Formation of multivesicular endosomes in <i>Dictyostelium</i>

Marchetti, Anna; Mercanti, Valentina; Cornillon, Sophie; Alibaud, Laethitia; Charette, Steve J.; Cosson, Pierre

doi:10.1242/jcs.01524

Cited by 30 publications

(34 citation statements)

References 30 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…2A The size and number of lysosomes was also determined in random confocal pictures of cells stained for both H + -ATPase and p80. The diameter of lysosomes in lvsB mutant cells was 27% larger than in WT cells (see Table 1), corroborating previous observations (Harris et al, 2002;Marchetti et al, 2004), but their number was reduced by 28%. Overall the total surface of lysosomal compartments was 23% higher in lvsB than in WT cells (Table 1).…”

Section: Decreased Number Of Post Lysosomes In Lvsb Mutant Cellssupporting

confidence: 90%

“…of the LYST gene recapitulate several features of the ChediakHigashi syndrome in Dictyostelium cells , notably an enlargement of endocytic compartments, and anomalies in the secretion of lysosomal enzymes (Cornillon et al, 2002;Harris et al, 2002;Marchetti et al, 2004). Here we show that the Dictyostelium LvsB protein is specifically involved in the biogenesis of fusion-competent post-lysosomal compartments.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

A LYST/beige homolog is involved in biogenesis ofDictyosteliumsecretory lysosomes

Charette

Cosson

2007

Journal of Cell Science

Self Cite

View full text Add to dashboard Cite

Chediak-Higashi syndrome (CHS) is characterized at the cellular level by a defect in the ability of cells to secrete lysosomes. However, the precise step affected in the secretion process is unclear. We characterized Dictyostelium discoideum cells containing a mutation in lvsB, the homolog of the human gene (LYST) involved in CHS. As observed in mammalian cells, secretion of lysosome-derived compartments was affected in lvsB mutant cells. This defect was mirrored by a decrease in the number of fusion-competent post-lysosomal compartments, which in Dictyostelium can be clearly distinguished from lysosomes. In addition, the transfer of endocytosed particles from lysosomes to post lysosomes was strongly diminished in lvsB mutant cells compared with the wild type. These results suggest that LvsB is primarily involved in transport from lysosomes to post lysosomes, and thus plays a critical role in the maturation of lysosomes into fusion-competent post-lysosomal compartments

show abstract

Section: Decreased Number Of Post Lysosomes In Lvsb Mutant Cellssupporting

confidence: 90%

Section: Introductionmentioning

confidence: 99%

A LYST/beige homolog is involved in biogenesis ofDictyosteliumsecretory lysosomes

Charette

Cosson

2007

Journal of Cell Science

Self Cite

View full text Add to dashboard Cite

show abstract

“…Cholesterol concentration may also facilitate the budding process either by promoting proper membrane curvature (Wang et al 2007) or by organizing discrete sudomains enriched in proteins such as tetraspanins (Charrin et al 2003, Silvie et al 2006, which are incorporated into ILVs (Escola et al 1998). Interestingly, inducing accumulation of cholesterol within endosomes with the drug U18666A dramatically stimulates inward budding of endosomes and the formation of MVBs in Dictyostelium (Marchetti et al 2004). Also, two members of the oxysterol-binding-protein family, Osh6 and Osh7, associate with Vps4, an AAA-ATPase that controls the assembly of the MVB protein sorting machinery (Wang et al 2005).…”

Section: Machinery Lipid Sortingmentioning

confidence: 99%

“…Furthermore, Hrs interacts with a variety of proteins that participate in a host of other endosomal processes (Chin et al 2001, Rayala et al 2006, Sun et al 2003, Yan et al 2005. Finally, the Hrs/STAM complex is not encoded in plant and Dictyostelium genomes, although those organisms do have ESCRT-I, II, and III homologs (Marchetti et al 2004, Winter & Hauser 2006. The Hrs-STAM complex works in parallel with GGA proteins as well as the Tom1-Tollip complex to bind, retain, and concentrate Ub-cargo on endosomal subdomains (Raiborg et al 2002).…”

Section: Protein Machinerymentioning

confidence: 99%

Biogenesis and Function of Multivesicular Bodies

Piper

Katzmann

2007

Annu. Rev. Cell Dev. Biol.

662

660

View full text Add to dashboard Cite

The two major cellular sites for membrane protein degradation are the proteasome and the lysosome. Ubiquitin attachment is a sorting signal for both degradation routes. For lysosomal degradation, ubiquitination triggers the sorting of cargo proteins into the lumen of late endosomal multivesicular bodies (MVBs)/endosomes. MVB formation occurs when a portion of the limiting membrane of an endosome invaginates and buds into its own lumen. Intralumenal vesicles are degraded when MVBs fuse to lysosomes. The proper delivery of proteins to the MVB interior relies on specific ubiquitination of cargo, recognition and sorting of ubiquitinated cargo to endosomal subdomains, and the formation and scission of cargo-filled intralumenal vesicles. Over the past five years, a number of proteins that may directly participate in these aspects of MVB function and biogenesis have been identified. However, major questions remain as to exactly what these proteins do at the molecular level and how they may accomplish these tasks.

show abstract

“…MLBs are not produced only by higher eukaryotic cells, as they have also been observed in protozoa and, more particularly, in Dictyostelium discoideum (2)(3)(4)(5)(6)(7)(8)(9)(10). D. discoideum is a soil amoeba and a bacterial predator that internalizes its prey through phagocytosis.…”

mentioning

confidence: 99%

Lipid Composition of Multilamellar Bodies Secreted by Dictyostelium discoideum Reveals Their Amoebal Origin

et al. 2013

Self Cite

View full text Add to dashboard Cite

When they are fed with bacteria, Dictyostelium discoideum amoebae produce and secrete multilamellar bodies (MLBs), which are composed of membranous material. It has been proposed that MLBs are a waste disposal system that allows D. discoideum to eliminate undigested bacterial remains. However, the real function of MLBs remains unknown. Determination of the biochemical composition of MLBs, especially lipids, represents a way to gain information about the role of these structures. To allow these analyses, a protocol involving various centrifugation procedures has been developed to purify secreted MLBs from amoeba-bacterium cocultures. The purity of the MLB preparation was confirmed by transmission electron microscopy and by immunofluorescence using H36, an antibody that binds to MLBs. The lipid and fatty acid compositions of pure MLBs were then analyzed by high-performance thin-layer chromatography (HPTLC) and gas chromatography (GC), respectively, and compared to those of amoebae as well as bacteria used as a food source. While the bacteria were devoid of phosphatidylcholine (PC) and phosphatidylinositol (PI), these two polar lipid species were major classes of lipids in MLBs and amoebae. Similarly, the fatty acid composition of MLBs and amoebae was characterized by the presence of polyunsaturated fatty acids, while cyclic fatty acids were found only in bacteria. These results strongly suggest that the lipids constituting the MLBs originate from the amoebal metabolism rather than from undigested bacterial membranes. This opens the possibility that MLBs, instead of being a waste disposal system, have unsuspected roles in D. discoideum physiology.

show abstract

Formation of multivesicular endosomes in Dictyostelium

Cited by 30 publications

References 30 publications

A LYST/beige homolog is involved in biogenesis ofDictyosteliumsecretory lysosomes

A LYST/beige homolog is involved in biogenesis ofDictyosteliumsecretory lysosomes

Biogenesis and Function of Multivesicular Bodies

Lipid Composition of Multilamellar Bodies Secreted by Dictyostelium discoideum Reveals Their Amoebal Origin

Contact Info

Product

Resources

About