Endocytosis and degradation of the yeast uracil permease under adverse conditions

Volland, Christiane; Urban‐Grimal, Danièle; Géraud, Gérard; Haguenauer‐Tsapis, Rosine

doi:10.1016/s0021-9258(17)36959-4

Cited by 251 publications

(45 citation statements)

References 53 publications

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“…Several different pathways have been identified by which proteins can be targeted to the vacuole for degradation. A number of membrane proteins, including pheromone receptors and permeases, whose abundance in the plasma membrane is regulated, are removed from the plasma membrane and transported to the vacuole for degradation via the endocytic pathway (Davis et al, 1993;Berkower et al, 1994;Schandel and Jenness, 1994;Volland et al, 1994;Hicke and Riezman, 1996). A second path for protein import into the vacuole is autophagocytosis where, in response to nutrient deprivation, portions of the cytosol and organelles are engulfed and degraded by the vacuole (Takeshige et al, 1992).…”

Section: Discussionmentioning

confidence: 99%

A pathway for targeting soluble misfolded proteins to the yeast vacuole.

Hong

Davidson

Kaiser

1996

The Journal of Cell Biology

166

143

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Abstract. We have evaluated the fate of misfolded protein domains in the Saccharomyces cerevisiae secretory pathway by fusing mutant forms of the NH2-terminal domain of h repressor protein to the secreted protein invertase. The hybrid protein carrying the wild-type repressor domain is mostly secreted to the cell surface, whereas hybrid proteins with amino acid substitutions that cause the repressor domain to be thermodynamically unstable are retained intracellularly. Surprisingly, the retained hybrids are found in the vacuole, where the repressor moiety is degraded by vacuolar proteases. The following observations indicate that receptor-mediated recognition of the mutant repressor domain in the Golgi lumen targets these hybrid fusions to the vacuole. UKARYOTIC cells have the ability to discriminate between correctly folded and misfolded proteins within the secretory pathway. Experimentally, secretory proteins can be prevented from achieving their native folded conformations by mutation (Doms et al., 1988;Cheng et al., 1990), expression of single subunits of multisubunit complexes (Lippincott-Schwartz et al., 1988;Wikstrom and Lodish, 1992), or by inhibition of glycosylation or disulfide bond formation (Olden et al., 1979;Braakman et al., 1992). In all of these cases, failure either to fold or to oligomerize properly causes the protein to be retained intracellularly, most often in the ER, and then to be degraded. The capacity of the cell to retain and to degrade unfolded or unassembled secretory proteins constitutes a quality control process that prevents secretion of defective gene products to the cell surface and allows for the salvage of amino acids from nonfunctional proteins (de Silva et al., 1990;McCracken and Brodsky, 1996).To gain access to the mechanisms that underlie quality control of secretory proteins, we have developed a method to examine systematically the fate of unfolded polypeptides in the Saccharomyces cerevisiae secretory pathway. men of the ER as a fusion protein and to compare the fate of a folded, wild-type domain to that of mutant domains that are thermodynamically unstable. We chose as a test protein the 92-amino acid NH2-terminal DNA-binding domain of the phage k repressor. Crystallographic and biochemical analyses have shown that the NH2-terminal domain of h repressor is a compact globular structure without solvent-exposed hydrophobic regions or flexible strands that might be recognized as unfolded substrate (Pabo and Lewis, 1982). Moreover, folding of the repressor domain in the ER lumen should not be impeded by inappropriate disulfide bond formation or carbohydrate addition since the amino acid sequence does not contain cysteine residues or potential sites for N-linked glycosylation. The effect of unfolding of the NH2-terminal domain of k repressor can be tested using mutants that reduce the thermal stability of the protein. For most of our work, we use a Leu 57 to Ala mutation that reduces the hydrophobicity of the core of the folded protein, thereby lowering the temperature of 50% t...

