ER storage diseases: A role for ERGIC-53 in controlling the formation and shape of Russell bodies

Laura Mattioli, Tiziana Anelli, Claudio Fagioli, Carlo Tacchetti, Roberto Sitia, Caterina Valetti

Research output: Contribution to journalArticle

Abstract

Owing to the impossibility of reaching the Golgi for secretion or the cytosol for degradation, mutant Ig-μ chains that lack the first constant domain (μΔCH1) accumulate as detergent-insoluble aggregates in dilated endoplasmic reticulum cisternae, called Russell bodies. The presence of similar structures hallmarks many ER storage diseases, but their pathogenic role(s) remain obscure. Exploiting inducible cellular systems, we show here that Russell bodies form when the synthesis of μΔCH1 exceeds the degradation capacity. Condensation occurs in different sub-cellular locations, depending on the interacting molecules present in the host cell: if Ig light chains are co-expressed, detergent-insoluble μΔCH1-light chain oligomers accumulate in large ribosome-coated structures (rough Russell bodies). In absence of light chains, instead, aggregation occurs in smooth tubular vesicles and is controlled by N-glycan-dependent interactions with ER-Golgi intermediate compartment 53 (ERGIC-53). In cells containing smooth Russell bodies, ERGIC-53 co-localizes with μΔCH1 aggregates in a Ca2+, -dependent fashion. Our findings identify a novel ERGIC-53 substrate, and indicate that interactions with light chains or ERGIC-53 seed μΔCH1 condensation in different stations of the early secretory pathway.

Original languageEnglish
Pages (from-to)2532-2541
Number of pages10
JournalJournal of Cell Science
Volume119
Issue number12
DOIs
Publication statusPublished - Jun 15 2006

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Keywords

  • ER associated degradation
  • ER storage diseases
  • ERGIC-53
  • Protein aggregation
  • Russell bodies

ASJC Scopus subject areas

  • Cell Biology

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