| 1. |
- Baietti, Maria Francesca, et al.
(författare)
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Syndecan-syntenin-ALIX regulates the biogenesis of exosomes
- 2012
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Ingår i: Nature cell biology. - : Springer Science and Business Media LLC. - 1476-4679 .- 1465-7392. ; 14:7, s. 677-685
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Tidskriftsartikel (refereegranskat)abstract
- The biogenesis of exosomes, small secreted vesicles involved in signalling processes, remains incompletely understood. Here, we report evidence that the syndecan heparan sulphate proteoglycans and their cytoplasmic adaptor syntenin control the formation of exosomes. Syntenin interacts directly with ALIX through LYPX(n)L motifs, similarly to retroviral proteins, and supports the intraluminal budding of endosomal membranes. Syntenin exosomes depend on the availability of heparan sulphate, syndecans, ALIX and ESCRTs, and impact on the trafficking and confinement of FGF signals. This study identifies a key role for syndecan-syntenin-ALIX in membrane transport and signalling processes.
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| 2. |
- Lambaerts, Kathleen, et al.
(författare)
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Syntenin, a syndecan adaptor and an Arf6 phosphatidylinositol 4,5-bisphosphate effector, is essential for epiboly and gastrulation cell movements in zebrafish
- 2012
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Ingår i: Journal of Cell Science. - : The Company of Biologists. - 0021-9533 .- 1477-9137. ; 125:Pt 5, s. 1129-1140
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Tidskriftsartikel (refereegranskat)abstract
- Epiboly, the spreading and the thinning of the blastoderm to cover the yolk cell and close the blastopore in fish embryos, is central to the process of gastrulation. Despite its fundamental importance, little is known about the molecular mechanisms that control this coordinated cell movement. By a combination of knockdown studies and rescue experiments in zebrafish (Danio rerio), we show that epiboly relies on the molecular networking of syntenin with syndecan heparan sulphate proteoglycans, which act as co-receptors for adhesion molecules and growth factors. Furthermore, we show that the interaction of syntenin with phosphatidylinositol 4,5-bisphosphate (PIP2) and with the small GTPase ADP-ribosylation factor 6 (Arf6), which regulate the endocytic recycling of syndecan, is necessary for epiboly progression. Analysis of the earliest cellular defects suggests a role for syntenin in the autonomous vegetal expansion of the yolk syncytial layer and the rearrangement of the actin cytoskeleton in extra-embryonic tissues, but not in embryonic cell fate determination. This study identifies the importance of the syntenin-syndecan-PIP2-Arf6 complex for the progression of fish epiboly and establishes its key role in directional cell movements during early development.
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| 3. |
- Wawrzyniak, Anna Maria, et al.
(författare)
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Extensions of PSD-95/discs large/ZO-1 (PDZ) domains influence lipid binding and membrane targeting of syntenin-1
- 2012
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Ingår i: FEBS Letters. - : Wiley. - 0014-5793 .- 1873-3468. ; 586:10, s. 1445-1451
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Tidskriftsartikel (refereegranskat)abstract
- Syntenin-1 is a PDZ protein involved in receptor recycling and clustering. Its two PDZ domains interact with various receptors and phosphoinositides, and are flanked by N- and C-terminal regions. Here, we report the identification of an autoinhibitory peptide stretch in the N-terminus that might be regulated by phosphorylation. We further establish that basic residues in the C-terminal region mediate electrostatic interactions with reconstituted liposomes and contribute to the plasma membrane targeting. Our study adds new components to the multi-dentate membrane targeting mechanism and highlights the role of N- and C-terminal PDZ extensions in the regulation of syntenin-1 plasma membrane localization.
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