Rabaptin5 is recruited to endosomes by Rab4 and Rabex5 to regulate endosome maturation

Kälin, Simone and Hirschmann, David T. and Buser, Dominik P. and Spiess, Martin. (2015) Rabaptin5 is recruited to endosomes by Rab4 and Rabex5 to regulate endosome maturation. Journal of Cell Science, 128 (22). pp. 4126-4137.

PDF - Published Version

Official URL: http://edoc.unibas.ch/41194/

Downloads: Statistics Overview


Rab GTPases control membrane identity, fusion, and transport by interaction with effector proteins. Effectors that influence the activation/inactivation cycle of their own or other Rabs contribute to the timely conversion of Rab identities. Rab5 and its effector Rabaptin5 are generally considered the prime example for a positive feedback loop in which Rab5·GTP recruits Rabaptin5 complexed to Rabex5, the GDP/GTP exchange factor of Rab5, to early endosomes, thus maintaining the membrane's Rab5 identity. By deletion analysis, we found membrane recruitment of Rabaptin5 to require binding to Rab4 and Rabex5, but not Rab5. Deletion of either one of two Rab5 binding domains or silencing of Rab5 expression did not affect Rabaptin5 recruitment, but produced giant endosomes with early and late endosomal characteristics. The results contradict feedback activation of Rab5 and instead indicate that Rabaptin5 is recruited by Rabex5 recognizing ubiquitinated cargo and by Rab4 to activate Rab5 in a feed-forward manner.
Faculties and Departments:05 Faculty of Science > Departement Biozentrum > Growth & Development > Biochemistry (Spiess)
UniBasel Contributors:Spiess, Martin
Item Type:Article, refereed
Article Subtype:Research Article
Publisher:Company of Biologists
Note:Publication type according to Uni Basel Research Database: Journal article
Identification Number:
edoc DOI:
Last Modified:09 Nov 2017 15:42
Deposited On:23 Aug 2016 08:03

Repository Staff Only: item control page