scholarly journals Regulated compartmentalization of enzymes in Golgi by GRASP55 controls cellular glycosphingolipid profile and function

2020 ◽  
Author(s):  
Prathyush Pothukuchi ◽  
Ilenia Agliarulo ◽  
Marinella Pirozzi ◽  
Riccardo Rizzo ◽  
Domenico Russo ◽  
...  
Keyword(s):  
Cell Growth ◽  
Golgi Apparatus ◽  
Cell Density ◽  
Matrix Protein ◽  
Biosynthetic Enzymes ◽  
Density Dependent ◽  
Golgi Vesicles ◽  
And Function ◽  
Golgi Matrix ◽  
Glycosphingolipid Biosynthesis

AbstractGlycans are important regulators of cell and organismal physiology. This requires that the glycan biosynthesis be controlled to achieve specific cellular glycan profiles. Glycans are assembled in the Golgi apparatus on secretory cargoes that traverse it. The mechanisms by which the Golgi apparatus ensures cell- and cargo-specific glycosylation remain obscure. We investigated how the Golgi apparatus regulates glycosylation by studying biosynthesis of glycosphingolipids, glycosylated lipids with critical roles in signalling and differentiation. We identified the Golgi matrix protein GRASP55 as a controller of sphingolipid glycosylation by regulating the compartmentalized localization of key sphingolipid biosynthetic enzymes in the Golgi. GRASP55 controls the localization of the enzymes by binding to them and regulating their entry into peri-Golgi vesicles. Impairing GRASP55-enzyme interaction decompartmentalizes these enzymes, changes the substrate flux across competing glycosylation pathways that results in alteration of the cellular glycosphingolipid profile. This GRASP55 regulated pathway of enzyme compartmentalization allows cells to make cell density-dependent adaptations in glycosphingolipid biosynthesis to suit cell growth needs. Thus, the Golgi apparatus controls the cellular glycan (glycosphingolipid) profile by governing competition between biosynthetic reactions through regulated changes in enzyme compartmentalization.

scholarly journals A GRASP55-rab2 effector complex linking Golgi structure to membrane traffic

2001 ◽  
Vol 155 (6) ◽  
pp. 877-884 ◽  
Author(s):  
Benjamin Short ◽  
Christian Preisinger ◽  
Roman Körner ◽  
Robert Kopajtich ◽  
Olwyn Byron ◽  
...  
Keyword(s):  
Golgi Apparatus ◽  
Matrix Protein ◽  
Protein Transport ◽  
Coiled Coil ◽  
Membrane Traffic ◽  
Secretory Protein ◽  
Rab Gtpase ◽  
Rab Proteins ◽  
Golgi Structure ◽  
Golgi Matrix

Membrane traffic between the endoplasmic reticulum (ER) and Golgi apparatus and through the Golgi apparatus is a highly regulated process controlled by members of the rab GTPase family. The GTP form of rab1 regulates ER to Golgi transport by interaction with the vesicle tethering factor p115 and the cis-Golgi matrix protein GM130, also part of a complex with GRASP65 important for the organization of cis-Golgi cisternae. Here, we find that a novel coiled-coil protein golgin-45 interacts with the medial-Golgi matrix protein GRASP55 and the GTP form of rab2 but not other Golgi rab proteins. Depletion of golgin-45 disrupts the Golgi apparatus and causes a block in secretory protein transport. These results demonstrate that GRASP55 and golgin-45 form a rab2 effector complex on medial-Golgi essential for normal protein transport and Golgi structure.

scholarly journals EspG of enteropathogenic and enterohemorrhagic E. coli binds the Golgi matrix protein GM130 and disrupts the Golgi structure and function

2011 ◽  
Vol 13 (9) ◽  
pp. 1429-1439 ◽  
Author(s):  
Abigail Clements ◽  
Katherine Smollett ◽  
Sau Fung Lee ◽  
Elizabeth L. Hartland ◽  
Martin Lowe ◽  
...  
Keyword(s):  
Matrix Protein ◽  
Structure And Function ◽  
E Coli ◽  
Golgi Structure ◽  
And Function ◽  
Golgi Matrix

scholarly journals GS15 Forms a SNARE Complex with Syntaxin 5, GS28, and Ykt6 and Is Implicated in Traffic in the Early Cisternae of the Golgi Apparatus

