Jove
Visualize
Contact Us
JoVE
x logofacebook logolinkedin logoyoutube logo
ABOUT JoVE
OverviewLeadershipBlogJoVE Help Center
AUTHORS
Publishing ProcessEditorial BoardScope & PoliciesPeer ReviewFAQSubmit
LIBRARIANS
TestimonialsSubscriptionsAccessResourcesLibrary Advisory BoardFAQ
RESEARCH
JoVE JournalMethods CollectionsJoVE Encyclopedia of ExperimentsArchive
EDUCATION
JoVE CoreJoVE BusinessJoVE Science EducationJoVE Lab ManualFaculty Resource CenterFaculty Site
Terms & Conditions of Use
Privacy Policy
Policies

Related Concept Videos

Leaky Scanning02:28

Leaky Scanning

5.6K
During most eukaryotic translation processes, the small 40S ribosome subunit scans an mRNA from its 5' end until it encounters the first start AUG codon. The large 60S ribosomal subunit then joins the smaller one to initiate protein synthesis. The location of the translation initiation is largely determined by the nucleotides near the start codon as there may be multiple translation initiation sites present on the mRNA.  Marilyn Kozak discovered that the sequence RCCAUGG (where R...
5.6K
Conjugated Proteins02:50

Conjugated Proteins

27.4K
Simple proteins and protein complexes contain only amino acids. In contrast, many other proteins, called conjugated proteins, covalently bond with non-protein moieties.
Nucleoproteins are protein complexes that contain nucleic acids, categorized as deoxyribonucleoproteins (DNPs) or ribonucleoproteins (RNPs) respectively. The nucleosome is a typical example of a DNP where nuclear DNA is associated with histone proteins. The major antigen for the Covid-19 virus SARS-CoV is an RNP that is critical...
27.4K
Protein Complex Assembly02:41

Protein Complex Assembly

16.6K
Proteins can form homomeric complexes with another unit of the same protein or heteromeric complexes with different types.  Most protein complexes self-assemble spontaneously via ordered pathways, while some proteins need assembly factors that guide their proper assembly. Despite the crowded intracellular environment, proteins usually interact with their correct partners and form functional complexes.
Many viruses self-assemble into a fully functional unit using the infected host cell to...
16.6K
Viral Structure00:56

Viral Structure

73.8K
Viruses are extraordinarily diverse in shape and size, but they all have several structural features in common. All viruses have a core that contains a DNA- or RNA-based genome. The core is surrounded by a protective coat of proteins called the capsid. The capsid is composed of subunits called capsomeres. The capsid and genome-containing core are together known as the nucleocapsid.
73.8K
Regulation of Nuclear Protein Sorting01:45

Regulation of Nuclear Protein Sorting

3.2K
Nuclear protein sorting regulates nucleus composition and gene expression, crucial for determining the fate of a eukaryotic cell. Hence, the entry and exit of molecules across the nuclear envelope is a tightly controlled process. Nuclear protein sorting can be inhibited by one of the following ways: 1) masking cargo signal sequences, 2) modifying the nuclear receptor's affinity for cargo, 3) controlling the nuclear pore size, 4) retaining the cargo during its transit to the cytosol or the...
3.2K
Size and Structure of Viral Genomes01:26

Size and Structure of Viral Genomes

678
Viral genomes exhibit remarkable diversity in size, structure, and composition, influencing their replication strategies and interactions with host cells. These genomes consist of either DNA or RNA and may be linear or circular. Additionally, they can be single-stranded or double-stranded, with each configuration affecting how the virus propagates within a host. RNA viruses, for instance, generally have smaller genomes than DNA viruses, a factor that contributes to their high mutation rates and...
678

You might also read

Related Articles

Articles linked to this work by shared authors, journal, and citation graph.

Sort by
Same author

Role of TMDs in Class I viral fusion proteins.

Microbiology and molecular biology reviews : MMBR·2026
Same author

Lipid Dynamics in the Amyloid Cascade Hypothesis: Evaluating the Biological Relevance of In Vitro Models.

Chembiochem : a European journal of chemical biology·2026
Same author

Living at the border: biophysical gateways into membrane protein insertion and folding.

Biophysical reviews·2026
Same author

Dermcidin has antiviral activity and protects against influenza.

