MENU
JUL 02, 2015 8:00 AM PDT

Exosome Biogenesis and the Budding of Proteins and Viruses

Speaker

Abstract
Exosomes are small secreted vesicles that have a diameter of ~50-200 nm. Exosomes are enriched for a specific subset of host-derived proteins, nucleic acids, lipids and carbohydrates, though they also incorporate most host cell molecules at baseline levels. Various models of exosome biogenesis have been proposed, but the field lacks the robust mechanistic studies that are needed to obtain a molecular understanding of vesicle secretion. To shed light on this process, our laboratory has taken a cargo-based approach in which we focus on the cis-acting signals that are necessary and sufficient for the budding of specific proteins. These studies have revealed that exosomal proteins are targeted to sites of vesicle budding by a combination of (1) high-order oligomerization and (2) binding to the plasma membrane. In addition, our work supports the hypothesis that the plasma membrane is a major site of exosome budding. Interestingly, HIV and other retroviruses have the same topology, size, and array of host cell molecules as exosomes, raising the possibility that retroviruses bud from infected cells by an exosomal pathway. This hypothesis is supported by the fact that retroviral Gag proteins, their main structural protein, are targeted to sites of exosome budding, bud from cells in association with exosomal cargo proteins, form high-order oligomeric complexes that bind the plasma membrane, and require plasma membrane binding in order to bud from cells. Modeling HIV budding as an exosomal process has led to new lines of experimentation, new sets of data, and new interpretations of decades-old observations, all of which provide increasing support for the hypothesis that HIV and other retroviruses exploit the exosomal machinery to generate infectious viral particles.

Learning Objectives:
  • Various models of exosome biogenesis have been proposed, but the field lacks the robust mechanistic studies that are needed to obtain a molecular understanding of vesicle secretion. Learn how our laboratory has taken a cargo-based approach in which we focus on the cis-acting signals that are necessary and sufficient for the budding of specific proteins.
  • Learn why our work supports the hypothesis that the plasma membrane is a major site of exosome budding

Show Resources
You May Also Like
SEP 14, 2021 7:00 AM PDT
C.E. CREDITS
SEP 14, 2021 7:00 AM PDT
Date: September 14, 2021 Time: 7am PDT, 10am EDT, 4pm CEST A conventional thermal cycler has long been a commodity product in the lab and end-point PCR techniques can be completed almost wit...
MAY 11, 2021 10:00 AM PDT
C.E. CREDITS
MAY 11, 2021 10:00 AM PDT
Date: May 11, 2021 Time: 10:00zm PDT Your samples are some of the most valuable assets in the laboratory. After spending countless hours on extraction and preparation, your conclusions could...
JUL 15, 2021 8:00 AM PDT
C.E. CREDITS
JUL 15, 2021 8:00 AM PDT
Date: July 15, 2021 Time: 8:00am (PDT), 11:00am (EDT) High dimensional full spectrum flow cytometry grants unprecedented access to previously unattainable parameters in cellular biology. Flu...
OCT 12, 2021 9:00 AM PDT
C.E. CREDITS
OCT 12, 2021 9:00 AM PDT
Date: October 12, 2021 Time: 9:00am (PDT), 12:00pm (EDT) SCIEX’s next-generation Biologics Explorer software is an innovative platform for the comprehensive and deep characterization o...
JUN 09, 2021 7:00 AM PDT
C.E. CREDITS
JUN 09, 2021 7:00 AM PDT
Date: June 9, 2021 Time: 09 June 2021, 7am PDT, 10am EDT, 4pm CEST cells with dramatic implications on the validity of past cell culture related research. The fact that at least 509 cell lin...
OCT 20, 2021 10:00 AM PDT
C.E. CREDITS
OCT 20, 2021 10:00 AM PDT
Date: October 20, 2021 Time:10:00am (PDT), 1:00pm (EDT) As the prevalence of Diabetes continues to rise in many areas across the globe, healthcare providers continue to look for methods that...
Loading Comments...
Show Resources