Different degradation pathways for heterologous glycoproteins in yeast

Holkeri, Heidi; Makarow, Marja

doi:10.1016/s0014-5793(98)00586-9

Cited by 59 publications

(44 citation statements)

References 38 publications

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“…Our finding that A1PiZ is secreted when CPY-to-vacuole targeting is blocked by deletion of VPS30, VPS38, or VPS10 ( Figure 5B) is consistent with their data and indicates that upon arrival at the TGN, A1PiZ is selected for transport to the vacuole. The existence of a post-ER protein quality control mechanism that is substrate specific is supported further by several reports (Hong et al, 1996;Holkeri and Makarow, 1998;Coughlan et al, 2004). The secretion of A1PiZ in the vps10⌬ strain suggests that Vps10p may be the cargo receptor that binds and transports A1PiZ from the TGN to the vacuole.…”

Section: Discussionmentioning

confidence: 54%

“…The data presented above indicate a requirement for both VPS30 and VPS38 during A1PiZ degradation, and Vps30p and Vps38p are necessary for the recycling of Vps10p, a sorting receptor that plays a role in trafficking CPY (Marcusson et al, 1994;Seaman et al, 1997Seaman et al, , 1998Burda et al, 2002), proteinase A, aminopeptidase Y (Jorgensen et al, 1999, and some misfolded proteins from the Golgi to the vacuole (Hong et al, 1996;Holkeri and Makarow, 1998). We therefore asked whether VPS10 was also required for A1PiZ The yeast were transformed with the 2 pJC104 vector encoding the lacZ gene behind four repeats of the unfolded protein response element in order to measure the UPR.…”

Section: A1piz Is Secreted In Strains Deleted For Vps30 Vps38 and Vmentioning

confidence: 98%

“…Some aberrant soluble proteins in the secretory pathway may escape the ER quality control machinery and are degraded instead in the vacuole (Hong et al, 1996;Holkeri and Makarow, 1998;Jorgensen et al, 1999;Coughlan et al, 2004; reviewed in Arvan et al, 2002). Furthermore, Spear and Ng (2003) reported that the ERAD pathway can be saturated by CPY* overexpression and that excess CPY* is degraded in the vacuole after transiting through the Golgi.…”

Section: Introductionmentioning

confidence: 99%

“…For example, the analysis of topologically distinct ERAD substrates indicates that molecular chaperones in the cytoplasm and in the ER lumen distinguish membrane and soluble substrates, respectively (Huyer et al, 2004), and which chaperones target proteins for degradation is dependent on the site of the misfolded domain (Taxis et al, 2003;Vashist and Ng, 2004; reviewed in Ahner and Brodsky, 2004). Furthermore, the proposal that ERAD substrates are retained in the ER was challenged with the elucidation of the sec-dependent ERAD pathway, in which a soluble ERAD substrate, a misfolded form of carboxypeptidase Y (CPY*), was shown to transit between the ER and Golgi before retrotranslocation and degradation (Caldwell et al, 2001;Vashist et al, 2001;Taxis et al, 2002).Some aberrant soluble proteins in the secretory pathway may escape the ER quality control machinery and are degraded instead in the vacuole (Hong et al, 1996;Holkeri and Makarow, 1998;Jorgensen et al, 1999;Coughlan et al, 2004; reviewed in Arvan et al, 2002). Furthermore, Spear and Ng (2003) reported that the ERAD pathway can be saturated by CPY* overexpression and that excess CPY* is degraded in the vacuole after transiting through the Golgi.…”

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confidence: 99%

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Characterization of anERADGene asVPS30/ATG6Reveals Two Alternative and Functionally Distinct Protein Quality Control Pathways: One for Soluble Z Variant of Human α-1 Proteinase Inhibitor (A1PiZ) and Another for Aggregates of A1PiZ

Kruse

Brodsky

McCracken

2006

MBoC

188

185

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The Z variant of human ␣-1 proteinase inhibitor (A1PiZ) is a substrate for endoplasmic reticulum-associated protein degradation (ERAD). To identify genes required for the degradation of this protein, A1PiZ degradation-deficient (add) yeast mutants were isolated. The defect in one of these mutants, add3, was complemented by VPS30/ATG6, a gene that encodes a component of two phosphatidylinositol 3-kinase (PtdIns 3-kinase) complexes: complex I is required for autophagy, whereas complex II is required for the carboxypeptidase Y (CPY)-to-vacuole pathway. We found that upon overexpression of A1PiZ, both PtdIns 3-kinase complexes were required for delivery of the excess A1PiZ to the vacuole. When the CPY-to-vacuole pathway was compromised, A1PiZ was secreted; however, disruption of autophagy led to an increase in aggregated A1PiZ rather than secretion. These results suggest that excess soluble A1PiZ transits the secretion pathway to the trans-Golgi network and is selectively targeted to the vacuole via the CPY-to-vacuole sorting pathway, but excess A1PiZ that forms aggregates in the endoplasmic reticulum is targeted to the vacuole via autophagy. These findings illustrate the complex nature of protein quality control in the secretion pathway and reveal multiple sites that recognize and sort both soluble and aggregated forms of aberrant or misfolded proteins. INTRODUCTIONCell function and survival depend on protein quality control to identify and remove aberrant proteins. Although two cellular sites of proteolysis are known, the lysosome/vacuole and cytoplasmic 26S proteasome, the recognition of aberrant proteins and mechanisms for delivery to these sites are still being defined. Endoplasmic reticulum-associated degradation (ERAD) is a protein quality control process in which aberrant or misassembled proteins in the secretory pathway are identified and removed (reviewed in Hampton, 2002;Tsai et al., 2002;Kostova and Wolf, 2003;McCracken and Brodsky, 2003). After entering the endoplasmic reticulum (ER), a nascent protein that fails to fold or assemble properly can be "recognized" by the ER quality control machinery, retained within the ER, and then retrotranslocated to the cytoplasm where it is degraded by the proteasome.The recognition of ERAD substrates must exhibit flexibility to distinguish slowly folding proteins from aberrant proteins. Molecular chaperones play a critical role in this selection process; for example, the ER heat-shock protein (Hsp70), BiP, is vital for the selection of soluble substrates and is believed to hold the substrates in an unfolded state competent for retrotranslocation (Nishikawa et al., 2001;Kabani et al., 2003).The complexity of the ERAD pathway has emerged with the identification of new ERAD substrates and the components required for their selection and degradation in yeast. For example, the analysis of topologically distinct ERAD substrates indicates that molecular chaperones in the cytoplasm and in the ER lumen distinguish membrane and soluble substrates, respectively (Huyer et al., 20...

