Danièle Urban-Grimal

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Yeast uracil permease follows the secretory pathway to the plasma membrane and is phosphorylated on serine residues in a post-Golgi compartment. The protein was found to be rather stable in growing cells, but its turnover rate (half-life of about 7 h) was much faster than that of most yeast proteins. Several adverse conditions triggered the rapid(More)
Endocytosis is involved in a wide variety of cellular processes, and the internalization step of endocytosis has been extensively studied in both lower and higher eukaryotic cells. Studies in mammalian cells have described several endocytic pathways, with the main emphasis on clathrin-dependent endocytosis. Genetic studies in yeast have underlined the(More)
Uptake of uracil by the yeast Saccharomyces cerevisiae is mediated by a specific permease encoded by the FUR4 gene. Uracil permease located at the cell surface is subject to two covalent modifications: phosphorylation and ubiquitination. The ubiquitination step is necessary prior to permease endocytosis and subsequent vacuolar degradation. Here, we(More)
Uracil uptake by Saccharomyces cerevisiae is mediated by the FUR4-encoded uracil permease. The modification of uracil permease by phosphorylation at the plasma membrane is a key mechanism for regulating endocytosis of this protein. This modification in turn facilitates its ubiquitination and internalization. Following endocytosis, the permease is targeted(More)
The ubiquitin ligase (E3) Rsp5p is the only member of the Nedd (neural-precursor-cell-expressed, developmentally down-regulated) 4 family of E3s present in yeast. Rsp5p has several proteasome-independent functions in membrane protein trafficking, including a role in the ubiquitination of most plasma membrane proteins, leading to their endocytosis. Rsp5p is(More)
Nine new hem12 haploid mutants of baker's yeast (Saccharomyces cerevisiae), totally or partially deficient in uroporphyrinogen decarboxylase activity, were subjected to both genetic and biochemical analysis. The mutations sites studied are situated far apart within the HEM12 gene located on chromosome IV. Uroporphyrinogen decarboxylase activity in the(More)
Rsp5p is an ubiquitin (Ub)-protein ligase of the Nedd4 family that carries WW domains involved in interaction with PPXY-containing proteins. It plays a key role at several stages of intracellular trafficking, such as Ub-mediated internalization of endocytic cargoes and Ub-mediated sorting of membrane proteins to internal vesicles of multivesicular bodies(More)
The modification of yeast uracil permease by phosphorylation at the plasma membrane is a key mechanism for regulating transporter endocytosis. Uracil permease is phosphorylated at several serine residues within a well characterized PEST sequence. The phosphorylation of these residues facilitates the ubiquitination and internalization of the permease.(More)
Precursor forms of vacuolar proteins with transmembrane domains, such as the carboxypeptidase S Cps1p and the polyphosphatase Phm5p, are selectively sorted in endosomal compartments to vesicles that invaginate, budding into the lumen of the late endosomes, resulting in the formation of multivesicular bodies (MVBs). These proteins are then delivered to the(More)
In a multiple deletion mutant hxtlAhxt2Ahxt3A hxt4Asn]'3A of Saccharomyces cerevisiae growing on 2 % glucose, high-affinity glucose-uptake (low Kin) was exhibited throughout growth on glucose in contrast to the wild-type, which exhibited the usual low-affinity to high-affinity transition as the glucose in the medium was consumed. Elevated levels of(More)