A novel function of VCP (valosin-containing protein; p97) in the control of N-glycosylation of proteins in the endoplasmic reticulum

Lass, Agnieszka; McConnell, Elizabeth J.; Nowis, Dominika; Mechref, Yehia; Kang, Pilsoo; Novotný, Miloš V.; Wójcik, Cezary

doi:10.1016/j.abb.2007.04.010

Cited by 15 publications

(6 citation statements)

References 57 publications

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“…Similarly, S2′ derived from QQ p97 over-expressing P1 displayed reduced levels of deglycosylated TCRα when compared to those from untransfected and WT p97 controls (Figure 3D, top panel, compare lane 9 to 8 and 7). Consistent with previous reports, these findings not only demonstrate that QQ p97 over-expression can functionally inactivate retro-translocation, but also indicate an important role of p97 activity in the formation of deglycosylated TCRα in cells [32]–[34]. Surprisingly, when mock- and p97-depleted CE were incubated with an untransfected P1, the levels of deglycosylated TCRα in the resulting S2′ fractions were unaffected (Figure 3E, top panel, compare lane 2 to 1).…”

Section: Resultssupporting

confidence: 91%

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Establishment of an In Vitro Transport Assay That Reveals Mechanistic Differences in Cytosolic Events Controlling Cholera Toxin and T-Cell Receptor α Retro-Translocation

Moore

Tsai

2013

PLoS ONE

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Following retrograde trafficking to the endoplasmic reticulum (ER), cholera toxin A1 (CTA1) subunit hijacks ER-associated degradation (ERAD) machinery and retro-translocates into the cytosol to induce toxicity. We previously established a cell-based in vivo assay to identify ER components that regulate this process. However, elucidating cytosolic events that govern CTA1 retro-translocation using this assay is difficult as manipulating cytosolic factors often perturbs toxin retrograde transport to the ER. To circumvent this problem, we developed an in vitro assay in semi-permeabilized cells that directly monitors CTA1 release from the ER into the cytosol. We demonstrate CTA1 is released into the cytosol as a folded molecule in a p97- and proteasome-independent manner. Release nonetheless involves a GTP-dependent reaction. Upon extending this assay to the canonical ERAD substrate T-cell receptor α (TCRα), we found the receptor is unfolded when released into the cytosol and degraded by membrane-associated proteasome. In this reaction, p97 initially extracts TCRα from the ER membrane, followed by TCRα discharge into the cytosol that requires additional energy-dependent cytosolic activities. Our results reveal mechanistic insights into cytosolic events controlling CTA1 and TCRα retro-translocation, and provide a reliable tool to further probe this process.

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Section: Resultssupporting

confidence: 91%

“…In agreement with previous reports [32]–[34], p97 catalyzes an important step in TCRα retro-translocation and degradation. Specifically, expression of an ATPase-defective p97 mutant decreased appearance of deglycosylated TCRα species in both membrane as well as in vivo and in vitro cytosolic fractions.…”

Section: Discussionsupporting

confidence: 93%

Establishment of an In Vitro Transport Assay That Reveals Mechanistic Differences in Cytosolic Events Controlling Cholera Toxin and T-Cell Receptor α Retro-Translocation

Moore

Tsai

2013

PLoS ONE

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Section: Role Of Vcp In Er and Post-er Compartmentsmentioning

confidence: 98%

“…Complementation of the HTM1 (EDEM) or Cdc48 (VCP) deficiency in yeast cells by the mammalian orthologue EDEM or VCP underlines the necessity of these proteins in CFTR degradation and highlights the similarity of quality control and ERAD in yeast and mammals [45]. A novel function of VCP in the control of N‐glycosylation of proteins in the ER was recently demonstrated [46]. Mass spectrometric analysis of cellular N‐linked glycans revealed that depletion of VCP decreases the level of high‐mannose glycoproteins, increases the levels of truncated low‐mannose glycoproteins and induces changes in the abundance of complex glycans assembled in post‐ER compartments.…”

Section: Role Of Vcp In Er and Post‐er Compartmentsmentioning

confidence: 99%

AAA ATPase p97/VCP: cellular functions, disease and therapeutic potential

Vij

2008

J Cellular Molecular Medi

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p97/VCP, a member of the AAA-ATPase super family, has been associated with a wide variety of essential cellular protein pathways com prising: (i) nuclear envelope reconstruction, (ii) cell cycle, (iii) Golgi reassembly, (iv) suppression of apoptosis and (v) DNA-damage response [1-6]. In addition, vasolin-containing protein (VCP) dislodges the ubiquitinated proteins from the endoplasmic reticulum (ER) and chaperones them to the cytosol for proteasomal degradation by endoplasmic reticulum-associated degradation (ERAD) [7]. The interactions of VCP in the endoplasmic reticulum-associated degradation (ERAD) pathway determine the substrate selection for proteasomal degradation. Moreover, the interaction with VCP is also required for the ubiquitination of substrate. VCP is phosphorylated by the master cellular kinase, Akt as a mechanism to regulate ERAD [8]. These multiple interactions in protein degradation pathways points to central role of VCP in misfolded protein degradation. VCP has a poly-glutamine and ubiquitin-binding capacity and is involved in proteasomal degradation, cytosolic aggregation and processing of polyQ and polyUb aggregates in neurodegenerative and other misfolded protein diseases [9, 10]. Mutations in VCP gene are also linked to a protein deposition disorder, IBMFD [11]. We propose VCP as a therapeutic target for diseases caused by cytosolic protein aggregation or degradation of misfolded protein. We predict that selective interference of VCP interaction(s) with aberrant protein or its ERAD function will be an effective therapeutic site to rescue functional misfolded protein in diseases like cystic fibrosis and alpha-1-trypsin deficiency. The control of VCP expression is also proposed to be a potential therapeutic target in ex-polyQ-induced neurodegenerative diseases [12]. The further functional characterization of VCP and associated proteins in these diseases will help in designing of selective therapeutics.

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“…It has been shown that this deglycosylation enzyme is involved in ERAD and cleaves N-glycans from misfolded glycoproteins during their proteasomal degradation [5][6][7][8]. In mammalian cells, some ERAD substrates are presumed to be deglycosylated by the PNGase during the degradation process [7,9,10]. In budding yeast Saccharomyces cerevisiae, a ricin toxin A-chain non-toxic mutant (RTAΔ) and its transmembrane protein derivative, RTL (RTAΔ-transmembrane-Leu2), have been identified as Png1-dependent ERAD substrates [6][7][8]11].…”

Section: Introductionmentioning

confidence: 99%

Cytoplasmic peptide:N-glycanase cleaves N-glycans on a carboxypeptidase Y mutant during ERAD in Saccharomyces cerevisiae

Hosomi

Suzuki

2015

Biochimica et Biophysica Acta (BBA) - General Subjects

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A novel function of VCP (valosin-containing protein; p97) in the control of N-glycosylation of proteins in the endoplasmic reticulum

Cited by 15 publications

References 57 publications

Establishment of an In Vitro Transport Assay That Reveals Mechanistic Differences in Cytosolic Events Controlling Cholera Toxin and T-Cell Receptor α Retro-Translocation

Establishment of an In Vitro Transport Assay That Reveals Mechanistic Differences in Cytosolic Events Controlling Cholera Toxin and T-Cell Receptor α Retro-Translocation

AAA ATPase p97/VCP: cellular functions, disease and therapeutic potential

Cytoplasmic peptide:N-glycanase cleaves N-glycans on a carboxypeptidase Y mutant during ERAD in Saccharomyces cerevisiae

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