| Title: | Endocytosis is required for the growth of vacuolar H(+)-ATPase-defective yeast: identification of six new END genes |
| Address: | "Department of Biochemistry, Biozentrum of the University of Basel, Switzerland" |
| ISSN/ISBN: | 0021-9525 (Print) 1540-8140 (Electronic) 0021-9525 (Linking) |
| Abstract: | "Yeast mutants that are defective in acidification of the lysosome-like vacuole are able to grow at pH 5.5, but not at pH 7. Here, we present evidence that endocytosis is required for this low pH-dependent growth and use this observation to develop a screen for mutants defective in endocytosis. By isolating mutants that cannot grow when they lack the 60-kD vacuolar ATPase subunit (encoded by the VAT2 gene), we isolated a number of vat2-synthetic lethal (Vsl-) mutant strains. Seven of the Vsl- mutants are defective in endocytosis. Four of these mutant strains (end8-1, end9-1, end10-1, and end11-1) show altered uptake of the endocytosed ligand, alpha-factor, and three (end12-1, end12-2, and end13-1) are probably defective in transfer of internalized material to the vacuole. Most of the mutations also confer a strong Ts- growth defect. The mutants defective in uptake of alpha-factor sort newly synthesized vacuolar proteins correctly, while those which may be defective in subsequent transport steps secrete at least a fraction of the newly synthesized soluble vacuolar proteins. The mutations that result in a defect in alpha-factor uptake are not allelic to any of the genes previously shown to encode endocytic functions" |
| Keywords: | "Carboxypeptidases/metabolism Cathepsin A Culture Media Endocytosis/*genetics *Genes, Fungal Genes, Lethal Hydrogen-Ion Concentration Isoquinolines/metabolism Mating Factor Mutation Peptides/metabolism Proton-Translocating ATPases/genetics/*metabolism Sacc;" |
| Notes: | "MedlineMunn, A L Riezman, H eng Research Support, Non-U.S. Gov't 1994/10/01 J Cell Biol. 1994 Oct; 127(2):373-86. doi: 10.1083/jcb.127.2.373" |
