scholarly journals GRASPing for consensus about the Golgi apparatus

2021 ◽  
Vol 220 (5) ◽  
Author(s):  
Christopher G. Burd
Keyword(s):  
Golgi Apparatus ◽  
Golgi Ribbon

Cisternae of the Golgi apparatus adhere to each other to form stacks, which are aligned side by side to form the Golgi ribbon. Two proteins, GRASP65 and GRASP55, previously implicated in stacking of cisternae, are shown to be required for the formation of the Golgi ribbon.

scholarly journals PAR3 and aPKC regulate Golgi organization through CLASP2 phosphorylation to generate cell polarity

2015 ◽  
Vol 26 (4) ◽  
pp. 751-761 ◽  
Author(s):  
Toshinori Matsui ◽  
Takashi Watanabe ◽  
Kenji Matsuzawa ◽  
Mai Kakeno ◽  
Nobumasa Okumura ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Golgi Apparatus ◽  
Cell Polarity ◽  
Cross Talk ◽  
Cell Polarization ◽  
Trans Golgi Network ◽  
Golgi Ribbon ◽  
Golgi Network ◽  
Golgi Organization

The organization of the Golgi apparatus is essential for cell polarization and its maintenance. The polarity regulator PAR complex (PAR3, PAR6, and aPKC) plays critical roles in several processes of cell polarization. However, how the PAR complex participates in regulating the organization of the Golgi remains largely unknown. Here we demonstrate the functional cross-talk of the PAR complex with CLASP2, which is a microtubule plus-end–tracking protein and is involved in organizing the Golgi ribbon. CLASP2 directly interacted with PAR3 and was phosphorylated by aPKC. In epithelial cells, knockdown of either PAR3 or aPKC induced the aberrant accumulation of CLASP2 at the trans-Golgi network (TGN) concomitantly with disruption of the Golgi ribbon organization. The expression of a CLASP2 mutant that inhibited the PAR3-CLASP2 interaction disrupted the organization of the Golgi ribbon. CLASP2 is known to localize to the TGN through its interaction with the TGN protein GCC185. This interaction was inhibited by the aPKC-mediated phosphorylation of CLASP2. Furthermore, the nonphosphorylatable mutant enhanced the colocalization of CLASP2 with GCC185, thereby perturbing the Golgi organization. On the basis of these observations, we propose that PAR3 and aPKC control the organization of the Golgi through CLASP2 phosphorylation.

scholarly journals The coiled-coil membrane protein golgin-84 is a novel rab effector required for Golgi ribbon formation

2003 ◽  
Vol 160 (2) ◽  
pp. 201-212 ◽  
Author(s):  
Aipo Diao ◽  
Dinah Rahman ◽  
Darryl J.C. Pappin ◽  
John Lucocq ◽  
Martin Lowe
Keyword(s):  
Golgi Apparatus ◽  
Mammalian Cells ◽  
Protein Transport ◽  
Coiled Coil ◽  
Specific Subset ◽  
Associated Proteins ◽  
Biochemical Approach ◽  
Golgi Ribbon ◽  
Golgi Network ◽  
Rab Effector

Fragmentation of the mammalian Golgi apparatus during mitosis requires the phosphorylation of a specific subset of Golgi-associated proteins. We have used a biochemical approach to characterize these proteins and report here the identification of golgin-84 as a novel mitotic target. Using cryoelectron microscopy we could localize golgin-84 to the cis-Golgi network and found that it is enriched on tubules emanating from the lateral edges of, and often connecting, Golgi stacks. Golgin-84 binds to active rab1 but not cis-Golgi matrix proteins. Overexpression or depletion of golgin-84 results in fragmentation of the Golgi ribbon. Strikingly, the Golgi ribbon is converted into mini-stacks constituting only ∼25% of the volume of a normal Golgi apparatus upon golgin-84 depletion. These mini-stacks are able to carry out protein transport, though with reduced efficiency compared with a normal Golgi apparatus. Our results suggest that golgin-84 plays a key role in the assembly and maintenance of the Golgi ribbon in mammalian cells.

