Tuesday, March 12, 2019
Analysis of the stoichiometry of human acetylation?
Does the word "stoichiometry" give you awful flashbacks to adolescence? Have you avoided thinking about it by only using it in sentences like "phosphorylation only occurs at low stoichiometry" and not saying anything further? Time to fix that, because this is the topic in a biologically meaningful context from a brilliant and totally new (at least to me?) approach to understanding acetylation!
Are these sentences terrible? Daylight savings time is dumb and I feel even less coherent than usual.
How does acetylation in human cells happen? 2 ways
1) Tightly controlled enzymatic acetylation/deacetylation (acetyltransferase things?)
2) Non-enzymatic reactions on any available lysine from Acetyl-CoA just floating around.
This group described the abundance of #2 to be at a level where the super important tightly controlled cellular regulation focused #1 ends up being something really hard to define using our traditional method (they actually said "needle in a haystack" which is depressing)
And that's why they did a ton of innovative work to try and figure out which acetylations are which!
I'm not smart enough this morning (possibly ever, honestly) to explain what they did beyond the use of serial diluted SILAC (smart!) antibody enrichment of acetylation sites in conjunction with forcing chemical acetylation with 1M(!) acetyl-phosphate and doing loads of smart maths! (A QE HF was used for all the mass spec stuff and MaxQuant for data analysis)
All the data will be available (it isn't yet) at PRIDE here. (PXD009994)
What do we get? A massively better understanding of how and where and when acetylation occurs and which ones we REALLY need to pay attention to when trying to decide --> is this a downstream process caused by a normal (or glitchy) evolved mechanism OR is it just a highly abundant protein that looks important because of chemical acetylation effects?