Rap2 function requires palmitoylation and recycling endosome localization.

Yukiko Uechi, Maitsetseg Bayarjargal, Masato Umikawa, Minoru Oshiro, Kimiko Takei, Yoshito Yamashiro, Tsuyoshi Asato, Shogo Endo, Ryo Misaki, Tomohiko Taguchi, Ken-ichi Kariya

Division of Cell Biology, Graduate School of Medicine, University of the Ryukyus, Okinawa, Japan.

Biochemical and biophysical research communications 2009 Jan 23

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Rap2A, Rap2B, and Rap2C are Ras-like small G proteins. The role of their post-translational processing has not been investigated due to the lack of information on their downstream signaling. We have recently identified the Traf2- and Nck-interacting kinase (TNIK), a member of the STE20 group of mitogen-activated protein kinase kinase kinase kinases, as a specific Rap2 effector. Here we report that, in HEK293T cells, Rap2A (farnesylated) and Rap2C (likely farnesylated), but not Rap2B (geranylgeranylated), require palmitoylation for membrane-association and TNIK activation, whereas all Rap2 proteins, including Rap2B, require palmitoylation for induction of TNIK-mediated phenotype, the suppression of cell spreading. Furthermore, we report for the first time that, in COS-1 cells, Rap2 proteins localize, and recruit TNIK, to the recycling endosomes, but not the Golgi nor the endoplasmic reticulum, in a palmitoylation-dependent manner. These observations implicate the involvement of palmitoylation and recycling endosome localization in cellular functions of Rap2 proteins.

Citation

Yukiko Uechi, Maitsetseg Bayarjargal, Masato Umikawa, Minoru Oshiro, Kimiko Takei, Yoshito Yamashiro, Tsuyoshi Asato, Shogo Endo, Ryo Misaki, Tomohiko Taguchi, Ken-ichi Kariya. Rap2 function requires palmitoylation and recycling endosome localization. Biochemical and biophysical research communications. 2009 Jan 23;378(4):732-7