A heterotrimeric G protein, Gα1−3, on Golgi membranes regulates the secretion of heparan sulfate proteoglycan in LLC-PK1 epithelial cells

Stow, Jennifer L.; Almeida, Joanna; Narula, Navneet; Holtzman, Eric; Ercolani, Louis; Ausiello, Dennis A.

doi:10.1016/0962-8924(92)90127-9

Cited by 60 publications

(106 citation statements)

References 4 publications

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“…The notion that G protein activation stimulates budding would seem to contradict the data that activation of Gi3 inhibits traffic through the Golgi (Stow et al, 1991) and that activation of a Gi inhibits budding from the TGN (Barr et al, 1991). However, much as adenylyl cyclase can be stimulated or inhibited by different G proteins, traffic though the Golgi and other compartments might be subject to both positive and negative control by antagonistic G proteins.…”

Section: G Proteins and Cellular Regulation: Cross-talk Between Signamentioning

confidence: 44%

“…Gjia3 is normally partially bound to the cytoplasmic surface of membranes of the Golgi apparatus (Ercolani et al, 1990;Stow et al, 1991). Overexpression of Gia 3 by transfection slows traffic of proteoglycans through the Golgi.…”

mentioning

confidence: 99%

“…Pertussis toxin reverses this effect and accelerates traffic in non-transfected cells (Stow et al, 1991). GTPyS or AIF4-block vesicle production.…”

mentioning

confidence: 99%

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Role of heterotrimeric G proteins in membrane traffic.

Bomsel

Mostov

1992

MBoC

207

142

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Section: G Proteins and Cellular Regulation: Cross-talk Between Signamentioning

confidence: 44%

mentioning

confidence: 99%

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Role of heterotrimeric G proteins in membrane traffic.

Bomsel

Mostov

1992

MBoC

207

142

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“…G i1 and G i2 are located to the plasma membrane; G i3 is located to the Golgi, where it regulates intraand trans-Golgi trafficking and exocytosis [37,38]. Because T lymphocytes rely on autocrine production of cytokines for their proliferation, disruption of the Golgi structure, which probably explains that viable Jurkat cells expressing G ␣i3 mutants could not be obtained, would affect IL-2 secretion.…”

Section: Discussionmentioning

confidence: 99%

Positive regulation of human T cell activation by Gi2 proteins and interleukin-8

Lippert

Jacques

Hermouet

2000

Journal of Leukocyte Biology

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We investigated whether pertussis toxin (PT)-sensitive heterotrimeric G i proteins (G i1 , G i2 , G i3 ) are involved in the regulation of TCR-induced activation of human T cells. First, G i proteins were inactivated by PT: pretreatment with PT of purified blood T lymphocytes before CD3 cross-linking inhibited cell proliferation (؊71.1 ؎ 22.0%, P F 0.001), production of interleukin-2 (IL-2; ؊47.3 ؎ 12.6%, P ‫؍‬ 0.008), and expression of CD25 (؊24.6 ؎ 11.7%, P F 0.001) and CD69 (؊25.7 ؎ 9.0%, P F 0.001). Then, to identify which of the three G i was involved, G i1 , G i2 , and G i3 proteins were specifically inactivated by stably transfecting dominant-negative mutated forms of their ␣ subunit in Jurkat cells. After activation, IL-2 production and CD69 expression were inhibited only in cells expressing inactive G i2 . We then studied the effects of interleukin-8 (IL-8), a CXC-chemokine with receptors coupled to G i2 and produced in an autocrine fashion by activated T cells. Although its effects varied among donors, exogenous IL-8 stimulated proliferation and CD25 expression (up to, respectively, 200 and 77%) of PB T lymphocytes in response to CD3 activation, in a PT-sensitive manner. IL-8 also stimulated IL-2 production (by up to 42%) and CD69 expression, although weakly (؉27%). Anti-human IL-8 antibody inhibited proliferation (؊43%) and CD25 up-regulation (؊45%) of activated T lymphocytes. In summary, several major responses of human T lymphocytes to TCRmediated activation are regulated by G i2 proteins, which for this function can be activated by IL-8 in an autocrine manner. J. Leukoc. Biol. 67: 742-748; 2000.

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“…Although it is possible that differences in the basic mechanisms which control vesicle formation and consumption in yeast and mammalian cells might be minor, we expect that in mammals additional mechanisms may exist which couple secretion to signal transduction and perhaps provide different cell types with a more specialized repertoire of control mechanisms. For example, recent pharmacological evidence suggests the involvement of heterotrimeric GTP-binding proteins in the secretory pathway of mammalian cells (Donaldson et al, 1991;Stow et al, 1991;Ktistakis et al, 1992), something not reported in yeast. In addition, because in mammalian cells the morphology of the secretory organelles is better visualized and described, questions involving organelle identity and biogenesis may be more easily answered there.…”

Section: Isolation Of Cho Cells With Defects In Secretionmentioning

confidence: 99%

A fluorescent lipid analogue can be used to monitor secretory activity and for isolation of mammalian secretion mutants.

Ktistakis

Kao

Wang

et al. 1995

MBoC

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The use of reporter proteins to study the regulation of secretion has often been complicated by posttranslational processing events that influence the secretion of certain proteins, but are not part of the cellular mechanisms that specifically regulate secretion. This has been a particular limitation for the isolation of mammalian secretion mutants, which has typically been a slow process. To provide a reporter of secretory activity independent of protein processing events, cells were labeled with the fluorescent lipid analogue C5-DMB-ceramide (ceramide coupled to the fluorophore boron dipyrromethene difluoride) and its secretion was followed by fluorescence microscopy and fluorescenceactivated cell sorting. Brefeldin A, which severely inhibits secretion in Chinese hamster ovary cells, blocked secretion of C5-DMB-ceramide. At high temperature, export of C5-DMB-ceramide was inhibited in HRP-1 cells, which have a conditional defect in secretion. Using C5-DMB-ceramide as a reporter of secretory activity, several different pulse-chase protocols were designed that selected mutant Chinese hamster ovary cells that were resistant to the drug brefeldin A and others that were defective in the transport of glycoproteins to the cell surface. Mutant cells of either type were identified in a mutagenized population at a frequency of 10-6. Thus, the fluorescent lipid C5-DMBceramide can be used as a specific marker of secretory activity, providing an efficient, general approach for isolating mammalian cells with defects in the secretory pathway.

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A heterotrimeric G protein, Gα1−3, on Golgi membranes regulates the secretion of heparan sulfate proteoglycan in LLC-PK1 epithelial cells

Cited by 60 publications

References 4 publications

Role of heterotrimeric G proteins in membrane traffic.

Role of heterotrimeric G proteins in membrane traffic.

Positive regulation of human T cell activation by Gi2 proteins and interleukin-8

A fluorescent lipid analogue can be used to monitor secretory activity and for isolation of mammalian secretion mutants.

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