Related Experiment Video
Updated: May 8, 2026
12:48
Purification of the Membrane Compartment for Endoplasmic Reticulum-associated Degradation of Exogenous Antigens in Cross-presentation
Published on: August 21, 2017
Pushing the endogenous envelope
Jamie E Henzy1, Welkin E Johnson
1Biology Department, Boston College, , Chestnut Hill, MA 02467, USA.
Summary
Retroviral envelope genes (env) have distinct evolutionary histories from polymerase genes (pol) due to recombination. Analyzing fusion subunits reveals three main types of retroviral glycoproteins with unique evolutionary paths.
Area of Science:
- Virology
- Evolutionary Biology
- Molecular Biology
Background:
- Retroviral envelope glycoproteins are typically type I viral fusion proteins.
- Fusion subunits of various retroviruses share conserved structures suitable for phylogenetic analysis.
Purpose of the Study:
- To investigate the evolutionary history of retroviral envelope genes (env) separately from polymerase genes (pol).
- To classify retroviral envelope glycoproteins into distinct types based on fusion subunit analysis.
Main Methods:
- Phylogenetic analyses of conserved features in retroviral fusion subunits.
- Sequence comparisons to identify recombination events.
- Tracing identified glycoprotein types in endogenous retroviruses.
Main Results:
- Evidence of numerous recombination events leading to separate evolutionary histories for env and pol genes.
- Identification of three distinct types of retroviral envelope glycoproteins: gamma-type, avian gamma-type, and beta-type.
- Distinct evolutionary dynamics observed for these glycoprotein types within endogenous retroviruses.
Conclusions:
- Retroviral envelope gene sequences provide valuable phylogenetic signals.
- Understanding env evolution is crucial for analyzing cross-species transmissions and novel retroviral lineage generation.
- The distinct evolutionary paths of env highlight the complexity of retrovirus evolution.
Related Concept Videos
00:51Exocytosis
Exocytosis is used to release material from cells. Like other bulk transport mechanisms, exocytosis requires energy.
00:50Exocytosis
Exocytosis is a process that releases molecules outside the cell. Like other bulk transport mechanisms, exocytosis requires energy.
Exocytosis is the opposite of endocytosis, which brings molecules inside the cell. Sometimes, the released materials are signaling molecules. For example, neurons typically use exocytosis to release neurotransmitters. Cells also use exocytosis to insert proteins such as ion channels into their cell membranes, secrete proteins for use in the extracellular matrix, or...
Exocytosis is the opposite of endocytosis, which brings molecules inside the cell. Sometimes, the released materials are signaling molecules. For example, neurons typically use exocytosis to release neurotransmitters. Cells also use exocytosis to insert proteins such as ion channels into their cell membranes, secrete proteins for use in the extracellular matrix, or...
01:18Vesicular Trasport: Endocytosis, Transcytosis and Exocytosis
Vesicular transport is a cellular process that encompasses the engulfment of particles or dissolved substances by cells. It involves endocytosis, transcytosis, and exocytosis.
Endocytosis is a cellular mechanism that involves the inward folding of the cell membrane to create vesicles that capture and transport large drug molecules. This process comprises two distinct methods: pinocytosis (often referred to as "cell drinking") and phagocytosis (often referred to as "cell eating"). Pinocytosis is...
Endocytosis is a cellular mechanism that involves the inward folding of the cell membrane to create vesicles that capture and transport large drug molecules. This process comprises two distinct methods: pinocytosis (often referred to as "cell drinking") and phagocytosis (often referred to as "cell eating"). Pinocytosis is...
01:28Maturation of Endosomes
The early endosome containing internalized molecules matures through transformations in its location, morphology, intraluminal pH, and membrane protein composition. Together, these changes result in a more acidic late endosome that contains multiple intraluminal vesicles; therefore, the late endosome is also called a multivesicular body (MVB).
Changes in location
The maturing endosome moves along microtubules from the periphery of the cell towards the perinuclear region. This movement of the...
Changes in location
The maturing endosome moves along microtubules from the periphery of the cell towards the perinuclear region. This movement of the...
01:16Endocytosis
Eukaryotic cells acquire nutrients for growth and proliferation. Nutrients and other molecules that require degradation are internalized from the extracellular space by a process called endocytosis. The term ‘endocytosis' was first coined by Christian de Duve in 1963.
Endocytosis always begins with the plasma membrane enclosing an incoming molecule to form a transport vesicle which, in some cases, can be coated with a protein called ‘clathrin.' Endocytosed material is either sorted through...
Endocytosis always begins with the plasma membrane enclosing an incoming molecule to form a transport vesicle which, in some cases, can be coated with a protein called ‘clathrin.' Endocytosed material is either sorted through...
01:31Antigen Processing Pathways
MHC molecules are key players in the immune response, enabling T cells to recognize and respond to specific antigens. They are present on the surface of all nucleated cells in the body and are instrumental in presenting antigens to T cells and activating them. T cells recognize the MHC-antigen complex and initiate an immune response. MHC class I and MHC class II are two main types of MHC molecules, each associated with a distinct antigen processing pathway.
MHC Class I: Presenting Endogenous...
MHC Class I: Presenting Endogenous...