Limits...
Direct observation of membrane insertion by enveloped virus matrix proteins by phosphate displacement.

Neuman BW, Kiss G, Al-Mulla HM, Dokland T, Buchmeier MJ, Weikl T, Schley D - PLoS ONE (2013)

Bottom Line: Enveloped virus release is driven by poorly understood proteins that are functional analogs of the coat protein assemblies that mediate intracellular vesicle trafficking.We used differential electron density mapping to detect membrane integration by membrane-bending proteins from five virus families.This demonstrates that virus matrix proteins replace an unexpectedly large portion of the lipid content of the inner membrane face, a generalized feature likely to play a role in reshaping cellular membranes.

View Article: PubMed Central - PubMed

Affiliation: School of Biological Sciences, University of Reading, Reading, Berkshire, United Kingdom. b.w.neuman@reading.ac.uk

ABSTRACT
Enveloped virus release is driven by poorly understood proteins that are functional analogs of the coat protein assemblies that mediate intracellular vesicle trafficking. We used differential electron density mapping to detect membrane integration by membrane-bending proteins from five virus families. This demonstrates that virus matrix proteins replace an unexpectedly large portion of the lipid content of the inner membrane face, a generalized feature likely to play a role in reshaping cellular membranes.

Show MeSH

Related in: MedlinePlus

Presence of matrix proteins at the virion surface is necessary to maintain elongated virus shapes.(A) Shape and perimeter length are shown for 252 Influenza A virus particles and 66 GP vesicles. Coefficients of determination and statistical confidence measures are shown for virus particles and GP vesicles of Lymphocytic choriomeningitis virus (LCMV), Tacaribe virus (TCRV) and Influenza A virus (FLUAV), and for empty vesicles of cellular origin (B).
© Copyright Policy
Related In: Results  -  Collection


getmorefigures.php?uid=PMC3585246&req=5

pone-0057916-g002: Presence of matrix proteins at the virion surface is necessary to maintain elongated virus shapes.(A) Shape and perimeter length are shown for 252 Influenza A virus particles and 66 GP vesicles. Coefficients of determination and statistical confidence measures are shown for virus particles and GP vesicles of Lymphocytic choriomeningitis virus (LCMV), Tacaribe virus (TCRV) and Influenza A virus (FLUAV), and for empty vesicles of cellular origin (B).

Mentions: Viruses, GP vesicles and empty vesicles were measured to determine whether the shape of the virus membrane was altered in the presence of matrix proteins. Virus-sized unilamellar vesicles in these micrographs were generally spherical as expected [7], with an average ratio of 1.05±0.10 for the largest to the smallest visible diameter. Three of the eleven viruses studied showed a statistically significant correlation between virus size and shape, ranging from small round viruses to large sausage-shaped particles with maximum diameters up to seven times as long as the shortest diameter (Fig. 2A), demonstrating that membrane shape is altered when virus proteins are present. The viruses selected here are all relatively simple, in that matrix proteins and the transmembrane anchors of the surface glycorproteins are the only virus components in direct contact with the membrane. The correlation between size and shape was absent or reduced for GP vesicles (Fig. 2B), demonstrating that the matrix proteins of these viruses are necessary for membrane bending, as reported previously [8].


Direct observation of membrane insertion by enveloped virus matrix proteins by phosphate displacement.

Neuman BW, Kiss G, Al-Mulla HM, Dokland T, Buchmeier MJ, Weikl T, Schley D - PLoS ONE (2013)

Presence of matrix proteins at the virion surface is necessary to maintain elongated virus shapes.(A) Shape and perimeter length are shown for 252 Influenza A virus particles and 66 GP vesicles. Coefficients of determination and statistical confidence measures are shown for virus particles and GP vesicles of Lymphocytic choriomeningitis virus (LCMV), Tacaribe virus (TCRV) and Influenza A virus (FLUAV), and for empty vesicles of cellular origin (B).
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3585246&req=5

pone-0057916-g002: Presence of matrix proteins at the virion surface is necessary to maintain elongated virus shapes.(A) Shape and perimeter length are shown for 252 Influenza A virus particles and 66 GP vesicles. Coefficients of determination and statistical confidence measures are shown for virus particles and GP vesicles of Lymphocytic choriomeningitis virus (LCMV), Tacaribe virus (TCRV) and Influenza A virus (FLUAV), and for empty vesicles of cellular origin (B).
Mentions: Viruses, GP vesicles and empty vesicles were measured to determine whether the shape of the virus membrane was altered in the presence of matrix proteins. Virus-sized unilamellar vesicles in these micrographs were generally spherical as expected [7], with an average ratio of 1.05±0.10 for the largest to the smallest visible diameter. Three of the eleven viruses studied showed a statistically significant correlation between virus size and shape, ranging from small round viruses to large sausage-shaped particles with maximum diameters up to seven times as long as the shortest diameter (Fig. 2A), demonstrating that membrane shape is altered when virus proteins are present. The viruses selected here are all relatively simple, in that matrix proteins and the transmembrane anchors of the surface glycorproteins are the only virus components in direct contact with the membrane. The correlation between size and shape was absent or reduced for GP vesicles (Fig. 2B), demonstrating that the matrix proteins of these viruses are necessary for membrane bending, as reported previously [8].

Bottom Line: Enveloped virus release is driven by poorly understood proteins that are functional analogs of the coat protein assemblies that mediate intracellular vesicle trafficking.We used differential electron density mapping to detect membrane integration by membrane-bending proteins from five virus families.This demonstrates that virus matrix proteins replace an unexpectedly large portion of the lipid content of the inner membrane face, a generalized feature likely to play a role in reshaping cellular membranes.

View Article: PubMed Central - PubMed

Affiliation: School of Biological Sciences, University of Reading, Reading, Berkshire, United Kingdom. b.w.neuman@reading.ac.uk

ABSTRACT
Enveloped virus release is driven by poorly understood proteins that are functional analogs of the coat protein assemblies that mediate intracellular vesicle trafficking. We used differential electron density mapping to detect membrane integration by membrane-bending proteins from five virus families. This demonstrates that virus matrix proteins replace an unexpectedly large portion of the lipid content of the inner membrane face, a generalized feature likely to play a role in reshaping cellular membranes.

Show MeSH
Related in: MedlinePlus