BCAS3 regulates WIPI2b via a direct interaction in the ATG16L1-binding cleft

BCAS3 directly binds WIPI2b in the ATG16L1-binding cleft with low micromolar affinity, enabling BCAS3/PHAF1-driven recruitment of WIPI2b to membranes via PtdIns3P.

• Why it matters: Autophagosome initiation depends on WIPI2b recruitment to PtdIns3P-rich membranes, but how WIPI2b membrane association is regulated beyond ATG16L1 is unclear.
• What they did: The study identifies BCAS3 as a WIPI2b interactor and uses a BCAS3 peptide binding assay to measure low micromolar affinity for the ATG16L1-binding cleft, then tests membrane recruitment with BCAS3 and PHAF1.
• The result: BCAS3 and PHAF1 induce WIPI2b membrane recruitment through BCAS3’s interaction with PtdIns3P, challenging the idea that ATG16L1 is the only confirmed binder in this region.

AI summary of the abstract · may contain errors · not medical advice · read the paper.