Molecular Cloning of a Novel Ubiquitin-like Protein, UBIN, That Binds to ER Targeting Signal Sequences

2001 ◽  
Vol 280 (2) ◽  
pp. 535-540 ◽  
Author(s):  
Miho Matsuda ◽  
Takaki Koide ◽  
Tetuya Yorihuzi ◽  
Nobuko Hosokawa ◽  
Kazuhiro Nagata
Keyword(s):  
Molecular Cloning ◽  
Signal Sequences ◽  
Er Targeting ◽  
Targeting Signal

scholarly journals Take Me Home, Protein Roads: Structural Insights into Signal Peptide Interactions during ER Translocation

2021 ◽  
Vol 22 (21) ◽  
pp. 11871
Author(s):  
A. Manuel Liaci ◽  
Friedrich Förster
Keyword(s):  
Structural Biology ◽  
Signal Peptide ◽  
Target Location ◽  
Signal Recognition Particle ◽  
Signal Peptidase ◽  
Signal Recognition ◽  
Signal Sequences ◽  
Peptide Interactions ◽  
Er Targeting ◽  
Structural Insights

Cleavable endoplasmic reticulum (ER) signal peptides (SPs) and other non-cleavable signal sequences target roughly a quarter of the human proteome to the ER. These short peptides, mostly located at the N-termini of proteins, are highly diverse. For most proteins targeted to the ER, it is the interactions between the signal sequences and the various ER targeting and translocation machineries such as the signal recognition particle (SRP), the protein-conducting channel Sec61, and the signal peptidase complex (SPC) that determine the proteins’ target location and provide translocation fidelity. In this review, we follow the signal peptide into the ER and discuss the recent insights that structural biology has provided on the governing principles of those interactions.

scholarly journals Measuring Endoplasmic Reticulum Signal Sequences Translocation Efficiency Using the Xbp1 Arrest Peptide

2018 ◽  
Author(s):  
Theresa Kriegler ◽  
Anastasia Magoulopoulou ◽  
Rocio Amate Marchal ◽  
Tara Hessa
Keyword(s):  
Signal Sequence ◽  
Dominant Role ◽  
Complex Signal ◽  
Secretory Proteins ◽  
Signal Sequences ◽  
Functional Efficiency ◽  
Nascent Chain ◽  
Er Targeting ◽  
Translational Arrest ◽  
Two Phases

SummarySecretory proteins translocate across the mammalian ER membrane co-translationally via the ribosome-sec61 translocation channel complex. Signal sequences within the polypeptide, which guide this event, are diverse in their hydrophobicity, charge, length, and amino acid composition. Despite the known sequence diversity in the ER-targeting signals, it is generally assumed that they have a dominant role in determining co-translational targeting and translocation initiation process. We have analyzed co-translational events experienced by secretory proteins carrying efficient, versus inefficient (poorly hydrophobic) signal sequences, using an assay based on Xbp1 peptide-mediated translational arrest. With this method we were able to measure the functional efficiency of ER signal sequences. We show that an efficient signal sequence experiences a two-phases event in which the nascent chain is pulled from the ribosome during its translocation, thus resuming translation and yielding full-length products. Conversely, the inefficient signal sequence experiences a single weaker pulling event, suggesting inadequate engagement by the translocation machinery of these marginally hydrophobic signal sequences.

scholarly journals Signal Peptide of HIV-1 Envelope Modulates Glycosylation Impacting Exposure of V1V2 Epitopes

2020 ◽  
Author(s):  
Chitra Upadhyay ◽  
Roya Feyznezhad ◽  
Liwei Cao ◽  
Kun-Wei Chan ◽  
Kevin Liu ◽  
...  
Keyword(s):  
Signal Peptide ◽  
Neutralizing Antibodies ◽  
Single Point ◽  
Virus Neutralization ◽  
Site Specific ◽  
Er Targeting ◽  
Targeting Signal ◽  
The Impact ◽  
Hiv 1 ◽  
V1v2 Region