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Section: Discussionmentioning

confidence: 99%

A pathway for targeting soluble misfolded proteins to the yeast vacuole.

Hong

Davidson

Kaiser

1996

The Journal of Cell Biology

166

143

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“…Samples containing Isolated vacuoles were prepared as indicated above. Whole cell lysates were prepared as previously described (Volland et al, 1994). In brief, yeast cells were grown overnight in YPD medium at 30 C in a shaking incubator to mid-log phase before harvesting them by centrifugation (3,000 g for 5 minutes).…”

Section: Western Blot Analysismentioning

confidence: 99%

Rab-Effector-Kinase Interplay Modulates Intralumenal Fragment Formation during Vacuole Fusion

et al. 2018

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Upon vacuolar lysosome (or vacuole) fusion in S. cerevisiae, a portion of membrane is internalized and catabolized. Formation of this intralumenal fragment (ILF) is important for organelle protein and lipid homeostasis and remodeling. But how ILF formation is optimized for membrane turnover is not understood. Here, we show that fewer ILFs form when the interaction between the Rab-GTPase Ypt7 and its effector Vps41 (a subunit of the tethering complex HOPS) is interrupted by a point mutation (Ypt7-D44N). Subsequent phosphorylation of Vps41 by the casein kinase Yck3 prevents stabilization of trans-SNARE complexes needed for lipid bilayer pore formation. Impairing ILF formation prevents clearance of misfolded proteins from vacuole membranes and promotes organelle permeability and cell death. We propose that HOPS coordinates Rab, kinase, and SNARE cycles to modulate ILF size during vacuole fusion, regulating lipid and protein turnover important for quality control and membrane integrity.

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“…Wild-type and rcy1 ⌬ cells were transformed with a construct (p195gF) (2 URA3-Gal-FUR4) to overexpress uracil permease (Volland et al, 1994). These strains were grown in yeast nitrogen base medium plus 4% galactose and the required amino acids to an OD 600 of 0.6.…”

Section: Uracil Permease Assaysmentioning

confidence: 99%

The F-Box Protein Rcy1p Is Involved in Endocytic Membrane Traffic and Recycling Out of an Early Endosome in Saccharomyces cerevisiae

Wiederkehr

Avaro

Prescianotto-Baschong

et al. 2000

The Journal of Cell Biology

157

184

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In Saccharomyces cerevisiae, endocytic material is transported through different membrane-bound compartments before it reaches the vacuole. In a screen for mutants that affect membrane trafficking along the endocytic pathway, we have identified a novel mutant disrupted for the gene YJL204c that we have renamed RCY1 (recycling 1). Deletion of RCY1 leads to an early block in the endocytic pathway before the intersection with the vacuolar protein sorting pathway. Mutation of RCY1 leads to the accumulation of an enlarged compartment that contains the t-SNARE Tlg1p and lies close to areas of cell expansion. In addition, endocytic markers such as Ste2p and the fluorescent dyes, Lucifer yellow and FM4-64, were found in a similar enlarged compartment after their internalization. To determine whether rcy1Δ is defective for recycling, we have developed an assay that measures the recycling of previously internalized FM4-64. This method enables us to follow the recycling pathway in yeast in real time. Using this assay, it could be demonstrated that recycling of membranes is rapid in S. cerevisiae and that a major fraction of internalized FM4-64 is secreted back into the medium within a few minutes. The rcy1Δ mutant is strongly defective in recycling.

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Endocytosis and degradation of the yeast uracil permease under adverse conditions

Cited by 251 publications

References 53 publications

A pathway for targeting soluble misfolded proteins to the yeast vacuole.

A pathway for targeting soluble misfolded proteins to the yeast vacuole.

Rab-Effector-Kinase Interplay Modulates Intralumenal Fragment Formation during Vacuole Fusion

The F-Box Protein Rcy1p Is Involved in Endocytic Membrane Traffic and Recycling Out of an Early Endosome in Saccharomyces cerevisiae

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