Related Experiment Video

Updated: Jun 3, 2026

Phagosome Migration and Velocity Measured in Live Primary Human Macrophages Infected with HIV-1
07:32

Phagosome Migration and Velocity Measured in Live Primary Human Macrophages Infected with HIV-1

Published on: September 5, 2016

M-Sec promotes the production of infectious HIV-1 virus through the exocyst complex in macrophages

Reem M Mahmoud1,2, Masateru Hiyoshi3, Randa A Abdelnaser1

  • 1Division of Infection & Hematopoiesis, Joint Research Center for Human Retrovirus Infection, Kumamoto University, Kumamoto, Japan.

Plos Pathogens
|June 1, 2026
PubMed

Insights

The cellular protein M-Sec enhances human immunodeficiency virus type 1 (HIV-1) production and infectivity in macrophages. It regulates viral particle formation and incorporation of viral proteins, aiding HIV-1 transmission.

Area of Science:

  • Virology
  • Cell Biology
  • Immunology

Background:

  • The cellular protein M-Sec is known to promote human immunodeficiency virus type 1 (HIV-1) transmission in macrophages.
  • The precise mechanism by which M-Sec influences HIV-1 production and infectivity remains incompletely understood.

Purpose of the Study:

  • To elucidate the mechanism underlying M-Sec's role in HIV-1 production and transmission.
  • To investigate the impact of M-Sec on viral particle formation, protein incorporation, and infectivity.

Main Methods:

  • Knockdown and overexpression of M-Sec in infected macrophages.
  • Analysis of Gag puncta formation and Gag/Env co-localization.
  • Quantification of viral Env incorporation and infectivity.
  • Investigation of M-Sec's interactions with phosphatidylinositol 4,5-bisphosphate (PIP2), Ral, and the exocyst complex.

Main Results:

  • M-Sec knockdown impaired Gag puncta formation, Gag/Env co-localization, Env incorporation, and viral infectivity.
  • M-Sec overexpression enhanced Gag puncta formation, Gag/Env co-localization, Env incorporation, and viral infectivity.
  • M-Sec's regulation of HIV-1 requires PIP2, Ral, and the exocyst complex, which are also involved in M-Sec-mediated plasma membrane protrusions.

Conclusions:

  • M-Sec significantly promotes infectious HIV-1 production by influencing viral structural protein organization and Env incorporation.
  • M-Sec facilitates HIV-1 transmission by modulating both cellular structures and viral production pathways via PIP2, Ral, and the exocyst complex.

More Related Videos

An In vitro Co-infection Model to Study Plasmodium falciparum-HIV-1 Interactions in Human Primary Monocyte-derived Immune Cells07:39

An In vitro Co-infection Model to Study Plasmodium falciparum-HIV-1 Interactions in Human Primary Monocyte-derived Immune Cells

Published on: August 15, 2012

Visualizing Non-lytic Exocytosis of Cryptococcus neoformans from Macrophages Using Digital Light Microscopy10:02

Visualizing Non-lytic Exocytosis of Cryptococcus neoformans from Macrophages Using Digital Light Microscopy

Published on: October 21, 2014

Related Concept Videos

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...
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...
Overview of Secretory Vesicles01:33

Overview of Secretory Vesicles

Secretory vesicles, also known as dense core vesicles (DCVs), are membrane-bound vesicles that transport secretory proteins, such as hormones or neurotransmitters. Regulated secretory vesicles transport proteins from the trans-Golgi network to the exterior of the cell. Proteins present in regulated secretory vesicles are required to be rapidly exocytosed in large amounts upon a specific stimulus.
Various proteins regulate the aggregation of molecules inside the secretory vesicles. Chromogranins...
Cytomegalovirus Disease01:27

Cytomegalovirus Disease

Cytomegalovirus (CMV) disease is caused by human cytomegalovirus, a double-stranded DNA virus of the Herpesviridae family. While primary CMV infection is often asymptomatic in immunocompetent individuals, the virus can cause severe disease in neonates and immunocompromised patients. CMV is the most common cause of congenital viral infection in the United States, and a major pathogen in solid organ and hematopoietic stem cell transplant recipients.CMV is transmitted via bodily fluids, sexual...