scholarly journals Structure modeling hints at a granular organization of the Vertebrate Golgi ribbon

2021 ◽  
Author(s):  
Karen Page ◽  
Jessica McCormack ◽  
Mafalda Lopes-da-Silva ◽  
Francesca Patella ◽  
Kimberley Harrison-Lavoie ◽  
...  
Keyword(s):  
Golgi Apparatus ◽  
Secretory Granules ◽  
Ground Truth ◽  
Fine Grained ◽  
Fine Grained Structure ◽  
Best Fitting ◽  
Golgi Ribbon ◽  
Golgi Network ◽  
Von Willebrand ◽  
Ribbon Structures

Vertebrate cells display a specific Golgi apparatus architecture, known as the ribbon, where the functional subunits, the mini-stacks, are linked into a tri-dimensional network. The importance of the ribbon architecture is underscored by evidence of its disruption in a host of diseases, but just how it relates to the biological Golgi functions remains unclear. Are all the connections between mini-stacks functionally equal? Is the local structure of the ribbon of functional importance? These are difficult questions to address, due to the lack of a secretory cargo providing a quantifiable readout of the functional output of ribbon-embedded mini-stacks. Endothelial cells produce rod-shaped secretory granules, the Weibel-Palade bodies (WPB), whose von Willebrand Factor (VWF) cargo is central to hemostasis. In these cells, the Golgi apparatus exerts a dual control on WPB size at both mini-stack and ribbon levels. Mini-stack dimensions delimit the size of VWF boluses while the ribbon architecture allows their linear co-packaging at the trans-Golgi network generating WPBs of different lengths. This Golgi/WPB size relationship lends itself to mathematical analysis. Here, different ribbon structures were modeled and their predicted effects on WPB size distribution compared to the ground truth of experimental data. Strikingly, the best-fitting model describes a Golgi ribbon made by linked subunits corresponding to differentially functioning monomer and dimer mini-stacks. These results raise the intriguing possibility that the fine-grained structure of the Golgi ribbon is more complex than previously thought.

scholarly journals Disconnecting the Golgi ribbon from the centrosome prevents directional cell migration and ciliogenesis

2011 ◽  
Vol 193 (5) ◽  
pp. 917-933 ◽  
Author(s):  
Lidia Hurtado ◽  
Cristina Caballero ◽  
Maria P. Gavilan ◽  
Jesus Cardenas ◽  
Michel Bornens ◽  
...  
Keyword(s):  
Cell Migration ◽  
Golgi Apparatus ◽  
Mammalian Cells ◽  
Binding Domain ◽  
Dramatic Effect ◽  
Short Fragment ◽  
Golgi Ribbon ◽  
And Function ◽  
Directional Cell Migration ◽  
Interacting Domain

Mammalian cells exhibit a frequent pericentrosomal Golgi ribbon organization. In this paper, we show that two AKAP450 N-terminal fragments, both containing the Golgi-binding GM130-interacting domain of AKAP450, dissociated endogenous AKAP450 from the Golgi and inhibited microtubule (MT) nucleation at the Golgi without interfering with centrosomal activity. These two fragments had, however, strikingly different effects on both Golgi apparatus (GA) integrity and positioning, whereas the short fragment induced GA circularization and ribbon fragmentation, the large construct that encompasses an additional p150glued/MT-binding domain induced separation of the Golgi ribbon from the centrosome. These distinct phenotypes arose by specific interference of each fragment with either Golgi-dependent or centrosome-dependent stages of Golgi assembly. We could thus demonstrate that breaking the polarity axis by perturbing GA positioning has a more dramatic effect on directional cell migration than disrupting the Golgi ribbon. Both features, however, were required for ciliogenesis. We thus identified AKAP450 as a key determinant of pericentrosomal Golgi ribbon integrity, positioning, and function in mammalian cells.

