Regular Article
Oligomerization of Expanded-Polyglutamine Domain Fluorescent Fusion Proteins in Cultured Mammalian Cells

https://doi.org/10.1006/bbrc.1997.7337Get rights and content

Abstract

Six inherited neurologic diseases, including Huntington's disease, result from the expansion of a CAG domain of the disease genes to produce a domain of more than 40 glutamines in the expressed protein. The mechanism by which expansion of this polyglutamine domain causes disease is unknown. Recent studies demonstrated oligomerization of polyglutamine-domain proteins in mammalian neurons. To study oligomerization of polyglutamine proteins and to identify heterologous protein interactions, varying length polyglutamine-green fluorescent protein fusion proteins were expressed in cultured COS-7 cells. The 19- and 35-glutamine fusion proteins (non-pathologic length) distributed diffusely throughout the cytoplasm. In contrast, 56- and 80-glutamine fusion proteins (pathologic length) formed fibrillar arrays resembling those previously observed in neurons in Huntington's disease and in a transgenic mouse model. These aggregates were intranuclear and intracytoplasmic. Intracytoplasmic aggregates were surrounded by collapsed intermediate filaments. The intermediate filament protein vimentin co-immunoisolated with expanded polyglutamine fusion proteins. This cellular model will expedite investigations into oligomerization of polyglutamine proteins and their interactions with other proteins.

References (30)

  • O. Onodera et al.

    FEBS Letters

    (1996)
  • N.B. Cole et al.

    Curr. Opin. Cell Biol.

    (1995)
  • E. Scherzinger et al.

    Cell

    (1997)
  • S.W. Davies et al.

    Cell

    (1997)
  • M.F. Perutz

    Curr Opin Struct Biol

    (1996)
  • G. Imbert et al.

    Nature Genet.

    (1996)
  • H.L. Paulson et al.

    Annu. Rev. Neurosci.

    (1996)
  • S.M. Pulst et al.

    Nature Genet.

    (1996)
  • K. Sanpei et al.

    Nature Genet.

    (1996)
  • M.F. Perutz et al.

    Proc. Natl. Acad. Sci. U.S.A.

    (1994)
  • K. Stott et al.

    Proc. Natl. Acad. Sci. U.S.A.

    (1995)
  • O. Onodera et al.

    Am J Hum Genet

    (1995)
  • T.J. L'Ecuyer et al.

    Biotechniques

    (1993)
  • K.T. Trevor et al.

    J. Cell. Sci.

    (1995)
  • Cited by (0)

    T. N. ChaseN. S. WexlerA. Barbeau, Eds.

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