Rab35 Targeting to the Plasma Membrane Is Dependent on the C-terminal Polybasic Cluster

Abstract

Rab35, a member of the Rab GTPase family, has been implicated in various cellular processes including cell motility and membrane trafficking. Although Rab35 is localized to the plasma membrane, Rab proteins that are identified to have high sequence homology with Rab35 exhibit distinct subcellular localization patterns. Comparing the amino acid sequences between Rab35 and its family members revealed a significant variation in an approximate 30-amino acid region of the C-terminus. This suggests that this region determines the subcellular localization of individual Rab proteins. To confirm this hypothesis, we constructed Rab35–Rab10 chimera proteins by exchanging their C-terminal domains with one another. Confocal microscopy of RAW264 cells expressing EGFP-fused Rab35–Rab10 chimeras has indicated that the C-terminal region of Rab35 is critical for its plasma membrane localization. Furthermore, we were able to determine that a basic amino acid cluster exists in the C-terminal region of Rab35 and that Rab35 localization shifts to the Golgi membrane when the number of basic amino acids in this region is reduced. Thus, it is likely that the approximate 30-amino acid C-terminal region containing basic clusters is responsible for Rab35 plasma membrane localization and that its preferential localization depends on the number of basic amino acids.

Rab10-Positive Tubular Structures Represent a Novel Endocytic Pathway That Diverges From Canonical Macropinocytosis in RAW264 Macrophages

“…However, we did not observe SNX1 localization on Rab10-positive compartments (Figure 7E, Supplementary Movie 13). To determine the destination of Rab10-positive tubules, we observed the relationship between the Rab10-positive tubules and the Golgi complex using EGFP-Rab35-4E, a Golgi marker that was created by a C-terminal mutation of Rab35 (32). The front end of Rab10positive tubules appeared to reach out to the center of the Golgi region (Supplementary Movie 13).…”

Rab35 GTPase positively regulates endocytic recycling of cardiac KATP channels

“…Rab35 contains an evolutionarily conserved polybasic C-terminal tail and localizes both at the intracellular vesicles and plasma membrane [ 22 , 23 ]. Rab35 plays an important role in promoting endocytic recycling of various cargoes, including Ca 2+ -activated K + channel KCa2.3 in terms of ion channels.…”