scholarly journals Actin- and microtubule-dependent regulation of Golgi morphology by FHDC1

2016 ◽  
Vol 27 (2) ◽  
pp. 260-276 ◽  
Author(s):  
Sarah J. Copeland ◽  
Susan F. Thurston ◽  
John W. Copeland
Keyword(s):  
Golgi Apparatus ◽  
Actin Cytoskeleton ◽  
Cell Polarity ◽  
Intracellular Trafficking ◽  
Mammalian Cells ◽  
Microtubule Network ◽  
Microtubule Binding ◽  
Cytoskeletal Remodeling ◽  
Microtubule Binding Domain ◽  
Golgi Ribbon

The Golgi apparatus is the central hub of intracellular trafficking and consists of tethered stacks of cis, medial, and trans cisternae. In mammalian cells, these cisternae are stitched together as a perinuclear Golgi ribbon, which is required for the establishment of cell polarity and normal subcellular organization. We previously identified FHDC1 (also known as INF1) as a unique microtubule-binding member of the formin family of cytoskeletal-remodeling proteins. We show here that endogenous FHDC1 regulates Golgi ribbon formation and has an apparent preferential association with the Golgi-derived microtubule network. Knockdown of FHDC1 expression results in defective Golgi assembly and suggests a role for FHDC1 in maintenance of the Golgi-derived microtubule network. Similarly, overexpression of FHDC1 induces dispersion of the Golgi ribbon into functional ministacks. This effect is independent of centrosome-derived microtubules and instead likely requires the interaction between the FHDC1 microtubule-binding domain and the Golgi-derived microtubule network. These effects also depend on the interaction between the FHDC1 FH2 domain and the actin cytoskeleton. Thus our results suggest that the coordination of actin and microtubule dynamics by FHDC1 is required for normal Golgi ribbon formation.

scholarly journals GRASP55 Regulates Golgi Ribbon Formation

2008 ◽  
Vol 19 (7) ◽  
pp. 2696-2707 ◽  
Author(s):  
Timothy N. Feinstein ◽  
Adam D. Linstedt
Keyword(s):  
Cell Cycle ◽  
Golgi Apparatus ◽  
Cell Cycle Progression ◽  
Control Point ◽  
Gene Replacement ◽  
Mitogen Activated Protein Kinase ◽  
M Cell ◽  
Cycle Progression ◽  
G2 Phase ◽  
Golgi Ribbon

Recent work indicates that mitogen-activated protein kinase kinase (MEK)1 signaling at the G2/M cell cycle transition unlinks the contiguous mammalian Golgi apparatus and that this regulates cell cycle progression. Here, we sought to determine the role in this pathway of Golgi reassembly protein (GRASP)55, a Golgi-localized target of MEK/extracellular signal-regulated kinase (ERK) phosphorylation at mitosis. In support of the hypothesis that GRASP55 is inhibited in late G2 phase, causing unlinking of the Golgi ribbon, we found that HeLa cells depleted of GRASP55 show a fragmented Golgi similar to control cells arrested in G2 phase. In the absence of GRASP55, Golgi stack length is shortened but Golgi stacking, compartmentalization, and transport seem normal. Absence of GRASP55 was also sufficient to suppress the requirement for MEK1 in the G2/M transition, a requirement that we previously found depends on an intact Golgi ribbon. Furthermore, mimicking mitotic phosphorylation of GRASP55 by using aspartic acid substitutions is sufficient to unlink the Golgi apparatus in a gene replacement assay. Our results implicate MEK1/ERK regulation of GRASP55-mediated Golgi linking as a control point in cell cycle progression.

scholarly journals Caspase-mediated cleavage of the stacking protein GRASP65 is required for Golgi fragmentation during apoptosis

