title: Sorting nexin 10 induces giant vacuoles in mammalian cells.
abstract: Eukaryotic cells maintain a sophisticated network of intracellular membranous system to ensure the proper distribution and compartmentalization of cellular proteins critical for diverse functions such as cell division or cell-cell communication. Yet, little is known about the mechanism that regulates the homeostasis of this system. While analyzing the impact of sorting nexins on the trafficking of membrane type matrix metalloproteinases, we unexpectedly discovered that the expression of SNX10 induced the formation of giant vacuoles in mammalian cells. This vacuolizing activity is sensitive to mutations at the putative phosphoinositide 3-phosphate binding residue Arg(53). Domain-swap experiments with SNX3 demonstrate that the PX domain of SNX10 alone is insufficient to generate vacuoles and the downstream C-terminal domain is required for vacuolization. Brefeldin A, a chemical known to block the endoplasmic reticulum to Golgi transport, inhibited the vacuolization process. Together, these results suggest that SNX10 activity may be involved in the regulation of endosome homeostasis.
authors.affiliation: Guangzhou Institute of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou 510663, China.
authors.forename: Baoming
authors.initials: B
authors.lastname: Qin
authors.forename: Miao
authors.initials: M
authors.lastname: He
authors.forename: Xiao
authors.initials: X
authors.lastname: Chen
authors.forename: Duanqing
authors.initials: D
authors.lastname: Pei
mesh_terms: D001120:Arginine / Q000737:chemistry; D020126:Brefeldin A / Q000737:chemistry; D002352:Carrier Proteins / Q000737:chemistry* / Q000502:physiology*; D002450:Cell Communication; D018076:DNA, Complementary / Q000378:metabolism; D004721:Endoplasmic Reticulum / Q000378:metabolism; D011992:Endosomes / Q000378:metabolism; D006056:Golgi Apparatus / Q000378:metabolism; D006367:HeLa Cells; D006706:Homeostasis; D006801:Humans; D010716:Phosphatidylinositols / Q000737:chemistry; D017434:Protein Structure, Tertiary; D058305:Sorting Nexins; D013997:Time Factors; D014617:Vacuoles / Q000378:metabolism; D033921:Vesicular Transport Proteins / Q000737:chemistry* / Q000502:physiology*
chemical_list: D002352:Carrier Proteins; D018076:DNA, Complementary; D010716:Phosphatidylinositols; C516568:SNX10 protein, human; D058305:Sorting Nexins; D033921:Vesicular Transport Proteins; C483312:phosphoinositide 3-phosphate; D020126:Brefeldin A; D001120:Arginine