Hrs and SNX3 Functions in Sorting and Membrane Invagination within Multivesicular Bodies

Pons, Véronique; Luyet, Pierre‐Philippe; Morel, Étienne; Abrami, Laurence; Goot, F. Gisou van der; Parton, Robert G.; Grüenberg, Jean

doi:10.1371/journal.pbio.0060214

Cited by 93 publications

(117 citation statements)

References 61 publications

(133 reference statements)

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“…In contrast, we find that Hrs is not involved in the process. However, the functions of Hrs in lumenal vesicle formation (Lloyd et al, 2002;Bache et al, 2003b;Razi and Futter, 2006) are not clear and may well be indirect (Pons et al, 2008). Although Alix negatively regulates the formation of lumenal vesicles and EGF receptor sorting, our data show that Tsg101 is a necessary component of the budding reaction.…”

Section: Discussionmentioning

confidence: 74%

“…The pH was calculated from the fluorescence ratio measured in each case after excitation at 445 and 397 nm. Hrs knockdown ( Figure 6D, inset) had little, if any, effect on intralumenal vesicle formation in late ( Figure 6D) or early (Supplemental Figure S6D) endosomes, but it is not clear whether Hrs is directly involved in the formation of intralumenal vesicles (Gruenberg and Stenmark, 2004;Pons et al, 2008). We then used the dominant negative mutant K173Q of the triple A ATPase Vps4 (Morita et al, 2007a), which releases ESCRT-III from membranes (Hurley and Emr, 2006), to further investigate the role of ESCRTs in our assay.…”

Section: Role Of the Escrt-i Subunit Tsg101 In Intralumenal Vesicle Fmentioning

confidence: 99%

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In Vitro Budding of Intralumenal Vesicles into Late Endosomes Is Regulated by Alix and Tsg101

Falguières

Luyet

Bissig

et al. 2008

MBoC

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Endosomes along the degradation pathway leading to lysosomes accumulate membranes in their lumen and thus exhibit a characteristic multivesicular appearance. These lumenal membranes typically incorporate down-regulated EGF receptor destined for degradation, but the mechanisms that control their formation remain poorly characterized. Here, we describe a novel quantitative biochemical assay that reconstitutes the formation of lumenal vesicles within late endosomes in vitro. Vesicle budding into the endosome lumen was time-, temperature-, pH-, and energy-dependent and required cytosolic factors and endosome membrane components. Our light and electron microscopy analysis showed that the compartment supporting the budding process was accessible to endocytosed bulk tracers and EGF receptor. We also found that the EGF receptor became protected against trypsin in our assay, indicating that it was sorted into the intraendosomal vesicles that were formed in vitro. Our data show that the formation of intralumenal vesicles is ESCRT-dependent, because the process was inhibited by the K173Q dominant negative mutant of hVps4. Moreover, we find that the ESCRT-I subunit Tsg101 and its partner Alix control intralumenal vesicle formation, by acting as positive and negative regulators, respectively. We conclude that budding of the limiting membrane toward the late endosome lumen, which leads to the formation of intraendosomal vesicles, is controlled by the positive and negative functions of Tsg101 and Alix, respectively. INTRODUCTIONIn eukaryotic cells, molecules of the plasma membrane, ligands and solutes are internalized into early endosomes, from where they can be recycled back to the plasma membrane, transported to the trans-Golgi network, or targeted to late endosomes and lysosomes (Gruenberg, 2001;Maxfield and McGraw, 2004;Mayor and Pagano, 2007). The latter pathway is followed in particular by ubiquitinated signaling receptors that need to be down-regulated. These receptors are incorporated into invaginations of the early endosomal membrane that form within their lumen (Hurley and Emr, 2006), thus giving rise to nascent multivesicular bodies (MVBs) or endosomal carrier vesicles (ECVs; Gruenberg and Stenmark, 2004;Piper and Katzmann, 2007), which function as intermediates between early and late endosomes. Eventually, intralumenal vesicles are delivered to lysosomes, where they are degraded together with their receptor cargo.Major progress has been made in our understanding of the molecular mechanisms that control the sorting of ubiquitinated receptors, in particular the epidermal growth factor (EGF) receptor (Hurley and Emr, 2006;Slagsvold et al., 2006;Piper and Katzmann, 2007;Williams and Urbe, 2007). These receptors interact via the ubiquitin moiety with hepatocyte growth factor-regulated tyrosine kinase substrate (Hrs), which in turn binds clathrin and phosphatidyl-inositol-3-phosphate (PtdIns3P), thereby concentrating the receptor in early endosomal membrane domains (Raiborg et al., 2001;Urbe et al., 2003;Raiborg et al., ...

