Erv41p and Erv46p

Otte, Stefan; Belden, William J.; Heidtman, Matthew; Liu, Jay; Jensen, Ole Mejlhede; Barlowe, Charles

doi:10.1083/jcb.152.3.503

Cited by 129 publications

(88 citation statements)

References 65 publications

(92 reference statements)

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“…Antibodies against Erv25p (30), Och1p (31), and Sec22p (14) have been published. Western blots were developed using the ECL method (Amersham Biosciences).…”

Section: Methodsmentioning

confidence: 99%

“…Subcellular Fractionation-Membrane organelles prepared from cell lysates were resolved on 18 -60% sucrose density gradients (32) with modifications (31,33). Gradient fractions were collected and diluted with SDS-PAGE sample buffer and immunoblotted for Sec61p (ER marker), Och1p (Golgi marker), and Sec22p.…”

Section: Methodsmentioning

confidence: 99%

“…To examine the localization of these mutant proteins, we employed a subcellular fractionation procedure to resolve ER and Golgi compartments on sucrose gradients (31,33). The resolution of ER and Golgi compartments with this method was confirmed by monitoring the Golgi-localized marker Och1p, which peaked in fractions that were separated from the ER marker, Sec61p.…”

Section: The N-terminal Domain Of Yeast Sec22p Is Required Formentioning

confidence: 99%

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Sec22p Export from the Endoplasmic Reticulum Is Independent of SNARE Pairing

Liu

Flanagan

Barlowe

2004

Journal of Biological Chemistry

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Molecularly distinct sets of SNARE proteins localize to specific intracellular compartments and catalyze membrane fusion events. Although their central role in membrane fusion is appreciated, little is known about the mechanisms by which individual SNARE proteins are targeted to specific organelles. Here we investigated functional domains in Sec22p that direct this SNARE protein to the endoplasmic reticulum (ER), to Golgi membranes, and into SNARE complexes with Bet1p, Bos1p, and Sed5p. A series of Sec22p deletion mutants were monitored in COPII budding assays, subcellular fractionation gradients, and SNARE complex immunoprecipitations. We found that the N-terminal "profilinlike" domain of Sec22p was required but not sufficient for COPII-dependent export of Sec22p from the ER. Interestingly, versions of Sec22p that lacked the N-terminal domain were assembled into ER/Golgi SNARE complexes. Analyses of Sec22p SNARE domain mutants revealed a second signal within the SNARE motif (between layers ؊4 and ؊1) that was required for efficient ER export. Other SNARE domain mutants that contained this signal were efficiently packaged into COPII vesicles but failed to assemble into SNARE complexes. Together these results indicated that SNARE complex formation is neither required nor sufficient for Sec22p packaging into COPII transport vesicles and subsequent targeting to the Golgi complex. We propose that the COPII budding machinery has a preference for unassembled ER/Golgi SNARE proteins.In eukaryotic cells, most intracellular membrane fusion processes are mediated by a related family of small proteins, called SNARE 1 (soluble NSF attachment protein receptors) proteins (1, 2). SNAREs share a conserved heptad repeat coiled coil sequence, called the SNARE domain, that is typically adjacent to a C-terminal-membrane bound region (3). Specific sets of SNARE domains assemble into parallel four-helix bundles forming the stable core of a SNARE protein complex (4 -6). Current membrane fusion models theorize that cognate sets of SNARE proteins provided from opposing membranes assemble into "trans" SNARE complexes and drive membrane bilayers together during fusion (2, 7).The assembly of cognate SNAREs has also been proposed to define the compartmental specificity of membrane fusion based on experiments showing that only specific combinations of SNARE proteins catalyze in vitro fusion when reconstituted into synthetic proteoliposomes (8 -10). However, this proposal remains debated given the promiscuity of SNARE interactions in vitro (11-13), functional redundancy in vivo (14, 15), and requirements for individual SNARE proteins in multiple intracellular membrane fusion steps (16). These and other observations suggest that additional spatial and temporal determinants in SNARE proteins contribute to the specificity of the membrane fusion (2). The N-terminal domains of SNARE proteins display significant diversity and appear to govern SNARE protein activity and distribution. For example, the N-terminal domain of the syntaxin-like SNARE prot...

