| Title: | Analysis of the localization of STE6/CFTR chimeras in a Saccharomyces cerevisiae model for the cystic fibrosis defect CFTR delta F508 |
| Author(s): | Paddon C; Loayza D; Vangelista L; Solari R; Michaelis S; |
| Address: | "Cell Biology Unit, Glaxo Wellcome Medicines Research Centre, Stevenage, Hertfordshire, England" |
| DOI: | 10.1046/j.1365-2958.1996.444973.x |
| ISSN/ISBN: | 0950-382X (Print) 0950-382X (Linking) |
| Abstract: | "The use of yeast as a model system to study mammalian proteins is attractive, because yeast genetic tools can be utilized if a suitable phenotype is created. STE6, the Saccharomyces cerevisiae a-factor mating pheromone transporter, and CFTR, the mammalian cystic fibrosis transmembrane conductance regulator, are both members of the ATP binding cassette (ABC) superfamily. Teem et al. (1993) described a yeast model for studying a mutant form of the cystic fibrosis protein, CFTR delta F508. The model involved expression of a chimeric molecule in which a portion of yeast STE6 was replaced with the corresponding region from mammalian CFTR. The STE6/CFTR chimera complemented a ste6 mutant strain for mating, indicating that it could export a-factor. However, mating efficiency was dramatically reduced upon introduction of delta F508, providing a yeast phenotype for this mutation. In human cells, the delta F508 mutation results in retention of CFTR in the endoplasmic reticulum (ER), and possibly in reduction of its chloride-channel activity. Here we examine the basis for the differences in STE6 activity promoted by the wild-type and mutant STE6/CFTR chimeras. By analysis of protein stability and subcellular localization, we find that the mutant chimera is not ER-retained in yeast. We conclude that the molecular basis for the reduced mating of the STE6/CFTR delta F508 chimera must reflect a reduction in its capacity to transport a-factor, rather than mistrafficking. Thus, STE6/CFTR delta F508 in yeast appears to be a good genetic model to probe certain aspects of protein function, but not to study protein localization" |
| Keywords: | "ATP-Binding Cassette Transporters/*genetics/metabolism Amino Acid Sequence Base Sequence Biological Transport Cloning, Molecular Cystic Fibrosis/*genetics Cystic Fibrosis Transmembrane Conductance Regulator/*genetics/metabolism/physiology DNA Primers Endo;" |
| Notes: | "MedlinePaddon, C Loayza, D Vangelista, L Solari, R Michaelis, S eng F31GM14816/GM/NIGMS NIH HHS/ IP50 DK48977/DK/NIDDK NIH HHS/ Research Support, U.S. Gov't, P.H.S. England 1996/03/01 Mol Microbiol. 1996 Mar; 19(5):1007-17. doi: 10.1046/j.1365-2958.1996.444973.x" |