2002 ◽  
Vol 13 (10) ◽  
pp. 3493-3507 ◽  
Author(s):  
Yue Xu ◽  
Sally Martin ◽  
David E. James ◽  
Wanjin Hong
Keyword(s):  
Golgi Apparatus ◽  
Brefeldin A ◽  
Snare Complex ◽  
Er Exit Sites ◽  
And Function ◽  
Mutant Forms ◽  
Interfering Rna ◽  
Kdel Receptor ◽  
Golgi Matrix

The subcellular localization, interacting partners, and function of GS15, a Golgi SNARE, remain to be established. In our present study, it is revealed that unlike proteins (Bet1 and the KDEL receptor) cycling between the Golgi and the intermediate compartment (IC, inclusive of the ER exit sites), GS15 is not redistributed into the IC upon incubation at 15°C or when cells are treated with brefeldin A. Immuno-electron microscopy (immuno-EM) reveals that GS15 is mainly found in the medial-cisternae of the Golgi apparatus and adjacent tubulo-vesicular elements. Coimmunoprecipitation experiments suggest that GS15 exists in a distinct SNARE complex that contains SNAREs (syntaxin5, GS28, and Ykt6) that are implicated in both ER-to-Golgi and intra-Golgi transport but not with SNAREs involved exclusively in ER-to-Golgi traffic. Furthermore, components of COPI coat can be selectively coimmunoprecipitated with GS15 from Golgi extracts. Overexpression of mutant forms of GS15 affects the normal distribution of cis- and medial-Golgi proteins (GS28, syntaxin 5, and Golgi mannosidase II), whereas proteins of the trans-Golgi and TGN (Vti1-rp2/Vti1a and syntaxin 6) and Golgi matrix/scaffold (GM130 and p115) are less affected. When the level of GS15 is reduced by duplex 21-nt small interfering RNA (siRNA)-mediated knockdown approach, diverse markers of the Golgi apparatus are redistributed into small dotty and diffuse labeling, suggesting an essential role of GS15 in the Golgi apparatus.

scholarly journals YSK1 is activated by the Golgi matrix protein GM130 and plays a role in cell migration through its substrate 14-3-3ζ

2004 ◽  
Vol 164 (7) ◽  
pp. 1009-1020 ◽  
Author(s):  
Christian Preisinger ◽  
Benjamin Short ◽  
Veerle De Corte ◽  
Erik Bruyneel ◽  
Alexander Haas ◽  
...  
Keyword(s):  
Cell Migration ◽  
Golgi Apparatus ◽  
Matrix Protein ◽  
Protein Transport ◽  
Type I Collagen ◽  
Migration And Invasion ◽  
Specific Substrate ◽  
Type I ◽  
Signaling Events ◽  
Golgi Matrix

The Golgi apparatus has long been suggested to be important for directing secretion to specific sites on the plasma membrane in response to extracellular signaling events. However, the mechanisms by which signaling events are coordinated with Golgi apparatus function remain poorly understood. Here, we identify a scaffolding function for the Golgi matrix protein GM130 that sheds light on how such signaling events may be regulated. We show that the mammalian Ste20 kinases YSK1 and MST4 target to the Golgi apparatus via the Golgi matrix protein GM130. In addition, GM130 binding activates these kinases by promoting autophosphorylation of a conserved threonine within the T-loop. Interference with YSK1 function perturbs perinuclear Golgi organization, cell migration, and invasion into type I collagen. A biochemical screen identifies 14-3-3ζ as a specific substrate for YSK1 that localizes to the Golgi apparatus, and potentially links YSK1 signaling at the Golgi apparatus with protein transport events, cell adhesion, and polarity complexes important for cell migration.

Golgi Apparatus and Melanogenesis: Ultrastructural Study of a Human Cellular Blue Nevus (Melanocytoma)

1973 ◽  
Vol 31 ◽  
pp. 380-381
Author(s):  
S.R. Allegra
Keyword(s):  
Endoplasmic Reticulum ◽  
Golgi Apparatus ◽  
Ultrastructural Study ◽  
The Other ◽  
Blue Nevus ◽  
Normal Complement ◽  
Golgi Vesicles ◽  
Golgi System ◽  
The Subject ◽  
Cellular Blue Nevus

The respective roles of the ribo somes, endoplasmic reticulum, Golgi apparatus and perhaps nucleus in the synthesis and maturation of melanosomes is still the subject of some controversy. While the early melanosomes (premelanosomes) have been frequently demonstrated to originate as Golgi vesicles, it is undeniable that these structures can be formed in cells in which Golgi system is not found. This report was prompted by the findings in an essentially amelanotic human cellular blue nevus (melanocytoma) of two distinct lines of melanocytes one of which was devoid of any trace of Golgi apparatus while the other had normal complement of this organelle.

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