scholarly journals A Cyclingcis-Golgi Protein Mediates Endosome-to-Golgi Traffic

2004 ◽  
Vol 15 (11) ◽  
pp. 4798-4806 ◽  
Author(s):  
Rajalaxmi Natarajan ◽  
Adam D. Linstedt
Keyword(s):  
Steady State ◽  
Rna Interference ◽  
Shiga Toxin ◽  
Integral Membrane Protein ◽  
Endocytic Pathway ◽  
Toxin B ◽  
Recycling Endosomes ◽  
Late Endosomes ◽  
Golgi Protein ◽  
Endogenous Proteins

Toxins can invade cells by using a direct endosome-to-Golgi endocytic pathway that bypasses late endosomes/prelysosomes. This is also a route used by endogenous proteins, including GPP130, which is an integral membrane protein retrieved via the bypass pathway from endosomes to its steady-state location in the cis-Golgi. An RNA interference-based test revealed that GPP130 was required for efficient exit of Shiga toxin B-fragment from endosomes en route to the Golgi apparatus. Furthermore, two proteins whose Golgi targeting depends on endosome-to-Golgi retrieval in the bypass pathway accumulated in early/recycling endosomes in the absence of GPP130. GPP130 activity seemed specific to bypass pathway trafficking because the targeting of other tested proteins, including those retrieved to the Golgi via the more conventional late endosome route, was unaltered. Thus, a distally cycling Golgi protein mediates exit from endosomes and thereby underlies Shiga toxin invasion and retrieval-based targeting of other cycling Golgi proteins.

scholarly journals Direct Pathway from Early/Recycling Endosomes to the Golgi Apparatus Revealed through the Study of Shiga Toxin B-fragment Transport

1998 ◽  
Vol 143 (4) ◽  
pp. 973-990 ◽  
Author(s):  
Frédéric Mallard ◽  
Claude Antony ◽  
Danièle Tenza ◽  
Jean Salamero ◽  
Bruno Goud ◽  
...  
Keyword(s):  
Golgi Apparatus ◽  
Shiga Toxin ◽  
Brefeldin A ◽  
Adaptor Protein ◽  
Endocytic Pathway ◽  
Toxin B ◽  
Recycling Endosomes ◽  
Ultrastructural Studies ◽  
Late Endosomes ◽  
Rapid Kinetics

Shiga toxin and other toxins of this family can escape the endocytic pathway and reach the Golgi apparatus. To synchronize endosome to Golgi transport, Shiga toxin B-fragment was internalized into HeLa cells at low temperatures. Under these conditions, the protein partitioned away from markers destined for the late endocytic pathway and colocalized extensively with cointernalized transferrin. Upon subsequent incubation at 37°C, ultrastructural studies on cryosections failed to detect B-fragment–specific label in multivesicular or multilamellar late endosomes, suggesting that the protein bypassed the late endocytic pathway on its way to the Golgi apparatus. This hypothesis was further supported by the rapid kinetics of B-fragment transport, as determined by quantitative confocal microscopy on living cells and by B-fragment sulfation analysis, and by the observation that actin- depolymerizing and pH-neutralizing drugs that modulate vesicular transport in the late endocytic pathway had no effect on B-fragment accumulation in the Golgi apparatus. B-fragment sorting at the level of early/recycling endosomes seemed to involve vesicular coats, since brefeldin A treatment led to B-fragment accumulation in transferrin receptor–containing membrane tubules, and since B-fragment colocalized with adaptor protein type 1 clathrin coat components on early/recycling endosomes. Thus, we hypothesize that Shiga toxin B-fragment is transported directly from early/recycling endosomes to the Golgi apparatus. This pathway may also be used by cellular proteins, as deduced from our finding that TGN38 colocalized with the B-fragment on its transport from the plasma membrane to the TGN.

Trafficking of interleukin 2 and transferrin in endosomal fractions of T lymphocytes

1994 ◽  
Vol 107 (5) ◽  
pp. 1289-1295 ◽  
Author(s):  
V. Duprez ◽  
M. Smoljanovic ◽  
M. Lieb ◽  
A. Dautry-Varsat
Keyword(s):  
Horseradish Peroxidase ◽  
Interleukin 2 ◽  
Fluid Phase ◽  
Endocytic Pathway ◽  
Recycling Endosomes ◽  
High Affinity ◽  
Human T Cell ◽  
Late Endosomes ◽  
Discontinuous Sucrose Gradient ◽  
Acidic Organelles

