membrane vesicle

[gocentral]

Could we have the following new term:?

%membrane ; GO:0016020 <membrane vesicle ; GO:nnnnnnn

The dictionary of cell and molecular biology: membrane vesicle: Closed unilamellar shells formed from membranes either in physiological transport processes or else when membranes are mechanically disrupted. They form spontaneously when membrane is broken because the free ends of a lipid bilayer are highly unstable.

Reported by: brendamg

Original Ticket: "geneontology/ontology-requests/616":https://sourceforge.net/p/geneontology/ontology-requests/616

[gocentral]

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This sounds like a very broad term to be adding - would include all vesicles! What enzyme is this the location for? Maybe there's an alternative term you could use.

Original comment by: jl242

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In BRENDA "membrane vesicle" is the location for several enzymes: 1.5.3.9 Reticuline oxidase, cell culture of Berberis sp. 1.6.99.3 NADH2 dehydrogenase, Bacillus subtilis 2.4.1.10 Levansucrase, cell culture of Bacillus amyloliquefaciens and Rahnella aquatilis 2.7.1.107 Diacylglycerol kinase, E.coli 2.7.7.8 Polyribonucleotide nucleotidyltransferase, E.coli 3.5.3.15 protein-arginine deiminase, Porphyromonas gingivalis 3.6.3.12 K+-transporting ATPase, E.coli 3.6.3.16 arsenite-transporting ATPase, E.coli

http://www.chem.rug.nl/enzymology/protocols/chptr4.htm: Isolation of membrane vesicles, pre-extraction of membranes, and formation of hybrid membranes: "Bacterial membrane vesicles are routinely obtained by lysis of osmotically-destabilized cells or rupture of the cells in a French press. Owing to the thick and stable cell wall, lactic acid bacteria are generally much more difficult to lyse than Gram-negative bacteria. Protocols for the isolation of so-called 'right-side-out' and 'inside-out' membrane vesicles of L.lactis and S.thermophilus are given below, but, with minor modifications (temperature, concentration of lytic enzymes, etc.), these methods have proven to be applicable to a wide range of Gram-positive bacteria. "....."The obtained membrane vesicles have a diameter in the range of 0.1-0.3 mm and a large fraction has the membrane proteins in the 'right-side-out' orientation. These membrane vesicles have a specific internal volume of about 4 ml/mg of protein "

Maybe I could use "membrane" or "microsome" instead. Or do you have an umbrella term for all "(membrane) vesicles"?

Original comment by: brendamg

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Hi Marion,

I've had a look at this and it seems as though the expression 'membrane vesicle' is only used when the cells in question have been disrupted experimentally - the vesicles probably don't exist in vivo.

So I'm afraid we're going to have to use the horrible 'cell fraction' terms - I'll add a new term 'vesicular fraction' as a child of 'membrane fraction' and a parent of 'microsome' (which is eukaryote-specific) defined something like:

"Any of the small, heterogeneous, artifactual, vesicular particles that are formed when some cells are homogenized."

would that do?

Original comment by: jl242

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• milestone: --> TermGenie
• assigned_to: nobody --> jl242

Original comment by: jl242

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Hi Jane, we thought it through and it seems to be that there is no other alternative for us as to use this new "vesicular fraction" term (as a child of membrane fraction). It is the same with the "basolateral plasma membrane vesicle" and the sarcoplasmic reticulum vesicle" (maybe we are going keep these terms in our additional commentary).

Original comment by: brendamg

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Added new term 'vesicular fraction ; GO:0042598'.

Original comment by: jl242

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• status: open --> closed-fixed

Original comment by: jl242