Pathway link PTEN-PI3K

PTEN ⊣ PI3K

PTEN inhibits PI3K.

PTEN erases the lipid signal that PI3K makes. Losing PTEN is one of the most common ways cancers keep this whole pathway switched on without any signal from outside.

PTEN erases PIP3, undoing PI3K. Losing PTEN is one of the commonest ways a tumour leaves this whole axis switched on without an upstream signal.

The conditions it holds under

The arrow is drawn PTEN -> PI3K for readability, but PTEN does not act on the PI3K enzyme. It dephosphorylates PIP3, PI3K's lipid product, so the effect on PI3K signalling is indirect and the edge is a compressed one whose hidden intermediate is PIP3. The canonical biochemical demonstration (Maehama & Dixon, J Biol Chem 1998, PMID 9593664) sits outside this corpus: purified recombinant PTEN dephosphorylates PtdIns(3,4,5)P3 specifically at position 3, and in the same paper PTEN overexpression reduced insulin-induced PIP3 without affecting insulin-induced PI3K activation. The cancer-genetics support in-corpus is mouse (GUE2009).

The 'inhibits' label describes the net effect on signalling, not the enzyme itself: PTEN does not inhibit PI3K catalytically, and Maehama & Dixon reported PI3K activation itself unchanged. PTEN dephosphorylates PIP3, PI3K's lipid product, erasing the signal downstream of the enzyme rather than blocking the enzyme's activity.

Time it takes

seconds

Step

indirect (through steps not drawn here)

Measured in

mouse

Where in the cell

plasma membrane

Reaches people?

plausible in people, not shown directly

How settled

settled in the literature

Studies behind it

Points the other way

No study in the Atlas contradicts this link. That means none in this curated set, not none in the literature.

Who has checked this

Checked by

No researcher outside the project has checked this link yet.

Curator sign-off

Not signed off yet. This link was drafted with AI help and has not been reviewed link by link; treat it as a proposal until it is.

Curated by

Oliver Barton, with AI help for drafting; see how links are checked.

“Inhibits” describes the effect on the target's activity, not on how much of it there is.

“How settled” describes how far researchers in the field agree. It is not the same as the sign-off above, which only says whether a named curator has checked this page.

If this link rests on your own work: a click on “This looks right” below, or a short note through “Report an error”, helps us more than anything else on this page.

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