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Section: Discussionmentioning

confidence: 54%

Section: A1piz Is Secreted In Strains Deleted For Vps30 Vps38 and Vmentioning

confidence: 98%

Section: Introductionmentioning

confidence: 99%

mentioning

confidence: 99%

See 2 more Smart Citations

Characterization of anERADGene asVPS30/ATG6Reveals Two Alternative and Functionally Distinct Protein Quality Control Pathways: One for Soluble Z Variant of Human α-1 Proteinase Inhibitor (A1PiZ) and Another for Aggregates of A1PiZ

Kruse

Brodsky

McCracken

2006

MBoC

188

185

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“…Budding yeasts contain a vacuolar sorting receptor called Vps10 that recognizes the carboxypeptidase Y (CPY) precursor as well as certain misfolded proteins [15][16][17][18][19][20]. When msGFP was targeted to the secretory pathway in S. cerevisiae, some of the msGFP molecules reached the vacuole in a Vps10-dependent manner, confirming a report that the quality control function of Vps10 extends to folded GFP [21].…”

Section: Introductionmentioning

confidence: 59%

Secretion of a foreign protein from budding yeasts is enhanced by cotranslational translocation and by suppression of vacuolar targeting

Fitzgerald

Glick

2014

Microb Cell Fact

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Background: Budding yeasts are often used to secrete foreign proteins, but the efficiency is variable. To identify roadblocks in the yeast secretory pathway, we used a monomeric superfolder GFP (msGFP) as a visual tracer in Saccharomyces cerevisiae and Pichia pastoris. Results: One roadblock for msGFP secretion is translocation into the ER. Foreign proteins are typically fused to the bipartite α-factor secretion signal, which consists of the signal sequence followed by the pro region. The α-factor signal sequence directs posttranslational translocation. For msGFP, posttranslational translocation is inefficient with the α-factor signal sequence alone but is stimulated by the pro region. This requirement for the pro region can be bypassed by using the Ost1 signal sequence, which has been shown to direct cotranslational translocation. A hybrid secretion signal consisting of the Ost1 signal sequence followed by the α-factor pro region drives efficient translocation followed by rapid ER export. A second roadblock for msGFP secretion in S. cerevisiae occurs during exit from the Golgi, when some of the msGFP molecules are diverted to the vacuole. Deletion of the sorting receptor Vps10 prevents vacuolar targeting of msGFP at the expense of missorting vacuolar hydrolases such as carboxypeptidase Y (CPY) to the culture medium. However, a truncation of Vps10 blocks vacuolar targeting of msGFP while permitting CPY to be sorted normally. Conclusions: With budding yeasts, if the secretion or processing of a foreign protein is poor, we recommend two options. First, use the Ost1 signal sequence to achieve efficient entry into the secretory pathway while avoiding the processing issues associated with the α-factor pro region. Second, truncate Vps10 to suppress diversion to the vacuole. These insights obtained with msGFP highlight the value of applying cell biological methods to study yeast secretion.

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Distinct classes of misfolded proteins differentially affect the growth of yeast compromised for proteasome function

et al. 2021

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Maintenance of the proteome (proteostasis) is essential for cellular homeostasis and prevents cytotoxic stress responses that arise from protein misfolding. However, little is known about how different types of misfolded proteins impact homeostasis, especially when protein degradation pathways are compromised. We examined the effects of misfolded protein expression on yeast growth by characterizing a suite of substrates possessing the same aggregation‐prone domain but engaging different quality control pathways. We discovered that treatment with a proteasome inhibitor was more toxic in yeast expressing misfolded membrane proteins, and this growth defect was mirrored in yeast lacking a proteasome‐specific transcription factor, Rpn4p. These results highlight weaknesses in the proteostasis network’s ability to handle the stress arising from an accumulation of misfolded membrane proteins.

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Different degradation pathways for heterologous glycoproteins in yeast

Cited by 59 publications

References 38 publications

Characterization of anERADGene asVPS30/ATG6Reveals Two Alternative and Functionally Distinct Protein Quality Control Pathways: One for Soluble Z Variant of Human α-1 Proteinase Inhibitor (A1PiZ) and Another for Aggregates of A1PiZ

Characterization of anERADGene asVPS30/ATG6Reveals Two Alternative and Functionally Distinct Protein Quality Control Pathways: One for Soluble Z Variant of Human α-1 Proteinase Inhibitor (A1PiZ) and Another for Aggregates of A1PiZ

Secretion of a foreign protein from budding yeasts is enhanced by cotranslational translocation and by suppression of vacuolar targeting

Distinct classes of misfolded proteins differentially affect the growth of yeast compromised for proteasome function

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