Dissociation of Mitogenesis and Transforming Activity by C-Terminal Truncation of the Insulin-like Growth Factor-I Receptor

Ewa Surmacz, Christian Sell, Jennifer Swantek, Hisanori Kato, Charles Roberts, Derek LeRoith, Renato Baserga

    Research output: Contribution to journalArticle

    69 Citations (Scopus)

    Abstract

    We have investigated the mitogenic and transforming ability of an IGF-I receptor with a 108-amino-acid C-terminal truncation in R cells, which are 3T3-like cells derived from mouse embryos in which the IGF-I receptor genes have been disrupted by targeted homologous recombination. R cells stably transfected with expression plasmids encoding either a wild-type or a truncated human IGF-I receptor were capable growing in serum-free medium supplemented solely with IGF-I. This response was observed over a wide range of receptor levels. R cells overexpressing the wild-type IGF-I receptor also formed colonies in soft agar, and colony formation was augmented by coexpression of the SV40 large T antigen. However, all the examined clones of R-cells expressing the truncated IGF-I receptor exhibited a dramatically impaired ability to grow in soft agar, even in the presence of the T antigen. The inability to Form colonies in soft agar was not due to a quantitative impairment of signal transduction, because: (1) SV40-transformed cells with a physiological level of the wild-type IGF-I receptor did not respond to IGF-I with cell proliferation, but grew in soft agar; (2) R- cells stably transfected with both a truncated receptor and T antigen, on the contrary, responded with mitogenesis to IGF-I but could not form colonies in soft agar; (3) some clones with the truncated receptor expressed levels of receptor roughly 100-fold the level of wild-type cells; and (4) several parameters of IGF-I receptor signal transduction were not impaired in cells stably transfected with a truncated receptor. Furthermore, overexpression of an activated ras in cells with the truncated IGF-IR did not restore their ability to proliferate under anchorage-independent conditions. We conclude that the last 108 amino acids of tile IGF-I receptor are not essential for a mitogenic response to IGF-I, but are required for transformation (as assessed by the ability to grow in soft agar), indicating that these two functions can be dissociated at an intramolecular level. Moreover, although ras (activated) certainly plays a role in transformation, the transforming activity of the IGF-IR also requires signaling elements that are ras-independent.

    Original languageEnglish (US)
    Pages (from-to)370-380
    Number of pages11
    JournalExperimental Cell Research
    Volume218
    Issue number1
    DOIs
    StatePublished - May 1995

    Fingerprint

    IGF Type 1 Receptor
    Agar
    Insulin-Like Growth Factor I
    Viral Tumor Antigens
    Signal Transduction
    Clone Cells
    Polyomavirus Transforming Antigens
    Amino Acids
    3T3 Cells
    Homologous Recombination
    Serum-Free Culture Media
    Plasmids
    Embryonic Structures
    Cell Proliferation

    ASJC Scopus subject areas

    • Cell Biology

    Cite this

    Dissociation of Mitogenesis and Transforming Activity by C-Terminal Truncation of the Insulin-like Growth Factor-I Receptor. / Surmacz, Ewa; Sell, Christian; Swantek, Jennifer; Kato, Hisanori; Roberts, Charles; LeRoith, Derek; Baserga, Renato.

    In: Experimental Cell Research, Vol. 218, No. 1, 05.1995, p. 370-380.

    Research output: Contribution to journalArticle

    Surmacz, Ewa ; Sell, Christian ; Swantek, Jennifer ; Kato, Hisanori ; Roberts, Charles ; LeRoith, Derek ; Baserga, Renato. / Dissociation of Mitogenesis and Transforming Activity by C-Terminal Truncation of the Insulin-like Growth Factor-I Receptor. In: Experimental Cell Research. 1995 ; Vol. 218, No. 1. pp. 370-380.
    @article{1bbeb18dbe894ced86a2d50eb6b292d9,
    title = "Dissociation of Mitogenesis and Transforming Activity by C-Terminal Truncation of the Insulin-like Growth Factor-I Receptor",
    abstract = "We have investigated the mitogenic and transforming ability of an IGF-I receptor with a 108-amino-acid C-terminal truncation in R cells, which are 3T3-like cells derived from mouse embryos in which the IGF-I receptor genes have been disrupted by targeted homologous recombination. R cells stably transfected with expression plasmids encoding either a wild-type or a truncated human IGF-I receptor were capable growing in serum-free medium supplemented solely with IGF-I. This response was observed over a wide range of receptor levels. R cells overexpressing the wild-type IGF-I receptor also formed colonies in soft agar, and colony formation was augmented by coexpression of the SV40 large T antigen. However, all the examined clones of R-cells expressing the truncated IGF-I receptor exhibited a dramatically impaired ability to grow in soft agar, even in the presence of the T antigen. The inability to Form colonies in soft agar was not due to a quantitative impairment of signal transduction, because: (1) SV40-transformed cells with a physiological level of the wild-type IGF-I receptor did not respond to IGF-I with cell proliferation, but grew in soft agar; (2) R- cells stably transfected with both a truncated receptor and T antigen, on the contrary, responded with mitogenesis to IGF-I but could not form colonies in soft agar; (3) some clones with the truncated receptor expressed levels of receptor roughly 100-fold the level of wild-type cells; and (4) several parameters of IGF-I receptor signal transduction were not impaired in cells stably transfected with a truncated receptor. Furthermore, overexpression of an activated ras in cells with the truncated IGF-IR did not restore their ability to proliferate under anchorage-independent conditions. We conclude that the last 108 amino acids of tile IGF-I receptor are not essential for a mitogenic response to IGF-I, but are required for transformation (as assessed by the ability to grow in soft agar), indicating that these two functions can be dissociated at an intramolecular level. Moreover, although ras (activated) certainly plays a role in transformation, the transforming activity of the IGF-IR also requires signaling elements that are ras-independent.",
    author = "Ewa Surmacz and Christian Sell and Jennifer Swantek and Hisanori Kato and Charles Roberts and Derek LeRoith and Renato Baserga",
    year = "1995",
    month = "5",
    doi = "10.1006/excr.1995.1168",
    language = "English (US)",
    volume = "218",
    pages = "370--380",
    journal = "Experimental Cell Research",
    issn = "0014-4827",
    publisher = "Academic Press Inc.",
    number = "1",