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Section: Discussionmentioning

confidence: 74%

Section: Role Of the Escrt-i Subunit Tsg101 In Intralumenal Vesicle Fmentioning

confidence: 99%

In Vitro Budding of Intralumenal Vesicles into Late Endosomes Is Regulated by Alix and Tsg101

Falguières

Luyet

Bissig

et al. 2008

MBoC

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“…There, cargo can be sorted to different cellular destinations, including the plasma membrane, the trans-Golgi network (TGN), or late endosomes. Early endosomes contain tubular and cisternal elements, as well as vacuolar regions, where intralumenal vesicles (ILVs) of well-defined size, with a diameter of 50 and 30 nm in mammalian and yeast cells, respectively (Mari et al 2008;Pons et al 2008;Wemmer et al 2011), are formed by budding of the limiting membrane away from the cytosol toward the endosome lumen ( Fig. 1) (Gruenberg 2001;Huotari and Helenius 2011).…”

Section: Organization Of the Endosomal Pathwaymentioning

confidence: 99%

“…Many proteins involved in the regulation of endosomal dynamics contain phospholipid-bind- Simonsen et al 1998;McBride et al 1999;Pankiv et al 2010;c Carlton et al 2004;Bonifacino and Hurley 2008;d Pons et al 2008;Harterink et al 2011;Chen et al 2013;e Lloyd et al 2002;Bache et al 2003;Pons et al 2008; f Simonsen et al 2004;Filimonenko et al 2010; g Sbrissa et al 2002a;h Cabezas et al 2006;Ikonomov et al 2006;Rutherford et al 2006; see Tooze and Elazar 2013; and references in Mayinger 2012; j Ramel et al 2011;Zolov et al 2012;Oppelt et al 2013;k Gagescu et al 2000;Leventis and Grinstein 2010;Fairn et al 2011;l Uchida et al 2011;m Mobius et al 2003;Ikonen 2008;Maxfield and van Meer 2010;n Vanier and Millat 2003;Ohgami et al 2004;Xu et al 2007;Kwon et al 2009; o Kobayashi et al 1999Kobayashi et al , 2002p Matsuo et al 2004;Kirkegaard et al 2010;Bissig et al 2013. ing domains (Fig. 3B).…”

Section: Lipids As Organizing Principles Of Peripheral Membrane Proteinsmentioning

confidence: 99%

Lipid Sorting and Multivesicular Endosome Biogenesis

Bissig

Grüenberg

2013

Cold Spring Harbor Perspectives in Biology

133

107

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Intracellular organelles, including endosomes, show differences not only in protein but also in lipid composition. It is becoming clear from the work of many laboratories that the mechanisms necessary to achieve such lipid segregation can operate at very different levels, including the membrane biophysical properties, the interactions with other lipids and proteins, and the turnover rates or distribution of metabolic enzymes. In turn, lipids can directly influence the organelle membrane properties by changing biophysical parameters and by recruiting partner effector proteins involved in protein sorting and membrane dynamics. In this review, we will discuss how lipids are sorted in endosomal membranes and how they impact on endosome functions.

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“…SNX1 and SNX2 are essential for sorting and trafficking of transmembrane cargoes from endosomes to the trans-Golgi network (TGN) [15]. SNX3 binds to PI(3)P [16] and is required for biogenesis of endocytic carrier vesicles/multivesicular bodies [17]. SNX4 associates with dynein/dynactin through its interaction with the dynein light chain 1-binding protein KIBRA and is required for transport of the transferrin receptor between peripheral early endosomes and the juxtanuclear endocytic recycling compartment [18].…”

Section: Introductionmentioning

confidence: 99%

The retromer component SNX6 interacts with dynactin p150Glued and mediates endosome-to-TGN transport

et al. 2009

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The retromer is a protein complex that mediates retrograde transport of transmembrane cargoes from endosomes to the trans-Golgi network (TGN). It is comprised of a cargo-selection subcomplex of Vps26, Vps29 and Vps35 and a membrane-binding coat subcomplex of sorting nexins (SNXs). Previous studies identified SNX1/2 as one of the components of the SNX subcomplex, and SNX5/6 as candidates for the second SNX. How the retromer-associated cargoes are recognized and transported by molecular motors are largely unknown. In this study, we found that one of SNX1/2's dimerization partners, SNX6, interacts with the p150 Glued subunit of the dynein/dynactin motor complex. We present evidence that SNX6 is a component of the retromer, and that recruitment of the motor complex to the membrane-associated retromer requires the SNX6-p150 Glued interaction. Disruption of the SNX6-p150 Glued interaction causes failure in formation and detachment of the tubulovesicular sorting structures from endosomes and results in block of CI-MPR retrieval from endosomes to the TGN. These observations indicate that in addition to SNX1/2, SNX6 in association with the dynein/dynactin complex drives the formation and movement of tubular retrograde intermediates.

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Hrs and SNX3 Functions in Sorting and Membrane Invagination within Multivesicular Bodies

Cited by 93 publications

References 61 publications

In Vitro Budding of Intralumenal Vesicles into Late Endosomes Is Regulated by Alix and Tsg101

In Vitro Budding of Intralumenal Vesicles into Late Endosomes Is Regulated by Alix and Tsg101

Lipid Sorting and Multivesicular Endosome Biogenesis

The retromer component SNX6 interacts with dynactin p150Glued and mediates endosome-to-TGN transport

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