Abstract
Dilysine motifs in cytoplasmic domains of transmembrane proteins are signals for their continuous retrieval from the Golgi back to the endoplasmic reticulum (ER). We describe a system to assess retrieval to the ER in yeast cells making use of a dilysine-tagged Ste2 protein. Whereas retrieval was unaffected in most sec mutants tested (sec7, sec12, sec13, sec16, sec17, sec18, sec19, sec22, and sec23), a defect in retrieval was observed in previously characterized coatomer mutants (sec21-1, sec27-1), as well as in newly isolated retrieval mutants (sec21-2, ret1-1). RET1 was cloned by complementation and found to encode the α subunit of coatomer. While temperature-sensitive for growth, the newly isolated coatomer mutants exhibited a very modest defect in secretion at the nonpermissive temperature. Coatomer from β'-COP (sec27-1) and α-COP (ret1-1) mutants, but not from γ-COP (sec21) mutants, had lost the ability to bind dilysine motifs in vitro. Together, these results suggest that coatomer plays an essential role in retrograde Golgi-to-ER transport and retrieval of dilysine-tagged proteins back to the ER.
| Original language | English |
|---|---|
| Journal | Cell |
| Volume | 79 |
| Issue number | 7 |
| Pages (from-to) | 1199-1207 |
| Number of pages | 9 |
| ISSN | 0092-8674 |
| DOIs | |
| Publication status | Published - 30.12.1994 |
Funding
fiths, Randy Schekman, and Jose A. Garcia-San2 for critical reading of the manuscript, and David Avila, Peg Scott, Fabienne Crausaz, and Thomas Aust for technical assistance. The laboratory of H. Ft. was supported by a grant from the Swiss National Science Foundation, the laboratory of S. D. E. by a grant from the National Institutes of Health and by the Howard Hughes Medical Institute, and the laboratory of Randy Schekman (R. D.) by the Howard Hughes Medical Institute. R. D. was supported by a fellowship from the European Molecular BiologyOrganization.The Base1 Instituteforlmmunologywasfounded and is supported by F. Hoffman-LaRoche and Company, Limited, CH-4002 Basel, Switzerland.
Research Areas and Centers
- Academic Focus: Center for Infection and Inflammation Research (ZIEL)
