• Molecules and Cells
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• 제46권4호
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• pp.191-199
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• 2023

The Golgi apparatus modifies and transports secretory and membrane proteins. In some instances, the production of secretory and membrane proteins exceeds the capacity of the Golgi apparatus, including vesicle trafficking and the post-translational modification of macromolecules. These proteins are not modified or delivered appropriately due to the insufficiency in the Golgi function. These conditions disturb Golgi homeostasis and induce a cellular condition known as Golgi stress, causing cells to activate the 'Golgi stress response,' which is a homeostatic process to increase the capacity of the Golgi based on cellular requirements. Since the Golgi functions are diverse, several response pathways involving TFE3, HSP47, CREB3, proteoglycan, mucin, MAPK/ETS, and PERK regulate the capacity of each Golgi function separately. Understanding the Golgi stress response is crucial for revealing the mechanisms underlying Golgi dynamics and its effect on human health because many signaling molecules are related to diseases, ranging from viral infections to fatal neurodegenerative diseases. Therefore, it is valuable to summarize and investigate the mechanisms underlying Golgi stress response in disease pathogenesis, as they may contribute to developing novel therapeutic strategies. In this review, we investigate the perturbations and stress signaling of the Golgi, as well as the therapeutic potentials of new strategies for treating Golgi stress-associated diseases.

• Applied Microscopy
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• 제28권2호
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• pp.159-170
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• 1998

The glandular secretory system of the capitate gandular trichomes in leaf of Thymus quinquecostatus Celakovsky was examined by transmission electron microscope. The glandular trichome was consisted of three cell layers; an basal cell layer, a stalk cell with single-celled intermediate layer and a discoid secretory layer with thickened cuticle. The secretory cell was dense, rich in mitochondria, rER, plastds, Golgi complex and had many vesicular structure. Typical plastids with reticulate body and plastoglobule were present in glandular trichome. The tytoplasm of secretory cell was filled with osmiophilic secretory materials. The secretory vesicles, originated from Golgi complex, appeared as membrane bounded vesicles and secreted to the outer wall surface. The presences of well developed rER, mitochondria, Golgi complex, and membrane-bounded vesicles fused with plasmalemma in the secreting cells indicate that the granulocrine mechanism of secretion was occurring in T. quinquecostatus. Subcuticular cavity was developed between the cuticular layer and the secretory cell wall, and it formed above the secretory cell upon separation of cuticle-wall.

• 분석과학
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• 제29권1호
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• pp.10-18
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• 2016

Phosphodiesterase(PDE)는 세포내에서 cAMP를 분해하는 효소로 세포의 신호 전달에 중요한 기능을 수행하는 것으로 알려져 왔다. 이전의 연구를 통해 군소에서 클로닝된 PDE4 long-form의 N-말단에 위치하는 16개 아미노산만으로 충분히 원형질막에 타기팅됨을 알 수 있었다. 본 연구에서는 ApPDE4의 N-말단 16개(L(N16))를 주형으로 해서 9-11번째와 15번째 아미노산들(RHW-C)을 무작위적으로 아마노산에 돌연변이를 주어서 세포내 타기팅에 미치는 영향을 분석해 보았다. 본 연구를 통해 원형질막과 골지체로 타기팅되는 돌연변이체들과 골지체로만 타기팅되는 돌연변이체들과, 소포체와 골지체로 동시에 타기팅되는 돌연변이체들과, 세포질에만 위치하는 돌연변이체들을 얻을 수 있었다. 또한, 이러한 타기팅에 palmitoylation이 영향을 주는지 확인하기 위해 palmitoylation 억제제인 2-BR을 처리해보니 대부분의 돌연변이체에서 원형질막 타기팅이 사라지는 것을 확인하였다. 이를통해 palmitoylation이 ApPDE4 돌연변이체들의 원형질막 타기팅에 중요하다는 사실을 확인할 수 있었다. 또한, 이들 돌연변이체들중 골지체로만 타기팅되는 L(N16,C3S/VV/G)-mRFP와 L(N16,C3S/LFS/R)-mRFP와 L(N16,EPL/R)-mRFP들의 경우는 골지체 타기팅에 인지질 중에 하나인 PI4P가 중요한 역할을 하는 것을 알 수 있었다.

• Applied Microscopy
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• 제22권2호
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• pp.46-65
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• 1992

In this study, we have made morphological and cytochemical observations to investigate the type of Golgi apparatus around the bile canaliculus. The animal (Wister, $220{\sim}250gm$) were divided into 4 groups; normal, hydrochol, colchicine and hydrochol-colchicine. The Golgi apparatus is classified into 16 different types from 4 different groups. In the normal group, we could observe 12 different types of the sixteen. Type I which showed convexed cisterns facing the bile canaliculi was most abundant of the types. In the hydrochol group, 14 types were observed. Type VII and type I showed convexed cisterns facing the bile canaliculus and were abundant. In the colchicine group, 11 different types were viewed and type XIV which showed intensely dilated cisterns without the polarity was predominant. In the hydrochol-colchicine group, we observed 3 different types. Type XIV clearly showed the highest percentage, although that type was less numerous in this group than in the colchicine group. In the hydrochol group, the Golgi apparatus showed a tendency to increase in numbers, while in the hydrochol-colchicine group the Golgi apparatus showed a tendency to decrease in numbers. The reactive products of thiamine pyrophosphatase and acid phosphatase were apparent over the distal Golgi cistern in the normal and hydrochol groups, but were decreased or not observed in the colchicine and hydrochol-colchicine groups. From the results, it is assumed that with the presence of the microtubule, Golgi cisterns are dilated with polarity after stimulation of secretion. Without the microtubule, the cistern becomes more intensely dilated and none polaric. Also the enzymes within the cisternal membrane become decreaed or absent and the Golgi apparatus decreases in numbers after activation of secretion.

