Related Experiment Video

Updated: Aug 19, 2026

Visualization of HIV-1 Gag Binding to Giant Unilamellar Vesicle (GUV) Membranes
08:21

Visualization of HIV-1 Gag Binding to Giant Unilamellar Vesicle (GUV) Membranes

Published on: July 28, 2016

Unmyristylated Moloney murine leukemia virus Pr65gag is excluded from virus assembly and maturation events

A M Schultz1, A Rein

  • 1Laboratory of Molecular Virology and Carcinogenesis, NCI-Frederick Cancer Research Facility, Frederick, Maryland 21701.

Journal of Virology
|May 1, 1989
PubMed

Insights

Myristylation of the Moloney murine leukemia virus (MuLV) gag precursor polyprotein is essential for its membrane association, processing, and virus particle assembly. Without this modification, the gag protein fails to mature or incorporate into new virions.

Area of Science:

  • Virology
  • Molecular Biology
  • Cellular Biology

Background:

  • The gag precursor polyprotein (Pr65gag) of Moloney murine leukemia virus (MuLV) is typically modified by N-terminal myristylation.
  • Previous studies indicated that Pr65gag lacking the myristylation site does not associate with cellular membranes or assemble into virus particles.

Purpose of the Study:

  • To investigate the role of myristylation in the processing, assembly, and maturation of MuLV Pr65gag.
  • To determine if myristylation is a prerequisite for MuLV assembly and budding.

Main Methods:

  • Analysis of a mutant MuLV Pr65gag lacking the N-terminal myristylation site.
  • Cellular fractionation and sedimentation assays in detergent-free extracts.
  • Infection of cells expressing the mutant Pr65gag with wild-type MuLV.

Main Results:

  • The mutant Pr65gag, lacking myristylation, was not cleaved into mature gag products within the cell.
  • The mutant Pr65gag sedimented as a free 65-kilodalton monomer.
  • Even in cells productively infected with wild-type MuLV, the mutant Pr65gag was not processed or incorporated into newly formed virions.

Conclusions:

  • Myristylation of MuLV Pr65gag is crucial for its proper processing and maturation.
  • Myristate-mediated membrane association appears to be a critical initial step for MuLV assembly.
  • This membrane association may also be involved in the budding process of MuLV.

More Related Videos

MicroRNA-based Regulation of Picornavirus Tropism09:05

MicroRNA-based Regulation of Picornavirus Tropism

Published on: February 6, 2017

Paramyxoviruses for Tumor-targeted Immunomodulation: Design and Evaluation Ex Vivo12:42

Paramyxoviruses for Tumor-targeted Immunomodulation: Design and Evaluation Ex Vivo

Published on: January 7, 2019

Related Concept Videos

Leaky Scanning02:28

Leaky Scanning

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 stands for...
Intralumenal Vesicles and Multivesicular Bodies01:38

Intralumenal Vesicles and Multivesicular Bodies

Intraluminal vesicles (ILVs) are small vesicles 50-80 nm in diameter formed during the maturation of early endosomes. A specialized endosome containing numerous ILVs is called a multivesicular body (MVB). ILVs contain internalized molecules such as antigens, nucleic acids, proteins, and metabolites. Some of these molecules are released from the MVBs inside exosomes and are transported to other cells. Other MVBs contain molecules that are retained in the ILVs and are later degraded within the...
Subviral Agents01:29

Subviral Agents

Subviral agents are infectious entities that resemble viruses but lack one or more viral components, such as a capsid or essential replication machinery. These agents include viroids, prions, and satellites, each possessing distinct structural and functional characteristics that influence their mode of infection and replication.Viroids are the simplest subviral agents, consisting of circular, single-stranded RNA molecules without a protein coat. They exclusively infect plants, relying entirely...
Inhibitors of Virion Maturation and Assembly01:19

Inhibitors of Virion Maturation and Assembly

As part of their replication cycle, certain viruses synthesize long precursor proteins called polyproteins within infected host cells. In human immunodeficiency virus (HIV), two major polyproteins are produced: Gag and Gag-Pol. The Gag polyprotein supplies the structural components of the virus, while Gag-Pol includes essential viral enzymes such as reverse transcriptase, integrase, and protease. After synthesis, these polyproteins move to the host cell membrane, where they assemble into an...