Lipase docking
Switching this lipase on takes two separate marks, not one. The first moves the enzyme from the body of the cell to the surface of the fat droplet. The second, made later and on the droplet itself, turns the enzyme on. Knowing which mark an ingredient makes matters: one that only makes the second is relying on the enzyme having already arrived. A good deal of it has — up to half is already parked there before any signal.
In depth
The first of two marks on the second lipase — the one that moves it to the fat.
What drives it
Lipolysis signal increases it.
The second lipase is switched on in two separate steps, not one — and most evidence only ever shows one of them. 'HSL is phosphorylated by PKA at Ser660, triggering its translocation to lipid droplets; it then forms a stable association with lipid droplets. The subsequent phosphorylation of HSL Ser563 on the surface of the lipid droplets promotes the intrinsic catalytic activity of the lipase' (doi 10.1371/journal.pone.0100559 (PMC4064000) — PRIP Regulates Lipolysis by Modulating the Phosphorylation of Hormone-Sensitive Lipase). ⇒ one mark gets the enzyme to the fat. A different mark turns it on once it is there. This is why 'it raises the active form of the lipase' is an incomplete claim unless the site is named. An ingredient that marks only the switch-on residue is relying on the enzyme having already arrived by other means. And a good deal of it has: 'up to 50% of cellular HSL is LD-associated in the basal state' (PMID 16595669 — Perilipin promotes hormone-sensitive lipase-mediated adipocyte lipolysis via phosphorylation-dependent and -independent mechanisms) — half the lipase is already parked at the droplet before any signal arrives. doi 10.1371/journal.pone.0100559 · PMID 16595669 · PMC4064000
What it drives
It increases Lipase switch-on.
The second lipase is switched on in two separate steps, not one — and most evidence only ever shows one of them. 'HSL is phosphorylated by PKA at Ser660, triggering its translocation to lipid droplets; it then forms a stable association with lipid droplets. The subsequent phosphorylation of HSL Ser563 on the surface of the lipid droplets promotes the intrinsic catalytic activity of the lipase' (doi 10.1371/journal.pone.0100559 (PMC4064000) — PRIP Regulates Lipolysis by Modulating the Phosphorylation of Hormone-Sensitive Lipase). ⇒ one mark gets the enzyme to the fat. A different mark turns it on once it is there. This is why 'it raises the active form of the lipase' is an incomplete claim unless the site is named. An ingredient that marks only the switch-on residue is relying on the enzyme having already arrived by other means. And a good deal of it has: 'up to 50% of cellular HSL is LD-associated in the basal state' (PMID 16595669 — Perilipin promotes hormone-sensitive lipase-mediated adipocyte lipolysis via phosphorylation-dependent and -independent mechanisms) — half the lipase is already parked at the droplet before any signal arrives. doi 10.1371/journal.pone.0100559 · PMID 16595669 · PMC4064000
Blends that modulate it
Each blend page names this pathway and carries the study behind its claim.
See it on the map
Open the causal map to follow this pathway upstream and downstream, arrow by arrow, each with its study.