    }

    TY - JOUR

    T1 - Dissociation of Mitogenesis and Transforming Activity by C-Terminal Truncation of the Insulin-like Growth Factor-I Receptor

    AU - Surmacz, Ewa

    AU - Sell, Christian

    AU - Swantek, Jennifer

    AU - Kato, Hisanori

    AU - Roberts, Charles

    AU - LeRoith, Derek

    AU - Baserga, Renato

    PY - 1995/5

    Y1 - 1995/5

    N2 - We have investigated the mitogenic and transforming ability of an IGF-I receptor with a 108-amino-acid C-terminal truncation in R cells, which are 3T3-like cells derived from mouse embryos in which the IGF-I receptor genes have been disrupted by targeted homologous recombination. R cells stably transfected with expression plasmids encoding either a wild-type or a truncated human IGF-I receptor were capable growing in serum-free medium supplemented solely with IGF-I. This response was observed over a wide range of receptor levels. R cells overexpressing the wild-type IGF-I receptor also formed colonies in soft agar, and colony formation was augmented by coexpression of the SV40 large T antigen. However, all the examined clones of R-cells expressing the truncated IGF-I receptor exhibited a dramatically impaired ability to grow in soft agar, even in the presence of the T antigen. The inability to Form colonies in soft agar was not due to a quantitative impairment of signal transduction, because: (1) SV40-transformed cells with a physiological level of the wild-type IGF-I receptor did not respond to IGF-I with cell proliferation, but grew in soft agar; (2) R- cells stably transfected with both a truncated receptor and T antigen, on the contrary, responded with mitogenesis to IGF-I but could not form colonies in soft agar; (3) some clones with the truncated receptor expressed levels of receptor roughly 100-fold the level of wild-type cells; and (4) several parameters of IGF-I receptor signal transduction were not impaired in cells stably transfected with a truncated receptor. Furthermore, overexpression of an activated ras in cells with the truncated IGF-IR did not restore their ability to proliferate under anchorage-independent conditions. We conclude that the last 108 amino acids of tile IGF-I receptor are not essential for a mitogenic response to IGF-I, but are required for transformation (as assessed by the ability to grow in soft agar), indicating that these two functions can be dissociated at an intramolecular level. Moreover, although ras (activated) certainly plays a role in transformation, the transforming activity of the IGF-IR also requires signaling elements that are ras-independent.

    AB - We have investigated the mitogenic and transforming ability of an IGF-I receptor with a 108-amino-acid C-terminal truncation in R cells, which are 3T3-like cells derived from mouse embryos in which the IGF-I receptor genes have been disrupted by targeted homologous recombination. R cells stably transfected with expression plasmids encoding either a wild-type or a truncated human IGF-I receptor were capable growing in serum-free medium supplemented solely with IGF-I. This response was observed over a wide range of receptor levels. R cells overexpressing the wild-type IGF-I receptor also formed colonies in soft agar, and colony formation was augmented by coexpression of the SV40 large T antigen. However, all the examined clones of R-cells expressing the truncated IGF-I receptor exhibited a dramatically impaired ability to grow in soft agar, even in the presence of the T antigen. The inability to Form colonies in soft agar was not due to a quantitative impairment of signal transduction, because: (1) SV40-transformed cells with a physiological level of the wild-type IGF-I receptor did not respond to IGF-I with cell proliferation, but grew in soft agar; (2) R- cells stably transfected with both a truncated receptor and T antigen, on the contrary, responded with mitogenesis to IGF-I but could not form colonies in soft agar; (3) some clones with the truncated receptor expressed levels of receptor roughly 100-fold the level of wild-type cells; and (4) several parameters of IGF-I receptor signal transduction were not impaired in cells stably transfected with a truncated receptor. Furthermore, overexpression of an activated ras in cells with the truncated IGF-IR did not restore their ability to proliferate under anchorage-independent conditions. We conclude that the last 108 amino acids of tile IGF-I receptor are not essential for a mitogenic response to IGF-I, but are required for transformation (as assessed by the ability to grow in soft agar), indicating that these two functions can be dissociated at an intramolecular level. Moreover, although ras (activated) certainly plays a role in transformation, the transforming activity of the IGF-IR also requires signaling elements that are ras-independent.

    UR - http://www.scopus.com/inward/record.url?scp=0029044416&partnerID=8YFLogxK

    UR - http://www.scopus.com/inward/citedby.url?scp=0029044416&partnerID=8YFLogxK

    U2 - 10.1006/excr.1995.1168

    DO - 10.1006/excr.1995.1168

    M3 - Article

    VL - 218

    SP - 370

    EP - 380

    JO - Experimental Cell Research

    JF - Experimental Cell Research

    SN - 0014-4827

    IS - 1

    ER -