The T lymphocyte growth factor interleukin 2 binds to surface high-affinity receptors and is rapidly internalized and degraded in acidic organelles. The alpha and beta chains of high-affinity interleukin 2 receptors are internalized together with interleukin 2. To identify the intracellular pathway followed by interleukin 2, we have compared the subcellular distribution of interleukin 2, transferrin and a fluid-phase marker, horseradish peroxidase, in the human T cell line IARC 301.5. Transferrin was used as a marker of early and recycling endosomes, and horseradish peroxidase to probe for the whole endocytic pathway. Fractionation of intracellular organelles on a discontinuous sucrose gradient showed that internalized interleukin 2 is initially mostly found in compartments with similar densities to transferrin, e.g. early and recycling endosomes. The kinetics of entry and exit of interleukin 2 from such organelles was much slower than that of transferrin. Later on, interleukin 2 is predominantly found in dense lysosome-containing fractions. Very little, if any, interleukin 2 was found in fractions corresponding to late endosomes containing horseradish peroxidase. These results suggest that, after endocytosis, interleukin 2 enters early or recycling endosomes before it reaches dense lysosomes.

Study of Shiga toxin b-fragment transport from early/recycling endosomes to the Golgi apparatus

1998 ◽  
Vol 90 (3) ◽  
pp. 288-288
Author(s):  
Frédéric Mallard ◽  
Danièle Tenza ◽  
Claude Antony ◽  
Jean Salamero ◽  
Bruno Goud ◽  
...  
Keyword(s):  
Golgi Apparatus ◽  
Shiga Toxin ◽  
Toxin B ◽  
Recycling Endosomes

Autophagy gene ATG7 regulates albumin transcytosis in renal tubule epithelial cells

2021 ◽  
Author(s):  
Yushi Uchida ◽  
Kumiko Torisu ◽  
Kenji Ueki ◽  
Kazuhiko Tsuruya ◽  
Toshiaki Nakano ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Proximal Tubule ◽  
Intracellular Trafficking ◽  
Renal Tubule ◽  
Degradation Pathway ◽  
Endocytic Pathway ◽  
Recycling Endosomes ◽  
Autophagy Gene ◽  
Late Endosomes ◽  
Evolutionarily Conserved

Receptor-mediated albumin transport in proximal tubule epithelial cells (PTECs) is important to control proteinuria. Autophagy is an evolutionarily conserved degradation pathway and its role in intracellular trafficking through interaction with the endocytic pathway has recently been highlighted. Here, we determined whether autophagy regulates albumin transcytosis in PTECs and suppresses albumin-induced cytotoxicity using human proximal tubule (HK-2) cells. Neonatal Fc-receptor (FcRn), a receptor for albumin transcytosis, partially co-localized with autophagosomes. Recycling of FcRn was attenuated and FcRn accumulated in autophagy related 7 (ATG7) knockdown HK-2 cells. Co-localization of FcRn with RAB7-positive late endosomes and RAB11-positive recycling endosomes was reduced in ATG7 knockdown cells, resulting in decreased recycling of FcRn to the plasma membrane. In ATG7 knockdown cells, albumin transcytosis was significantly reduced and intracellular albumin accumulation was increased. Finally, release of KIM-1, a marker of tubule injury, from ATG7 knockdown cells was increased in response to excess albumin. In conclusion, suppression of autophagy in tubules impairs FcRn transport, thereby inhibiting albumin transcytosis. The resulting accumulation of albumin induces cytotoxicity in tubules.

scholarly journals Endocytosis of interleukin 2 receptors in human T lymphocytes: distinct intracellular localization and fate of the receptor alpha, beta, and gamma chains.

1995 ◽  
Vol 129 (1) ◽  
pp. 55-64 ◽  
Author(s):  
A Hémar ◽  
A Subtil ◽  
M Lieb ◽  
E Morelon ◽  
R Hellio ◽  
...  
Keyword(s):  
Intracellular Localization ◽  
Interleukin 2 ◽  
Surface Protein ◽  
Degradation Pathway ◽  
Endocytic Pathway ◽  
Gamma Chain ◽  
Recycling Endosomes ◽  
Alpha Chain ◽  
Late Endosomes ◽  
Alpha Beta

Members of the cytokine receptor family are composed of several noncovalently linked chains with sequence and structure homologies in their extracellular domain. Receptor subfamily members share at least one component: thus the receptors for interleukin (IL) 2 and IL15 have common beta and gamma chains, while those for IL2, 4, 7, and 9 have a common gamma chain. The intracellular pathway followed by IL2 receptors after ligand binding and endocytosis was analyzed by immunofluorescence and confocal microscopy in a human T lymphocytic cell line. Surprisingly, the alpha, beta, and gamma chains had different intracellular localizations after being endocytosed together. The alpha chain was always in transferrin-positive compartments (early/recycling endosomes), both at early and late internalization times, but was never detected in rab7-positive compartments (late endosomes). On the other hand, at late internalization times, the beta and gamma chains were excluded from transferrin-positive organelles and did not colocalize with alpha. Furthermore, beta could be found in rab7-positive vesicles. These differences suggest that the alpha chain recycles to the plasma membrane, while the beta and gamma chains are sorted towards the degradation pathway. The half-lives of these three chains on the cell surface also reflect their different intracellular fates after endocytosis. The beta and gamma chains are very short-lived polypeptides since their half-life on the surface is only approximately 1 h, whereas alpha is a much more stable surface protein. This shows for the first time that components of a multimeric receptor can be sorted separately along the endocytic pathway.

scholarly journals Relationship between invariant chain expression and major histocompatibility complex class II transport into early and late endocytic compartments.

