Journal of Biological Chemistry
Volume 280, Issue 37, 16 September 2005, Pages 32356-32361
Journal home page for Journal of Biological Chemistry

Membrane Transport, Structure, Function, and Biogenesis
Possible Role of Direct Rac1-Rab7 Interaction in Ruffled Border Formation of Osteoclasts*

https://doi.org/10.1074/jbc.M414213200Get rights and content
Under a Creative Commons license
open access

Rab7 has been shown to regulate the late steps of the endocytic pathway. In bone-resorbing osteoclasts, it is involved in formation of the ruffled border, which is a late endosomal-like compartment in the plasma membrane. Here we report a new Rab7-interacting protein, Rac1, another small GTPase protein that binds to the GTP-form of Rab7 as found with a two-hybrid system. We demonstrate further that Rab7 colocalizes with Rac1 at the fusion zone of the ruffled border in bone-resorbing osteoclasts. In other cell types, such as fibroblast-like cells, partial colocalization is perinuclear. Because Rac1 is known to control the actin cytoskeleton through its effectors, the Rab7-Rac1 interaction may mediate late endosomal transport between microtubules and microfilaments enabling endosomal vesicles to switch tracks and may thus also regulate ruffled border formation in osteoclasts.

Cited by (0)

The nucleotide sequence(s) reported in this paper has been submitted to the GenBank™/EBI Data Bank with accession number(s) AY491395.

*

The costs of publication of this article were defrayed in part by the payment of page charges. This article must therefore be hereby marked “advertisement” in accordance with 18 U.S.C. Section 1734 solely to indicate this fact.