Proceedings of the National Academy of Sciences of the United States of America·2026
Same author

SARS-CoV-2 membrane protein biogenesis.

bioRxiv : the preprint server for biology·2026
Same author

How lipid composition shapes the nanostructural interaction of tumor biomarker alpha-fetoprotein and bovine serum albumin with model membranes.

Journal of colloid and interface science·2026

Related Experiment Video

Updated: Jan 14, 2026

Production of a SARS-CoV-2 Virus-Like-Particle System to Investigate Viral Life Cycles In Vitro
09:26

Production of a SARS-CoV-2 Virus-Like-Particle System to Investigate Viral Life Cycles In Vitro

Published on: June 6, 2025

1.1K

Structural insights into SARS-CoV-2 nonstructural protein 4 (nsp4) biogenesis.

José M Acosta-Cáceres1, Fabio Lolicato2,3, Laura Gadea-Salom1

  • 1Departament de Bioquímica i Biologia Molecular, Faculty of Biological Sciences, Institut Universitari de Biotecnologia i Biomedicina (BIOTECMED), Universitat de València, Burjassot, Spain.

Protein Science : a Publication of the Protein Society
|October 22, 2025
PubMed
Summary

SARS-CoV-2 nonstructural protein 4 (nsp4) has a defined membrane topology, with an ER lumen-facing N-terminus and a cytoplasm-facing C-terminus. This structure is crucial for forming double-membrane vesicles essential for viral RNA synthesis.

Keywords:
SARS‐CoV‐2coronavirusmembrane insertionnonstructural protein 4topology

More Related Videos

Production of Pseudotyped Particles to Study Highly Pathogenic Coronaviruses in a Biosafety Level 2 Setting
08:40

Production of Pseudotyped Particles to Study Highly Pathogenic Coronaviruses in a Biosafety Level 2 Setting

Published on: March 1, 2019

59.6K
Analysis of Group IV Viral SSHHPS Using In Vitro and In Silico Methods
10:40

Analysis of Group IV Viral SSHHPS Using In Vitro and In Silico Methods

Published on: December 21, 2019

26.4K

Related Experiment Videos

Last Updated: Jan 14, 2026

Production of a SARS-CoV-2 Virus-Like-Particle System to Investigate Viral Life Cycles In Vitro
09:26

Production of a SARS-CoV-2 Virus-Like-Particle System to Investigate Viral Life Cycles In Vitro

Published on: June 6, 2025

1.1K
Production of Pseudotyped Particles to Study Highly Pathogenic Coronaviruses in a Biosafety Level 2 Setting
08:40

Production of Pseudotyped Particles to Study Highly Pathogenic Coronaviruses in a Biosafety Level 2 Setting

Published on: March 1, 2019

59.6K
Analysis of Group IV Viral SSHHPS Using In Vitro and In Silico Methods
10:40

Analysis of Group IV Viral SSHHPS Using In Vitro and In Silico Methods

Published on: December 21, 2019

26.4K

Area of Science:

  • Virology
  • Structural Biology
  • Cell Biology

Background:

  • SARS-CoV-2 requires a replication-transcription complex (RTC) for propagation.
  • Nonstructural protein 4 (nsp4) is a key component of the RTC, involved in endoplasmic reticulum (ER) membrane rearrangements and double-membrane vesicle (DMV) formation.
  • The precise membrane topology and function of nsp4 in SARS-CoV-2 remain incompletely understood.

Purpose of the Study:

  • To elucidate the membrane topology of SARS-CoV-2 nsp4.
  • To understand the structural basis of nsp4's role in viral replication.
  • To investigate the formation of DMVs and associated membrane structures.

Main Methods:

  • Biochemical analysis to determine protein features.
  • Molecular dynamics simulations to predict folding and membrane disposition.
  • Analysis of glycosylation patterns.

Main Results:

  • SARS-CoV-2 nsp4 possesses a partially cleaved signal peptide and three transmembrane segments.
  • The N-terminus is oriented towards the ER lumen, while the C-terminus faces the cytoplasm.
  • A non-canonical glycosylation sequon (N131IC) is not glycosylated in mammalian cells.
  • Molecular dynamics simulations confirmed nsp4's membrane disposition and folding.

Conclusions:

  • The determined membrane topology of nsp4 provides structural insights into its function.
  • nsp4 is essential for ER membrane rearrangements and the formation of DMVs and double-membrane pores.
  • These structures are critical for SARS-CoV-2 RNA replication and transport, advancing understanding of viral propagation mechanisms.