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“…Antibodies against Erv25p (30), Och1p (31), and Sec22p (14) have been published. Western blots were developed using the ECL method (Amersham Biosciences).…”

Section: Methodsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

Section: The N-terminal Domain Of Yeast Sec22p Is Required Formentioning

confidence: 99%

See 1 more Smart Citation

Sec22p Export from the Endoplasmic Reticulum Is Independent of SNARE Pairing

Liu

Flanagan

Barlowe

2004

Journal of Biological Chemistry

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“…Surf-4 (surfeit locus 4) gene belongs to a cluster of highly conserved housekeeping genes (67), and the corresponding protein is the human ortholog of Erv29p of yeast. Erv29p is also enriched in COPII vesicles and operates as a transport receptor for specific cargo in yeast (66,68). Surf-4 encodes a 30-kDa protein localized in the early secretory pathway, but its function is unknown (69).…”

Section: Purification Of Ergic Membranes From Bfa-treated Cells-mentioning

confidence: 99%

“…hYif1p is the human ortholog of yeast Yif1p a protein enriched in COPII vesicles (66). Surf-4 (surfeit locus 4) gene belongs to a cluster of highly conserved housekeeping genes (67), and the corresponding protein is the human ortholog of Erv29p of yeast.…”

Section: Purification Of Ergic Membranes From Bfa-treated Cells-mentioning

confidence: 99%

Proteomics of Endoplasmic Reticulum-Golgi Intermediate Compartment (ERGIC) Membranes from Brefeldin A-treated HepG2 Cells Identifies ERGIC-32, a New Cycling Protein That Interacts with Human Erv46

Breuza

Halbeisen

Jenö

et al. 2004

Journal of Biological Chemistry

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113

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Cycling proteins play important roles in the organization and function of the early secretory pathway by participating in membrane traffic and selective transport of cargo between the endoplasmic reticulum (ER), the intermediate compartment (ERGIC), and the Golgi. To identify new cycling proteins, we have developed a novel procedure for the purification of ERGIC membranes from HepG2 cells treated with brefeldin A, a drug known to accumulate cycling proteins in the ERGIC. Membranes enriched 110-fold over the homogenate for ERGIC-53 were obtained and analyzed by mass spectrometry. Major proteins corresponded to established and putative cargo receptors and components mediating protein maturation and membrane traffic. Among the uncharacterized proteins, a 32-kDa protein termed ERGIC-32 is a novel cycling membrane protein with sequence homology to Erv41p and Erv46p, two proteins enriched in COPII vesicles of yeast. ERGIC-32 localizes to the ERGIC and partially colocalizes with the human homologs of Erv41p and Erv46p, which mainly localize to the cis-Golgi. ERGIC-32 interacts with human Erv46 (hErv46) as revealed by covalent cross-linking and mistargeting experiments, and silencing of ERGIC-32 by small interfering RNAs increases the turnover of hErv46. We propose that ERGIC-32 functions as a modulator of the hErv41-hErv46 complex by stabilizing hErv46. Our novel approach for the isolation of the ERGIC from BFA-treated cells may ultimately lead to the identification of all proteins rapidly cycling early in the secretory pathway.

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Mutants defective in secretory/vacuolar pathways in the EUROFAN collection of yeast disruptants

Avaro

Belgareh‐Touzé

Sibella-Argüelles

et al. 2002

Yeast

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We have screened the EUROFAN (European Functional Analysis Network) deletion strain collection for yeast mutants defective in secretory/vacuolar pathways and/or associated biochemical modifications. We used systematic Western immunoblotting to analyse the electrophoretic pattern of several markers of the secretory/vacuolar pathways, the soluble a-factor, the periplasmic glycoprotein invertase, the plasma membrane GPIanchored protein Gas1p, and two vacuolar proteins, the soluble carboxypeptidase Y and the membrane-bound alkaline phosphatase, which are targeted to the vacuole by different pathways. We also used colony immunoblotting to monitor the secretion of carboxypeptidase Y into the medium, to identify disruptants impaired in vacuolar targeting. We identified 25 mutants among the 631 deletion strains. Nine of these mutants were disrupted in genes identified in recent years on the basis of their involvement in trafficking (VPS53, VAC7, VAM6, APM3, SYS1), or glycosylation (ALG12, ALG9, OST4, ROT2). Three of these genes were identified on the basis of trafficking defects by ourselves and others within the EUROFAN project (TLG2, RCY1, MON2). The deletion of ERV29, which encodes a COPII vesicle protein, impaired carboxypeptidase Y trafficking from the endoplasmic reticulum to the Golgi apparatus. We also identified eight unknown ORFs, the deletion of which reduced Golgi glycosylation or impaired the Golgi to vacuole trafficking of carboxypeptidase Y. YJR044c, which we identified as a new VPS gene, encodes a protein with numerous homologues of unknown function in sequence databases.

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Erv41p and Erv46p

Cited by 129 publications

References 65 publications

Sec22p Export from the Endoplasmic Reticulum Is Independent of SNARE Pairing

Sec22p Export from the Endoplasmic Reticulum Is Independent of SNARE Pairing

Proteomics of Endoplasmic Reticulum-Golgi Intermediate Compartment (ERGIC) Membranes from Brefeldin A-treated HepG2 Cells Identifies ERGIC-32, a New Cycling Protein That Interacts with Human Erv46

Mutants defective in secretory/vacuolar pathways in the EUROFAN collection of yeast disruptants

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