obsoletion, sterol esterification terms

[ValWood]

GO:NEW lanosterol esterification Biological Process

Definition A lipid modification process in which a ergosterol ester is formed by the combination of a carboxylic acid (often a fatty acid) and a ergosterol molecule. Acknowledgement

GO:NEW ergosterol esterification Biological Process

Definition A lipid modification process in which a ergosterol ester is formed by the combination of a carboxylic acid (often a fatty acid) and a ergosterol molecule. Acknowledgement

Parent GO:0034434 sterol esterification

Ref

From the paper I am reading cells lacking Are1p (which mainly esterifies lanosterol [5], but has limited activity in aerobic conditions) and Are2p (which mainly esterifies ergosterol [5])

5 is: Zweytick D, Leitner E, Kohlwein SD, Yu C, Rothblatt J, Daum G. Contribution of Are1p and Are2p to steryl ester synthesis in the yeast saccharomyces cerevisiae. European Journal of Biochemistry. 2000; 267:1075–1082. [PubMed: 10672016]

[ValWood]

You could add F-P links to these

GO:0034738    lanosterol O-acyltransferase activity | is_a GO:0034737    ergosterol O-acyltransferase activity | is_a GO:0034736    cholesterol O-acyltransferase activity

[ValWood]

Actually, maybe we shouldn't have GO:0034434 sterol esterification if it's single step, it's a function in the process ontology?

[deustp01]

Would multiple parallel (rather than sequential) reactions be OK, as there are multiple sterols and multiple acyl groups, so many ways to esterify, even though any one esterification takes a single step?

[alanbridge]

Sounds more like a reaction? Here's a couple of examples (with acyl-CoA as donor, which is probably one of the most likely, but perhaps other donors are possible too?) from Rhea, which seem to map OK to the MFs you mention

GO:0034737 ergosterol O-acyltransferase activity an acyl-CoA + ergosterol = CoA + ergosteryl ester https://www.rhea-db.org/reaction?id=33483

GO:0034738 lanosterol O-acyltransferase activity an acyl-CoA + lanosterol = CoA + lanosteryl ester https://www.rhea-db.org/reaction?id=33479

BTW, hope you are doing OK in the lockdown!

[ValWood]

Would multiple parallel (rather than sequential) reactions be OK, as there are multiple sterols and multiple acyl groups, so many ways to esterify, even though any one esterification takes a single step?

Good point. Maybe a single esterification grouping term would. be sufficient

BP GO:0034434 sterol esterification -- MF GO:0034738 lanosterol O-acyltransferase activity | is_a -- MF GO:0034737 ergosterol O-acyltransferase activity | is_a -- MF GO:0034736 cholesterol O-acyltransferase activity

If we did this, then to be consistent we would merge GO:0034435 cholesterol esterification into GO:0034434 sterol esterification

the advantage of the complete way is that the yeast annotation to GO:0034737 ergosterol O-acyltransferase activity would become annotated to "ergosterol metabolism" and I would not need to make concurrent annotations.

but GO:0034737 ergosterol O-acyltransferase activity could also have an F-P link to "ergosterol metabolism" so that is solvable too. and GO:0034736 cholesterol O-acyltransferase activity part_of to cholesterol metabolic process.

[ValWood]

@hdrabkin this can probably close? Can do MF involved in BP

[hdrabkin]

Yes, the process terms you suggested do seem to all be one step keyed to the mf term?

[hdrabkin]

BP GO:0034434 sterol esterification is stil a single step yes? In fact every from steroid esterification down? Obsolete?

[hdrabkin]

'cholesterol esterification' 'negative regulation of cholesterol esterification' 'positive regulation of cholesterol esterification' 'regulation of cholesterol esterification' 'steroid esterification' 'sterol esterification'

[pgaudet]

Lets also obsolete

• [x] GO:0034207 steroid acetylation: 0 EXP
• [x] GO:0034209 sterol acetylation 1 EXP
• [x] GO:0034208 steroid deacetylation: 0 EXP
• [x] GO:0034210 sterol deacetylation: 1 EXP

I added the 2 annotations to the spreadsheet

https://docs.google.com/spreadsheets/d/1nvfCX3MejcsA_OuUFH113Xlc8MOpoRB7ZDMpkwuBFkk/edit#gid=0

Thanks, Pascale

[pgaudet]

Forgot to mention, the annotations are by SGD @srengel

[srengel]

SGD done.