2002 ◽  
Vol 156 (3) ◽  
pp. 495-509 ◽  
Author(s):  
Jon D. Lane ◽  
John Lucocq ◽  
James Pryde ◽  
Francis A. Barr ◽  
Philip G. Woodman ◽  
...  
Keyword(s):  
Golgi Apparatus ◽  
Golgi Complex ◽  
Structural Component ◽  
Caspase 3 ◽  
Early Stage ◽  
Execution Phase ◽  
Resistant Form ◽  
Golgi Fragmentation ◽  
Golgi Ribbon ◽  
Caspase Substrate

The mammalian Golgi complex is comprised of a ribbon of stacked cisternal membranes often located in the pericentriolar region of the cell. Here, we report that during apoptosis the Golgi ribbon is fragmented into dispersed clusters of tubulo-vesicular membranes. We have found that fragmentation is caspase dependent and identified GRASP65 (Golgi reassembly and stacking protein of 65 kD) as a novel caspase substrate. GRASP65 is cleaved specifically by caspase-3 at conserved sites in its membrane distal COOH terminus at an early stage of the execution phase. Expression of a caspase-resistant form of GRASP65 partially preserved cisternal stacking and inhibited breakdown of the Golgi ribbon in apoptotic cells. Our results suggest that GRASP65 is an important structural component required for maintenance of Golgi apparatus integrity.

scholarly journals The ribbon architecture of the Golgi apparatus is not restricted to vertebrates

2021 ◽  
Author(s):  
Giovanna Benvenuto ◽  
Maria Ina Arnone ◽  
Francesco Ferraro
Keyword(s):  
Golgi Apparatus ◽  
Secretory Pathway ◽  
Sea Urchins ◽  
Embryonic Cells ◽  
Bilaterian Animal ◽  
Golgi Ribbon ◽  
Sorting Station ◽  
Cellular Feature ◽  
Multicellular Organisms ◽  
Structural Innovation

AbstractThe Golgi apparatus plays a central role as a processing and sorting station along the secretory pathway. In multicellular organisms, this organelle displays two structural organizations, whereby its functional subunits, the mini-stacks, are either dispersed throughout the cell or linked into a centralized structure, called Golgi “ribbon”. The Golgi ribbon is considered to be a feature typical of vertebrate cells. Here we report that this is not the case. We show that sea urchin embryonic cells assemble Golgi ribbons during early development. Sea urchins are deuterostomes, the bilaterian animal clade to which chordates, and thus vertebrates, also belong.Far from being a structural innovation of vertebrates, the Golgi ribbon therefore appears to be an ancient cellular feature evolved before the split between echinoderms and chordates. Evolutionary conservation of the ribbon architecture surmises that it must play fundamental roles in the biology of deuterostomes.

Relationship between golgi apparatus and axonal reticulum in sympathetic ganglion cells

1978 ◽  
Vol 36 (2) ◽  
pp. 598-599
Author(s):  
J. Quatacker ◽  
W. De Potter
Keyword(s):  
Golgi Apparatus ◽  
Sympathetic Ganglion ◽  
Phosphotungstic Acid ◽  
Ganglion Cells ◽  
Low Ph ◽  
Dense Core ◽  
Dense Core Vesicles ◽  
Large Dense Core Vesicles ◽  
Cervical Ganglia ◽  
Axoplasmic Reticulum

Mucopolysaccharides have been demonstrated biochemically in catecholamine-containing subcellular particles in different rat, cat and ox tissues. As catecholamine-containing granules seem to arise from the Golgi apparatus and some also from the axoplasmic reticulum we examined wether carbohydrate macromolecules could be detected in the small and large dense core vesicles and in structures related to them. To this purpose superior cervical ganglia and irises from rabbit and cat and coeliac ganglia and their axons from dog were subjected to the chromaffin reaction to show the distribution of catecholamine-containing granules. Some material was also embedded in glycolmethacrylate (GMA) and stained with phosphotungstic acid (PTA) at low pH for the detection of carbohydrate macromolecules.The chromaffin reaction in the perikarya reveals mainly large dense core vesicles, but in the axon hillock, the axons and the terminals, the small dense core vesicles are more prominent. In the axons the small granules are sometimes seen inside a reticular network (fig. 1).

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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