Mdm2-mediated ubiquitination of PKCβII in the nucleus mediates clathrin-mediated endocytic activity

p67 is a lysosomal type I membrane glycoprotein of Trypanosoma brucei. In procyclic stage cells p67 trafficks to the lysosome without modification, but in the bloodstream stage Golgi processing adds poly-N-acetyllactosamine to N-glycans. In both stages proteolytic fragmentation occurs in the lysosome, but turnover is approximately nine times faster in bloodstream cells. Trafficking of wildtype p67 and mutants missing the cytoplasmic (p67ΔCD) or cytoplasmic/transmembrane domains (p67ΔTM) was monitored by pulse-chase,surface biotinylation and immunofluorescence. Overexpressed wildtype p67 trafficks normally in procyclics, but some leaks to the cell surface suggesting that the targeting machinery is saturable. p67ΔCD and p67ΔTM are delivered to the cell surface and secreted, respectively. The membrane/cytoplasmic domains function correctly in procyclic cells when fused to GFP indicating that these domains are sufficient for stage-specific lysosomal targeting. In contrast, p67 wildtype and deletion reporters are overwhelmingly targeted to the lysosome and degraded in bloodstream cells. These findings suggest that either redundant developmentally regulated targeting signals/machinery are operative in this stage or that the increased endocytic activity of bloodstream cells prevents export of the deletion reporters.

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The endocytic activity of dendritic cells.

Journal of Experimental Medicine ◽

10.1084/jem.182.2.283 ◽

1995 ◽

Vol 182 (2) ◽

pp. 283-288 ◽

Cited By ~ 201

Author(s):

R M Steinman ◽

J Swanson

Keyword(s):

Dendritic Cells ◽

Endocytic Activity

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Appearance and endocytic activity of epithelial cells from human efferent ducts in primary monolayer culture

Cell and Tissue Research ◽

10.1007/bf00645053 ◽

1992 ◽

Vol 270 (3) ◽

pp. 513-519 ◽

Cited By ~ 3

Author(s):

S. Raczek ◽

C. H. Yeung ◽

L. Hertle ◽

H. Schulze ◽

T. G. Cooper

Keyword(s):

Epithelial Cells ◽

Monolayer Culture ◽

Efferent Ducts ◽

Primary Monolayer Culture ◽

Primary Monolayer ◽

Endocytic Activity

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Signaling from Epithelial to Dendritic Cells of the Thyroid Gland: Evidence for Thyrocyte-Derived Factors Controlling the Survival, Multiplication, and Endocytic Activity of Dendritic Cells

Laboratory Investigation ◽

10.1038/labinvest.3780374 ◽

2001 ◽

Vol 81 (12) ◽

pp. 1601-1613 ◽

Cited By ~ 3

Author(s):

Karine Croizet ◽

Séverine Trouttet-Masson ◽

Rachida Rabilloud ◽

Jean-Francois Nicolas ◽

Françoise Bernier-Valentin ◽

...

Keyword(s):

Dendritic Cells ◽

Thyroid Gland ◽

Endocytic Activity

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Trans-order yolk protein can stimulate endocytic activity inDrosophilaoocytes

Invertebrate Reproduction & Development ◽

10.1080/07924259.2011.574843 ◽

2011 ◽

Vol 55 (4) ◽

pp. 222-229 ◽

Cited By ~ 1

Author(s):

Patrick T. Brown ◽

Richard I. Woodruff

Keyword(s):

Yolk Protein ◽

Endocytic Activity

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Glucocorticoids increase the endocytic activity of human dendritic cells

International Immunology ◽

10.1093/intimm/11.9.1519 ◽

1999 ◽

Vol 11 (9) ◽

pp. 1519-1526 ◽

Cited By ~ 63

Author(s):

Lorenzo Piemonti ◽

Paolo Monti ◽

Paola Allavena ◽

Biagio Eugenio Leone ◽

Alessandra Caputo ◽

...

Keyword(s):

Dendritic Cells ◽

Endocytic Activity ◽

Human Dendritic Cells

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Internalization of styryl dye FM1-43 in the hair cells of lateral line organs in Xenopus larvae.

Journal of Histochemistry & Cytochemistry ◽

10.1177/44.7.8675994 ◽

1996 ◽

Vol 44 (7) ◽

pp. 733-741 ◽

Cited By ~ 48

Author(s):

S Nishikawa ◽

F Sasaki

Keyword(s):

Endoplasmic Reticulum ◽

Lateral Line ◽

Hair Cells ◽

Divalent Cations ◽

Apical Part ◽

Cation Channel ◽

Monovalent Cations ◽

Photo Oxidation ◽

Styryl Dye ◽

Endocytic Activity

We used a fluorescent dye, FM1-43 to investigate mechanotransduction mechanisms in the hair cells of lateral line organs of Xenopus larvae. FM1-43 specifically labeled the hair cells. The photo-oxidation technique was performed with election microscopy to examine the labeling sites and their mechanisms. The results showed that the labeling sites were mitochondria and rough endoplasmic reticulum throughout the cytoplasm. Endocytic activity of the hair cells was limited to endosomes and small granules located at the apical part of the cells. Blockers of the mechanosensitive cation channel (neomycin, gentamicin, streptomycin, and amiloride) effectively inhibited FM1-43 labeling. One of the blockers, amiloride, was found to bind to hair cells when its fluorescence was examined. Divalent cations such as Mg2+ and Ca2+, but not monovalent cations such as Na+ and K+, inhibited FM1-43 labeling when they were added in excess amounts. These results suggest that FM1-43 internalizes hair cells via the putative mechanosensitive cation channel in the plasma membrane.

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Intracellular formation of calcium concretions by phagocytic cells in freshwater mussels

Canadian Journal of Zoology ◽

10.1139/z89-027 ◽

1989 ◽

Vol 67 (1) ◽

pp. 198-207 ◽

Cited By ~ 10

Author(s):

Harold Silverman ◽

Pamela E. Richard ◽

Russell H. Goddard ◽

Thomas H. Dietz

Keyword(s):

Connective Tissue ◽

Colloidal Gold ◽

Synthetic Activity ◽

Stereo Pair ◽

Phagocytic Cells ◽

India Ink ◽

Transmission Electron ◽

Tissue Cells ◽

Endocytic Activity ◽

Endocytic Vesicles

The gills of freshwater unionid mussels contain large accumulations of extracellular calcium phosphate concretions. Connective tissue cells located in specific areas in the gills of these animals are the site of concretion formation. The cell type responsible for concretion formation appears to differentiate from an undifferentiated precursor cell by accumulating endocytic vesicles and producing amorphous membrane-bound granules from active rough endoplasmic reticulum and Golgi apparatus. In the most mature of the cells, these granules occupy most of the cytoplasm. Concretions are initiated within the amorphous granules as observed using stereo-pair transmission electron microscopy. These connective tissue cells exhibit phagocytosis, and can ingest India ink particles and colloidal gold. Colloidal gold is internalized through an endocytic mechanism within vesicles. Gold can be observed in the amorphous granules, implying fusion of such endocytic vesicles with the amorphous granules. While the exact mechanism of concretion formation is not understood, the cellular site of formation has been identified. Further, protein synthetic activity as well as endocytic activity appear necessary for concretion production.

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