• Bulletin of the Korean Chemical Society
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• 제30권9호
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• pp.1981-1984
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• 2009

Subcellular localization of protein kinase often plays an important role in determining its activity and specificity. Protein kinase C (PKC), a family of multi-gene protein kinases has long been known to be translocated to the particular cellular compartments in response to DAG or its analog phorbol esters. We used C-terminal green fluorescent protein (GFP) fusion proteins of PKC isoforms to visualize the subcellular distribution of individual PKC isoforms. Intracellular localization of PKC-GFP proteins was monitored by fluorescence microscopy after transient transfection of PKC-GFP expression vectors in the HeLa cells. In unstimulated HeLa cells, all PKC isoforms were found to be distributed throughout the cytoplasm with a few exceptions. PKC$\theta$ was mostly localized to the Golgi, and PKC$\gamma$, PKC$\delta$ and PKC$\eta$ showed cytoplasmic distribution with Golgi localization. DAG analog TPA induced translocation of PKC-GFP to the plasma membrane. PKC$\alpha$, PKC$\eta$ and PKC$\theta$ were also localized to the Golgi in response to TPA. Only PKC$\delta$ was found to be associated with the nuclear membrane after transient TPA treatment. These results suggest that specific PKC isoforms are translocated to different intracellular sites and exhibit distinct biological effects.

• Molecules and Cells
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• 제41권1호
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• pp.50-54
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• 2018

Atg5 and Atg7 have long been considered as essential molecules for autophagy. However, we found that cells lacking these molecules still form autophagic vacuoles and perform autophagic protein degradation when subjected to certain stressors. During this unconventional autophagy pathway, autophagosomes appeared to be generated in a Rab9-dependent manner by the fusion of vesicles derived from the trans-Golgi and late endosomes. Therefore, mammalian autophagy can occur via at least two different pathways; the Atg5/Atg7-dependent conventional pathway and an Atg5/Atg7-independent alternative pathway.

• Molecules and Cells
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• 제40권9호
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• pp.643-654
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• 2017

Autophagy is a degradation pathway in eukaryotic cells in which aging proteins and organelles are sequestered into double-membrane vesicles, termed autophagosomes, which fuse with vacuoles to hydrolyze cargo. The key step in autophagy is the formation of autophagosomes, which requires different kinds of vesicles, including COPII vesicles and Atg9-containing vesicles, to transport lipid double-membranes to the phagophore assembly site (PAS). In yeast, the cis-Golgi localized t-SNARE protein Sed5 plays a role in endoplasmic reticulum (ER)-Golgi and intra-Golgi vesicular transport. We report that during autophagy, sed5-1 mutant cells could not properly transport Atg8 to the PAS, resulting in multiple Atg8 dots being dispersed into the cytoplasm. Some dots were trapped in the Golgi apparatus. Sed5 regulates the anterograde trafficking of Atg9-containing vesicles to the PAS by participating in the localization of Atg23 and Atg27 to the Golgi apparatus. Furthermore, we found that overexpression of SFT1 or SFT2 (suppressor of sed5 ts) rescued the autophagy defects in sed5-1 mutant cells. Our data suggest that Sed5 plays a novel role in autophagy, by regulating the formation of Atg9-containing vesicles in the Golgi apparatus, and the genetic interaction between Sft1/2 and Sed5 is essential for autophagy.

• Applied Microscopy
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• 제25권2호
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• pp.29-38
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• 1995

The fine structure of the hemocytes in Wolf spider, Pardosa astrigera, is discribed and compared with that of similar cells in other spider species and insects. Five hemocyte types are identified in the hemolymph: prohemocyte, plasmatocyte, granulocyte, spherulocyte and adipohemocyte. Prohemocytes are small with a relatively undifferentiated cytoplasm. The nucleus is comparatively large and has a perinuclear space. Plasmatocytes and granulocytes are pinocytotic function in the hemolymph of the body. The plasmatocytes have some coated pits on the plasma membrane and well developed Golgi complex, The granulocytes appear sequence of events in the formation of coated vesicle from a coated pit on its plasma membrane. Golgi complex become well expressed and give rise to small secretory vesicles which fuse to large bodies. The spherulocytes are larger in cell size than other hemocytes. Their cytoplasm is filled with spherules. The spherules contain the floccurent materials and the helical structured materials, which are 220nm in length and 80nm in width. The adipohemocytes are oval shaped and have a number of lipid droplets.

• Applied Microscopy
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• 제17권2호
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• pp.23-30
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• 1987

There are groups of large monopolar cells containing numerous secretory inclusions in the muscular and connective tissue. These cells contain the electron-lucent vesicles in the size of $0.5{\sim}0.9{\mu}m$, which are secreted to the exterior of the tentacle through their cytoplasmic processes projected to the epithelial layer. Secretory material can be seen accumulating in swollen portions of the granular endoplasmic reticulum. It is postulated that this material is transported to the Golgi-complex and thus the limiting membrane of the inclusions is derived from the Golgi-membrane. An electron lucent material secreted from these cells seems to be similar to fibrous electron lucent material filled in the brush border of the epidermis.

• 한국미생물생명공학회:학술대회논문집
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• 한국미생물생명공학회 2004년도 Annual Meeting BioExibition International Symposium
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• pp.152-154
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• 2004