Rabaptin-5 alpha/rabaptin-4 serves as a linker between rab4 and gamma(1)-adaptin in membrane recycling from endosomes

M Deneka, M Neeft, [No Value] Popa, M van Oort, H Sprong, [No Value] Oorschot, J Klumperman, P Schu, P van der Sluijs*

*Bijbehorende auteur voor dit werk

OnderzoeksoutputAcademicpeer review

72 Citaten (Scopus)

Samenvatting

Rab4 regulates recycling from early endosomes. We investigated the role of the rab4 effector rabaptin-5alpha and its putative partner gamma(1)-adaptin in membrane recycling. We found that rabaptin-5alpha forms a ternary complex with the gamma(1)-sigma(1) subcomplex of AP-1, via a direct interaction with the gamma(1)-subunit. The binding site for gamma(1)-adaptin is in the hinge region of rabaptin-5alpha, which is distinct from rab4- and rab5-binding domains. Endogenous or ectopically expressed gamma(1)- adaptin localized to both the trans-Golgi network and endosomes. Co-expressed rabaptin-5alpha and gamma(1)-adaptin, however, co-localized in a rab4-dependent manner on recycling endosomes. Transfection of rabaptin-5alpha caused enlarged endosomes and delayed recycling of transferrin. RNAi of rab4 had an opposing effect on transferrin recycling. Collectively, our data show that rab4-GTP acts as a scaffold for a rabaptin-5alpha- gamma(1)-adaptin complex on recycling endosomes and that interactions between rab4, rabaptin-5alpha and gamma(1)-adaptin regulate membrane recycling.

Originele taal-2English
Pagina's (van-tot)2645-2657
Aantal pagina's13
TijdschriftEMBO Journal
Volume22
Nummer van het tijdschrift11
StatusPublished - 2-jun-2003

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