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Microbial Cell Factories

Open Access

Targeting expression of expanded polyglutamine proteins to the endoplasmic reticulum or mitochondria prevents their aggregation

  • Erwann Rousseau1,
  • Benjamin Dehay1,
  • Léa Ben-Haïem2,
  • Yvon Trottier2,
  • Michel Morange1 and
  • Anne Bertolotti1
Microbial Cell Factories20065(Suppl 1):S7

Published: 10 October 2006


Endoplasmic ReticulumGlutamineRecombinant ProteinNeurodegenerative DiseaseHigh Tendency

Aggregation of misfolded proteins is a characteristic of several neurodegenerative diseases. The huntingtin amino-terminal fragment with extended polyglutamine repeat forms aggregates closely associated with chaperones both in the cytoplasm and the nucleus. As each cellular compartment contains distinct chaperones and because the molecular mechanisms controlling polyglutamine aggregation are largely unknown, we decided to investigate the influence of different cellular environments on the aggregation of this pathological protein. We found that aggregation of a protein containing a polyglutamine stretch of pathological length is abolished when its expression is targeted to the endoplasmic reticulum. Once retrogradely transported outside of the endoplasmic reticulum, the aggregation-prone polyglutamine containing protein recovers its ability to aggregate. When expressed in the mitochondria, a protein containing 73 glutamines is entirely soluble while the nucleo-cytosolic equivalent has an extremely high tendency to aggregate. Our data imply that polyglutamine aggregation is a property restricted to the nucleo-cytosolic compartment and suggest the existence of compartment-specific co-factors promoting or preventing aggregation of pathological proteins. Implications for recombinant proteins production will be discussed.

Authors’ Affiliations

Laboratoire de Génétique Moléculaire, CNRS UMR8541, Ecole Normale Supérieure, Paris, France
Institut de Génétique et de Biologie Moléculaire et Cellulaire, INSERM-CNRS-Université Louis Pasteur, Illkirch Cedex, France


© Rousseau et al; licensee BioMed Central Ltd. 2006

This article is published under license to BioMed Central Ltd.