1993 ◽  
Vol 177 (3) ◽  
pp. 583-596 ◽  
Author(s):  
P Romagnoli ◽  
C Layet ◽  
J Yewdell ◽  
O Bakke ◽  
R N Germain
Keyword(s):  
Major Histocompatibility Complex ◽  
Mhc Class Ii ◽  
Class Ii ◽  
Endocytic Pathway ◽  
Invariant Chain ◽  
Major Histocompatibility ◽  
Histocompatibility Complex ◽  
Late Endosomes ◽  
Early Endosomes ◽  
Endocytic Compartments

Invariant chain (Ii), which associates with major histocompatibility complex (MHC) class II molecules in the endoplasmic reticulum, contains a targeting signal for transport to intracellular vesicles in the endocytic pathway. The characteristics of the target vesicles and the relationship between Ii structure and class II localization in distinct endosomal subcompartments have not been well defined. We demonstrate here that in transiently transfected COS cells expressing high levels of the p31 or p41 forms of Ii, uncleaved Ii is transported to and accumulates in transferrin-accessible (early) endosomes. Coexpressed MHC class II is also found in this same compartment. These early endosomes show altered morphology and a slower rate of content movement to later parts of the endocytic pathway. At more moderate levels of Ii expression, or after removal of a highly conserved region in the cytoplasmic tail of Ii, coexpressed class II molecules are found primarily in vesicles with the characteristics of late endosomes/prelysosomes. The Ii chains in these late endocytic vesicles have undergone proteolytic cleavage in the lumenal region postulated to control MHC class II peptide binding. These data indicate that the association of class II with Ii results in initial movement to early endosomes. At high levels of Ii expression, egress to later endocytic compartments is delayed and class II-Ii complexes accumulate together with endocytosed material. At lower levels of Ii expression, class II-Ii complexes are found primarily in late endosomes/prelysosomes. These data provide evidence that the route of class II transport to the site of antigen processing and loading involves movement through early endosomes to late endosomes/prelysosomes. Our results also reveal an unexpected ability of intact Ii to modify the structure and function of the early endosomal compartment, which may play a role in regulating this processing pathway.

scholarly journals Switching Shiga Toxin (Stx) Type from Stx2d to Stx2a but Not Stx2c Alters Virulence of Stx-Producing Escherichia coli (STEC) Strain B2F1 in Streptomycin (Str)-Treated Mice

Toxins ◽  
2021 ◽  
Vol 13 (1) ◽  
pp. 64
Author(s):  
Beth A. McNichol ◽  
Rebecca A. Bova ◽  
Kieron Torres ◽  
Lan N. Preston ◽  
Angela R. Melton-Celsa
Keyword(s):  
Escherichia Coli ◽  
Amino Acid ◽  
Oral Administration ◽  
Amino Acid Composition ◽  
Shiga Toxin ◽  
Vero Cells ◽  
Toxin B ◽  
B Subunit ◽  
Intestinal Mucus ◽  
Binding Subunit

Shiga toxin (Stx)-producing Escherichia coli (STEC) strain B2F1 produces Stx type 2d, a toxin that becomes more toxic towards Vero cells in the presence of intestinal mucus. STEC that make Stx2d are more pathogenic to streptomycin (Str)-treated mice than most STEC that produce Stx2a or Stx2c. However, purified Stx2d is only 2- or 7-fold more toxic by the intraperitoneal route than Stx2a or Stx2c, respectively. We hypothesized, therefore, that the toxicity differences among Stx2a, Stx2c, and Stx2d occur at the level of delivery from the intestine. To evaluate that hypothesis, we altered the toxin type produced by stx2d+ mouse virulent O91:H21 clinical isolate B2F1 to Stx2a or Stx2c. Because B2F1 encodes two copies of stx2d, we did these studies in a derivative of B2F1 in which stx2d1 was deleted. Although the strains were equivalently virulent to the Str-treated mice at the 1010 dose, the B2F1 strain that produced Stx2a was attenuated relative to the ones that produced Stx2d or Stx2c when administered at 103 CFU/mouse. We next compared the oral toxicities of purified Stx2a, Stx2c, and Stx2d. We found that purified Stx2d is more toxic than Stx2a or Stx2c upon oral administration at 4 µg/mouse. Taken together, these studies suggest that Stx2 toxins are most potent when delivered directly from the bacterium. Furthermore, because Stx2d and Stx2c have the identical amino acid composition in the toxin B subunit, our results indicate that the virulence difference between Stx2a and Stx2d and Stx2c resides in the B or binding subunit of the toxins.

