CtBP3/BARS drives membrane fission in dynamin-independent transport pathways

Bonazzi, Matteo; Spanò, Stefania; Turacchio, Gabriele; Cericola, Claudia; Valente, Carmen; Colanzi, Antonino; Kweon, Hee Seok; Hsu, Victor; Polishchuck, Elena V.; Polishchuck, Roman; Sallese, Michele; Pulvirenti, Teodoro; Corda, Daniela; Luini, Alberto

doi:10.1038/ncb1260

Cited by 158 publications

(181 citation statements)

References 48 publications

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“…Nonetheless, there is a strong consensus for a requirement of Dyn2 in the export of the apical plasma membrane marker, p75/neurotrophin receptor, from the TGN (Kreitzer et al, 2000;Bonazzi et al, 2005). However, because these findings are based on overexpression of dominant-negative dynamin mutants, it is not known whether this represents an isoformspecific function of Dyn2.…”

Section: Dyn2mentioning

confidence: 77%

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Isoform and Splice-Variant Specific Functions of Dynamin-2 Revealed by Analysis of Conditional Knock-Out Cells

Liu

Surka

Schroeter

et al. 2008

MBoC

125

163

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Dynamin (Dyn) is a multifunctional GTPase implicated in several cellular events, including endocytosis, intracellular trafficking, cell signaling, and cytokinesis. The mammalian genome encodes three isoforms, Dyn1, Dyn2, and Dyn3, and several splice variants of each, leading to the suggestion that distinct isoforms and/or distinct splice variants might mediate distinct cellular functions. We generated a conditional Dyn2 KO cell line and performed knockout and reconstitution experiments to explore the isoform-and splice variant specific cellular functions of ubiquitously expressed Dyn2. We find that Dyn2 is required for clathrin-mediated endocytosis (CME), p75 export from the Golgi, and PDGFstimulated macropinocytosis and cytokinesis, but not for other endocytic pathways. Surprisingly, CME and p75 exocytosis were efficiently rescued by reintroduction of Dyn2, but not Dyn1, suggesting that these two isoforms function differentially in vesicular trafficking in nonneuronal cells. Both isoforms rescued macropinocytosis and cytokinesis, suggesting that dynamin function in these processes might be mechanistically distinct from its role in CME. Although all four Dyn2 splice variants could equally restore CME, Dyn2ba and -bb were more effective at restoring p75 exocytosis. This splice variant specificity correlated with their differential targeting to the Golgi. These studies reveal isoform and splice-variant specific functions for Dyn2. INTRODUCTIONDynamin (Dyn) is an ϳ100-kDa multidomain GTPase that was first identified as a microtubule binding and bundling protein (Shpetner and Vallee, 1989). Subsequently, dynamin was found to be the mammalian homologue of the Drosophila protein shibire, mutations in which block endocytosis, including synaptic vesicle recycling (Chen et al., 1991;van der Bliek and Meyerowitz, 1991). Dynamin is conserved throughout higher eukaryotes. There is a single gene in Drosophila and Caenorhabditis elegans, but there are three dynamin isoforms in mammals: Dyn1, which is specifically expressed in neurons; Dyn2, which is ubiquitously expressed; and Dyn3, which is mainly expressed in the brain and testes (Urrutia et al., 1997, Ferguson et al., 2007.The best-studied cellular function of dynamin is its involvement in clathrin-mediated endocytosis (CME; Hinshaw, 2000;Sever et al., 2000;Praefcke and McMahon, 2004). However, dynamin has also been implicated in several other membrane-trafficking events including both caveolae-mediated and clathrin-and caveolin-independent endocytic pathways Oh et al., 1998;Lamaze et al., 2001;Pelkmans et al., 2002), phagocytosis (Gold et al., 1999;Yu et al., 2006), macropinocytosis (Schlunck et al., 2004), and trafficking from the trans-Golgi network (TGN; Jones et al., 1998;Kreitzer et al., 2000;Bonazzi et al., 2005). Because these functions have mostly emerged from studying the effects of overexpression of dominant-negative dynamin mutants, they may reflect indirect or nonspecific effects. Moreover, it is not known whether different dynamin isoforms and/or splice varia...

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Section: Dyn2mentioning

confidence: 77%

“…The TGN-exit assay of p75-mRFP (from E. Rodriguez-Boulan, Weill Medical College of Cornell University, New York, NY) was performed as described (Bonazzi et al, 2005) with some modification. Briefly, the cells transfected with p75-monermeric red fluorescent protein (mRFP) were incubated overnight in complete medium.…”

Section: P75 Tgn Export Assaymentioning

confidence: 99%

Isoform and Splice-Variant Specific Functions of Dynamin-2 Revealed by Analysis of Conditional Knock-Out Cells

Liu

Surka

Schroeter

et al. 2008

MBoC

125

163

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“…This would result in PA with more negative curvature in the Golgi luminal leaflet than in the cytoplasmic leaflet. If PA formed in the cytoplasmic leaflet would be able to translocate (49) to the luminal site, it might facilitate the fission of the budding transport carrier by CtBP3/BARS (11,50,51). Thus, a defined charge of (L)PA at a particular (intra)cellular location, determined largely by the local PC:PE ratio, may be a key element of the action of (L)PA at that specific location, and regulate protein recruitment, activation, etc.…”

