www.scopus.com/inward/record.url?scp=80053614972&partnerID=8YFLogxK

    U2 - 10.2741/332

    DO - 10.2741/332

    M3 - Article

    AN - SCOPUS:80053614972

    VL - E3

    SP - 1289

    EP - 1299

    JO - Frontiers in Bioscience (Elite Edition)

    JF - Frontiers in Bioscience (Elite Edition)

    SN - 1945-0494

    IS - 4

    ER -