Rab22a affects the morphology and function of the endocytic pathway

2001 ◽  
Vol 114 (22) ◽  
pp. 4041-4049 ◽  
Author(s):  
Rosana Mesa ◽  
Cristina Salomón ◽  
Marcelo Roggero ◽  
Philip D. Stahl ◽  
Luis S. Mayorga
Keyword(s):  
Fluorescent Protein ◽  
Fluid Phase ◽  
Small Gtpases ◽  
Endocytic Pathway ◽  
Site Directed Mutagenesis ◽  
Rab Proteins ◽  
Rab Protein ◽  
Late Endosomes ◽  
And Function ◽  
Negative Mutant

Soon after endocytosis, internalized material is sorted along different pathways in a process that requires the coordinated activity of several Rab proteins. Although abundant information is available about the subcellular distribution and function of some of the endocytosis-specific Rabs (e.g. Rab5 and Rab4), very little is known about some other members of this family of proteins. To unveil some of the properties of Rab22a, one of the less studied endosome-associated small GTPases, we have expressed the protein tagged with the green fluorescent protein in CHO cells. The results indicate that Rab22a associates with early and late endosomes (labeled by a 5 minute rhodamine-transferrin uptake and the cation-independent mannose 6-phosphate receptor, respectively) but not with lysosomes (labeled by 1 hour rhodamine horseradish peroxidase uptake followed by 1 hour chase). Overexpression of the protein causes a prominent morphological enlargement of the early and late endosomes. Two mutants were generated by site-directed mutagenesis, a negative mutant (Rab22aS19N, with reduced affinity for GTP) and a constitutively active mutant (Rab22aQ64L, with reduced endogenous GTPase activity). The distribution of the negative mutant was mostly cytosolic, whereas the positive mutant associated with early and late endosomes and, interestingly also with lysosomes and autophagosomes (labeled with monodansylcadaverine). Cells expressing Rab22a wild type and Rab22aS19N displayed decreased endocytosis of a fluid phase marker. Conversely, overexpression of Rab22aQ64L, which strongly affects the morphology of endosomes, did not inhibit bulk endocytosis. Our results show that Rab22a has a unique distribution along the endocytic pathway that is not shared by any other Rab protein, and that it strongly affects the morphology and function of endosomes.

A System for Production and Rapid Purification of Large Amounts of the Shiga Toxin/Shiga-Like Toxin B Subunit

1991 ◽  
pp. 299-301
Author(s):  
Arthur Donohue-Rolfe ◽  
David W. K. Acheson ◽  
Gerald T. Keusch ◽  
Marcia B. Goldberg ◽  
Stephanie A. Boyko ◽  
...  
Keyword(s):  
Shiga Toxin ◽  
Toxin B ◽  
B Subunit ◽  
Rapid Purification

scholarly journals Trafficking of prion proteins through a caveolae-mediated endosomal pathway

2003 ◽  
Vol 162 (4) ◽  
pp. 703-717 ◽  
Author(s):  
Peter J. Peters ◽  
Alexander Mironov ◽  
David Peretz ◽  
Elly van Donselaar ◽  
Estelle Leclerc ◽  
...  
Keyword(s):  
Prion Proteins ◽  
Protein A ◽  
Subcellular Location ◽  
Cellular Prion Protein ◽  
Endocytic Pathway ◽  
Live Cells ◽  
Trafficking Pathway ◽  
Late Endosomes ◽  
Endosomal Pathway ◽  
Glycosylphosphatidyl Inositol

To understand the posttranslational conversion of the cellular prion protein (PrPC) to its pathologic conformation, it is important to define the intracellular trafficking pathway of PrPC within the endomembrane system. We studied the localization and internalization of PrPC in CHO cells using cryoimmunogold electron microscopy. At steady state, PrPC was enriched in caveolae both at the TGN and plasma membrane and in interconnecting chains of endocytic caveolae. Protein A–gold particles bound specifically to PrPC on live cells. These complexes were delivered via caveolae to the pericentriolar region and via nonclassical, caveolae-containing early endocytic structures to late endosomes/lysosomes, thereby bypassing the internalization pathway mediated by clathrin-coated vesicles. Endocytosed PrPC-containing caveolae were not directed to the ER and Golgi complex. Uptake of caveolae and degradation of PrPC was slow and sensitive to filipin. This caveolae-dependent endocytic pathway was not observed for several other glycosylphosphatidyl inositol (GPI)-anchored proteins. We propose that this nonclassical endocytic pathway is likely to determine the subcellular location of PrPC conversion.

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