Section: Discussionmentioning

confidence: 99%

What Makes the Bioactive Lipids Phosphatidic Acid and Lysophosphatidic Acid So Special?

et al. 2005

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Phosphatidic acid and lysophosphatidic acid are minor but important anionic bioactive lipids involved in a number of key cellular processes, yet these molecules have a simple phosphate headgroup.To find out what is so special about these lipids, we determined the ionization behavior of phosphatidic acid (PA) and lysophosphatidic acid (LPA) in extended (flat) mixed lipid bilayers using magic angle spinning 31 P NMR. Our data show two surprising results. First, despite identical phosphomonoester headgroups, LPA carries more negative charge than PA when present in a phosphatidylcholine bilayer. Dehydroxy-LPA [1-oleoyl-3-(phosphoryl)propanediol] behaves in a manner identical to that of PA, indicating that the difference in negative charge between LPA and PA is caused by the hydroxyl on the glycerol backbone of LPA and its interaction with the phosphomonoester headgroup. Second, deprotonation of phosphatidic acid and lysophosphatidic acid was found to be strongly stimulated by the inclusion of phosphatidylethanolamine in the bilayer, indicating that lipid headgroup charge depends on local lipid composition and will vary between the different subcellular locations of (L)PA. Our findings can be understood in terms of a hydrogen bond formed within the phosphomonoester headgroup of (L)PA and its destabilization by competing intra-or intermolecular hydrogen bonds. We propose that this hydrogen bonding property of (L)PA is involved in the various cellular functions of these lipids.Phosphatidic acid (PA) 1 and the related lipid lysophosphatidic acid (LPA) are important minor lipid species in the cell. They are involved in many intracellular processes, and are important intermediates in lipid biosynthesis (1). For example, binding of LPA to its receptors evokes various cellular responses, and the local formation of (L)PA is part of signaling cascades, in particular in the regulation of membrane dynamics such as fusion and fission events, either indirectly through the recruitment of downstream effectors or directly by mediating (local) changes in the biophysical properties of the membrane (2-12).PA and LPA have a relatively simple chemical structure consisting of only a glycerol, one (LPA) or two (PA) acyl chains, and a phosphate, and it is interesting to note that these simple phospholipids are involved in such diverse processes, and are able to bind specifically to so many different types of proteins (3, 13). The question then is what is so special about these lipids. An obvious suggestion relates to the phosphate headgroup, which is attached to the glycerol backbone as a phosphomonoester, a unique feature of these lipids. Phosphomonoesters have two pK a 's, one of which is expected to be in the physiological pH range. As a consequence, small changes in (physiological) pH will affect the charge and influence the molecular shape and lipid phase behavior of these lipids (14,15). Under physiological conditions at neutral pH, phosphatidic acid is a cone (type II)-shaped lipid with a negative spontaneous curvature clos...

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“…Apical endocytosis requires polymerized actin, whereas basolateral endocytosis does not (Gottlieb et al, 1993). The exit of apical proteins from TGN/RE requires the actinand MT-associated protein dynamin 2 (Kreitzer et al, 2000;Bonazzi et al, 2005), whereas basolateral proteins require different proteins, such as BARS (Kreitzer et al, 2000;Bonazzi et al, 2005) and protein kinase D (Yeaman et al, 2004a).…”

Section: Polarized Trafficking Machinerymentioning

confidence: 99%

The epithelial polarity program: machineries involved and their hijacking by cancer

2008

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The Epithelial Polarity Program (EPP) adapts and integrates three ancient cellular machineries to construct an epithelial cell. The polarized trafficking machinery adapts the cytoskeleton and ancestral secretory and endocytic machineries to the task of sorting and delivering different plasma membrane (PM) proteins to apical and basolateral surface domains. The domain-identity machinery builds a tight junctional fence (TJ) between apical and basolateral PM domains and adapts ancient polarity proteins and polarity lipids on the cytoplasmic side of the PM, which have evolved to perform a diversity of polarity tasks across cells and species, to provide 'identity' to each epithelial PM domain. The 3D organization machinery utilizes adhesion molecules as positional sensors of other epithelial cells and the basement membrane and small GTPases as integrators of positional information with the activities of the domain-identity and polarized trafficking machineries. Cancer is a disease mainly of epithelial cells (90% of human cancers are carcinomas that derive from epithelial cells) that hijacks the EPP machineries, resulting in loss of epithelial polarity, which often correlates in extent with the aggressiveness of the tumor. Here, we review how the EPP integrates its three machineries and the strategies used by cancer to hijack them.

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CtBP3/BARS drives membrane fission in dynamin-independent transport pathways

Cited by 158 publications

References 48 publications

Isoform and Splice-Variant Specific Functions of Dynamin-2 Revealed by Analysis of Conditional Knock-Out Cells

Isoform and Splice-Variant Specific Functions of Dynamin-2 Revealed by Analysis of Conditional Knock-Out Cells

What Makes the Bioactive Lipids Phosphatidic Acid and Lysophosphatidic Acid So Special?

The epithelial polarity program: machineries involved and their hijacking by cancer

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