AbstractHIV-1 envelope (Env) is a trimer of gp120-gp41 heterodimers, synthesized from a precursor gp160 that contains an ER-targeting signal peptide (SP) at its amino-terminus. Each trimer is swathed by ∼90 N-linked glycans, comprising complex-type and oligomannose-type glycans, which play an important role in determining virus sensitivity to neutralizing antibodies. We previously examined the effects of single point SP mutations on Env properties and functions. Here, we aimed to understand the impact of the SP diversity on glycosylation of virus-derived Env and virus neutralization by swapping SPs. Analyses of site-specific glycans revealed that SP swapping altered Env glycan content and occupancy on multiple N-linked glycosites, including the conserved N156 and N160 glycans in the V1V2 region at the Env trimer apex. Virus neutralization was also affected, especially by antibodies against the V2i, V2p and V2q epitopes. Likewise, SP swaps affected the recognition of soluble and cell-associated Env by antibodies targeting distinct V1V2 configurations. These data highlight the contribution of SP sequence diversity in shaping the Env glycan content and its impact on the configuration and accessibility of V1V2 epitopes on Env.Author SummaryHIV-1 Env glycoprotein is produced by a precursor gp160 that has a signal peptide at its N-terminus. The SP is highly diverse among the HIV-1 isolates and no two SP are same. This study presents site-specific analyses of N-linked glycosylation on HIV-1 envelope glycoproteins from infectious viruses produced with different envelope signal peptides. We show that signal peptide swapping alters the envelope glycan shield, including the conserved N156 and N160 located in the V1V2 region on the trimer apex, to impact Env recognition and virus neutralization by antibodies, particularly those targeting the the V1V2 region. The data offer crucial insights into the role of signal peptide in the interplay between HIV-1 and antibodies and its potential utility to control Env glycosylation in the development of Env-based HIV-1 vaccine.

scholarly journals Signal peptide of HIV-1 envelope modulates glycosylation impacting exposure of V1V2 and other epitopes

2020 ◽  
Vol 16 (12) ◽  
pp. e1009185
Author(s):  
Chitra Upadhyay ◽  
Roya Feyznezhad ◽  
Liwei Cao ◽  
Kun-Wei Chan ◽  
Kevin Liu ◽  
...  
Keyword(s):  
Signal Peptide ◽  
Neutralizing Antibodies ◽  
Single Point ◽  
Virus Neutralization ◽  
Complex Type ◽  
Er Targeting ◽  
Targeting Signal ◽  
The Impact ◽  
Hiv 1 ◽  
V1v2 Region

HIV-1 envelope (Env) is a trimer of gp120-gp41 heterodimers, synthesized from a precursor gp160 that contains an ER-targeting signal peptide (SP) at its amino-terminus. Each trimer is swathed by ~90 N-linked glycans, comprising complex-type and oligomannose-type glycans, which play an important role in determining virus sensitivity to neutralizing antibodies. We previously examined the effects of single point SP mutations on Env properties and functions. Here, we aimed to understand the impact of the SP diversity on glycosylation of virus-derived Env and virus neutralization by swapping SPs. Analyses of site-specific glycans revealed that SP swapping altered Env glycan content and occupancy on multiple N-linked glycosites, including conserved N156 and N160 glycans in the V1V2 region at the Env trimer apex and N88 at the trimer base. Virus neutralization was also affected, especially by antibodies against V1V2, V3, and gp41. Likewise, SP swaps affected the recognition of soluble and cell-associated Env by antibodies targeting distinct V1V2 configurations, V3 crown, and gp41 epitopes. These data highlight the contribution of SP sequence diversity in shaping the Env glycan content and its impact on the configuration and accessibility of V1V2 and other Env epitopes.

Dissection of the molecular mechanisms of protein targeting to the peroxisome using immunofluorescence and immunocryoelectron microscopies

1990 ◽  
Vol 48 (3) ◽  
pp. 44-45
Author(s):  
G-A. Keller ◽  
S. J. Gould ◽  
S. Subramani ◽  
S. Krisans
Keyword(s):  
Mammalian Cells ◽  
Molecular Mechanisms ◽  
Protein Targeting ◽  
Firefly Luciferase ◽  
Peroxisomal Enzyme ◽  
Transfected Cells ◽  
Peroxisomal Targeting ◽  
Targeting Signal ◽  
Series Of Experiments ◽  
Peroxisomal Targeting Signal

Subcellular compartments within eukaryotic cells must each be supplied with unique sets of proteins that must be directed to, and translocated across one or more membranes of the target organelles. This transport is mediated by cis- acting targeting signals present within the imported proteins. The following is a chronological account of a series of experiments designed and carried out in an effort to understand how proteins are targeted to the peroxisomal compartment.-We demonstrated by immunocryoelectron microscopy that the enzyme luciferase is a peroxisomal enzyme in the firefly lantern. -We expressed the cDNA encoding firefly luciferase in mammalian cells and demonstrated by immunofluorescence that the enzyme was transported into the peroxisomes of the transfected cells. -Using deletions, linker insertions, and gene fusion to identify regions of luciferase involved in its transport to the peroxisomes, we demonstrated that luciferase contains a peroxisomal targeting signal (PTS) within its COOH-terminal twelve amino acid.

Molecular cloning and characterization of vernalization-related (ver) genes in winter wheat

1994 ◽  
Vol 92 (3) ◽  
pp. 511-515 ◽  
Author(s):  
Kang Chong ◽  
Li-Ping Wang ◽  
Ke-Hui Tan ◽  
Hua-Liang Huang ◽  
Hou-Guo Liang
Keyword(s):  
Winter Wheat ◽  
Molecular Cloning
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