Rab6 regulates cell migration and invasion by recruiting Cdc42 and modulating its activity

Abstract

Rab proteins are master regulators of intracellular membrane trafficking but they also contribute to cell division, signaling, polarization and migration. The majority of the works describing the mechanisms used by Rab proteins to regulate cell motility involve intracellular transport of key molecules important for migration. Interestingly, a few studies indicate that Rabs can modulate the activity of Rho GTPases, important regulators for the cytoskeleton rearrangements, but the mechanisms behind this crosstalk are still poorly understood. In this work, we identify Rab6 as a negative regulator of cell migration in vitro and in vivo. We show that loss of Rab6 promotes formation of actin protrusions and influences actomyosin dynamics by upregulating Cdc42 activity and downregulating myosin II phosphorylation. We further provide the molecular mechanism behind this regulation demonstrating that Rab6 interacts with both Cdc42 and Trio, a GEF for Cdc42. In sum, our results uncover a mechanism used by Rab proteins to ensure spatial regulation of Rho GTPase activity for coordination of cytoskeleton rearrangements required in migrating cells.U2OS, HeLa and H1299 cells were grown in Dulbecco´s modified Eagle´s medium (DMEM; Lonza, BioWhittaker). RPE-1 cells were grown DMEM F-12 (Lonza, BioWhittaker). Both DMEM and DMEM F-12 were supplemented with 10 % fetal calf serum (FCS), 2 mM L-glutamine, 100 U/ml penicillin and µg/ml streptomycin. Constructs and antibodies pEGFP-C1 was purchased from BD Biosciences, Clontech. pEGFP-C1 Rab6A wt, pEGFP-C1 Rab6A Q72L and pEGFP-C1 Rab6A T27N were a gift from Marci Scidmore (Addgene plasmid #49469, #49483 and #49484, respectively), [31]. pcDNA3-EGFP-Cdc42-Q61L and pcDNA3-EGFP-Cdc42-T17N were a gift from Gary Bokoch (Addgene plasmid #12986 and #12976, respectively), [32]. pTriEx-mCherry-cdc42 Q61L and the biosensor constructs, pTriEX Cdc42 wt and pTriEX Cdc42 G12V, were a gift from Luis Hodgson (Albert Einstein College of Medicine, NY, USA). mCherry-Cdc42-C-10 was a gift from Michael Davidson (Addgene plasmid # 55014). p CMV-LifeAct-RFP was purchased from Ibidi. pEGFP-C3 Cdc42 wt was a gift from Keith Burridge,

Small GTPase RAB6 deficiency promotes alveolar progenitor cell renewal and attenuates PM2.5-induced lung injury and fibrosis

“…Despite this, the elucidation of the specific molecular mechanism by which RAB6 regulates DKK1 autocrine still requires further investigation. Finally, we cannot completely rule out the possibility that RAB6 regulates AEC2 cell proliferation and self-renewal through other potential targets, such as cell division control protein 42 (CDC42) 25 and kinesin-1 46 , all of which were confirmed as targets of RAB6 by other investigators.…”

“…In addition, RAB6 regulates the secretion of vesicles and affects the growth and development of zebrafish neurons 23 . Moreover, RAB6 protein is widely involved in various physiological activities such as cell adhesion and migration [24][25][26][27] . We have shown that RAB6 is down-regulated in lung cancer tissues, and its overexpression can inhibit cell proliferation and colony formation in non-small cell lung cancer 28 .…”

lncRNA deleted in lymphocytic leukaemia 1 (DLEU1) promotes the migration and invasion of human embryonic trophoblast cells

“…Accumulating evidence has indicated that cell migratory and invasive processes are strongly correlated with significant cytoskeleton remodelling (Fife et al, 2014). CDC42 is a key regulatory protein for the dynamic structures of the cytoskeleton (Vestre et al, 2019). Several recent studies have highlighted that CDC42 is implicated with trophoblast cell migration (Nicola et al, 2008;Fritz et al, 2019).…”

Rab18 regulates focal adhesion dynamics by interacting with kinectin-1 at the endoplasmic reticulum

“…This function is often connected to their role in mediating intracellular transport, but can also be associated with their ability to regulate cytoskeleton dynamics (Borg et al, 2014;Kjos et al, 2018;Lanzetti et al, 2004;Linford et al, 2012;Palamidessi et al, 2008). Indeed, Rab proteins can influence cytoskeleton dynamics, for example through crosstalk with Rho GTPases (Borg et al, 2014;Bravo-Cordero et al, 2016;Chevallier et al, 2009;Jian et al, 2016;Margiotta et al, 2017;Palamidessi et al, 2008;Vestre et al, 2019).…”