Lactacystin, an Inhibitor of the Proteasome, Blocks the Degradation of a Mutant Precursor of Glycosylphosphatidylinositol-Linked Protein in a Pre-Golgi Compartment

Oda, Kimimitsu; Ikehara, Yukio; Ōmura, Satoshi

doi:10.1006/bbrc.1996.0314

Cited by 29 publications

(15 citation statements)

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“…The mechanism leading to the different BiP interaction and cellular routing between PrP 217 and PrP32 is unclear. It might be due to the lack of the GPI anchor and/or the presence of the GPI signal peptide that makes it impossible for PrP32 to enter the secretory pathway (27)(28)(29)(30)(31)(32). Other mechanisms are also possible.…”

Section: Discussionmentioning

confidence: 99%

The Chaperone Protein BiP Binds to a Mutant Prion Protein and Mediates Its Degradation by the Proteasome

Jin

Zanusso

et al. 2000

Journal of Biological Chemistry

156

106

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Familial prion diseases are thought to result from a change in structure of the mutant prion protein (PrP), which takes a pathogenic conformation. We have examined the role of molecular chaperones in the folding of normal and mutant PrP Q217R (PrP 217 ) in transfected neuroblastoma cells. In a previous report we showed that, although most of the PrP 217 forms escape the endoplasmic reticulum quality control system and aggregate in post-Golgi compartments, a significant proportion of PrP 217 retains the C-terminal glycosylphosphatidyl inositol signal peptide (PrP32), and does not exit the endoplasmic reticulum (Singh, N., Zanusso, G., Chen, S. G., Fujioka, H., Richardson, S., Gambetti, P., and Petersen, R. B. (1997) J. Biol. Chem. 272, 28461-28470). We have now studied the folding and turnover of PrP32 to understand the mechanism by which abnormal PrP forms cause cellular toxicity in our cell culture model and in the human brain carrying the GerstmannSträ ussler-Scheinker disease Q217R mutation. In this report, we show that PrP32 remains associated with the chaperone BiP for an abnormally prolonged period of time and is degraded by the proteasomal pathway. This study is the first demonstration that BiP is chaperoning the folding of PrP and plays a role in maintaining the quality control in the PrP maturation pathway. Our data provide new insight into the diverse pathways of mutant PrP metabolism and neurotoxicity.

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Section: Discussionmentioning

confidence: 99%

The Chaperone Protein BiP Binds to a Mutant Prion Protein and Mediates Its Degradation by the Proteasome

Jin

Zanusso

et al. 2000

Journal of Biological Chemistry

156

106

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“…At present, a cysteine protease(s) inhibited by LLM and LLnL has been implicated in the degradation of HMG‐CoA reductase [22], apolipoprotein B [23], and IgM [24], and a serine protease(s) inhibited by dichloroisocoumarin, tosyl‐phenylalanyl‐chloromethyl ketone, and tosyl‐lysyl‐chloromethyl ketone is a candidate for IgM light chain breakdown [25]. Very recently, degradations of ΔF508 mutant of cystic fibroblast transmembrane conductance regulator (CFTR) [26, 27], MHC class I heavy chain in cytomegarovirus‐transfected cells [28]and glycosylphosphatidylinositol (GPI)‐linked protein [29]were found to be inhibited by proteasomal inhibitors. In this study, we observed that inhibitors for proteasome, such as LLL, LLnV and lactacystin, showed potent inhibitory effects on the degradation of antithrombin mutants (Fig.…”

Section: Discussionmentioning

confidence: 99%

Intracellular degradation of secretion defect‐type mutants of antithrombin is inhibited by proteasomal inhibitors

et al. 1997

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To examine the cellular basis for secretion defect-type antithrombin deficiency, we expressed two mutants, P->stop (Pro 429 to stop codon) and AGlu (deletion of Glu 313 ). Pulse-chase experiments using stably transfected BHK cells showed that little ( < 5%) of P -> stop mutant as well as AGlu mutant was secreted and the total amount of radioactivity was significantly reduced, suggesting an intracellular degradation. The degradation was not inhibited by brefeldin A, indicating it occurring in a preGolgi apparatus. However, the degradation was strongly inhibited by proteasomal inhibitors, such as carbobenzoxy-L-leucyl-L-leucyl-L-leucinal (LLL), carbobenzoxy-L-leucyl-L-leucyl-L-norvalinal (LLnV) and lactacystin. By endoglycosidase H digestion and immunofluorescence staining, these mutants were shown to localize in the endoplasmic reticulum (ER). These results suggest that the secretion defect-type mutants of antithrombin are degraded by proteasome through the ER-associated quality control mechanism in the cells.

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“…Recently, a novel streptomyces metabolite, lactacystin, discovered on the basis of its ability to induce neurite outgrowth in the murine neuroblastoma cell line Neuro-2A (Katagiri et al, 1995;Fenteany et al, 1994;Fenteany and Schreiber, 1996), has emerged as a highly speci®c, irreversible inhibitor of 26S proteasome chymotrypsin-like and trypsin-like activity, without a ecting lysosomal and nonlysosomal cysteine proteases, cathepsin or calpain (Fenteany et al, 1995). The inhibitory e ect of lactacystin on ubiquitin/ATP-dependent degradation of several proteins has been demonstrated both in mammalian cells (Blagosklonny et al, 1996;Bies and Wol , 1997;Oda et al, 1996;Mimnaugh et al, 1996;Lee and Goldberg, 1996; Je ers et al, 1997; Whitesell et al, 1997) and in yeast .…”

Section: Introductionmentioning

confidence: 99%

In vivo degradation of N-myc in neuroblastoma cells is mediated by the 26S proteasome

et al. 1998

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Lactacystin, an Inhibitor of the Proteasome, Blocks the Degradation of a Mutant Precursor of Glycosylphosphatidylinositol-Linked Protein in a Pre-Golgi Compartment

Cited by 29 publications

References 0 publications

The Chaperone Protein BiP Binds to a Mutant Prion Protein and Mediates Its Degradation by the Proteasome

The Chaperone Protein BiP Binds to a Mutant Prion Protein and Mediates Its Degradation by the Proteasome

Intracellular degradation of secretion defect‐type mutants of antithrombin is inhibited by proteasomal inhibitors

In vivo degradation of N-myc in neuroblastoma cells is mediated by the 26S proteasome

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