Gangliosides That Associate with Lipid Rafts Mediate Transport of Cholera and Related Toxins from the Plasma Membrane to Endoplasmic Reticulm

Fujinaga, Yukako; Wolf, Anne; Rodighiero, Chiara; Wheeler, Heidi E.; Tsai, Billy; Allen, Larry A.; Jobling, Michael G.; Rapoport, Tom A.; Holmes, Randall K.; Lencer, Wayne I.

doi:10.1091/mbc.e03-06-0354

Cited by 216 publications

(243 citation statements)

References 47 publications

Supporting

Mentioning

230

Contrasting

Unclassified

Order By: Relevance

“…CTB is internalized in a lipid-raft-dependent manner after binding to its receptor GM1 ganglioside (Fujinaga et al, 2003). CTB internalization was blocked when RAW264.7 cells were treated with MbCD, confirming that lipid-raft-dependent endocytosis was inhibited (Fig.…”

Section: Depletion Of Cellular Cholesterol Inhibits Mnv-1 Endocytosismentioning

confidence: 55%

Murine norovirus-1 cell entry is mediated through a non-clathrin-, non-caveolae-, dynamin- and cholesterol-dependent pathway

Gerondopoulos

Jackson

Monaghan

et al. 2010

Journal of General Virology

View full text Add to dashboard Cite

For many viruses, endocytosis and exposure to the low pH within acidic endosomes is essential for infection. It has previously been reported that feline calicivirus uses clathrin-mediated endocytosis for entry into mammalian cells. Here, we report that infection of RAW264.7 macrophages by the closely related murine norovirus-1 (MNV-1) does not require the clathrin pathway, as infection was not inhibited by expression of dominant-negative Eps15 or by knockdown of the adaptin-2 complex. Further, infection was not inhibited by reagents that raise endosomal pH. RAW264.7 macrophages were shown not to express caveolin, and flotillin depletion did not inhibit infection, suggesting that caveolae and the flotillin pathway are not required for cell entry. However, MNV-1 infection was inhibited by methyl-b-cyclodextrin and the dynamin inhibitor, dynasore. Addition of these drugs to the cells after a period of virus internalization did not inhibit infection, suggesting the involvement of cholesterol-sensitive lipid rafts and dynamin in the entry mechanism. Macropinocytosis (MPC) was shown to be active in RAW264.7 macrophages (as indicated by uptake of dextran) and could be blocked by 5-(N-ethyl-N-isopropyl) amiloride (EIPA), which is reported to inhibit this pathway. However, infection was enhanced in the presence of EIPA. Similarly, actin disruption, which also inhibits MPC, resulted in enhanced infection. These results suggest that MPC could contribute to virus degradation or that inhibition of MPC could lead to the upregulation of other endocytic pathways of virus uptake. INTRODUCTIONThe family Caliciviridae is divided into four genera: Vesivirus, Lagovirus, Sapovirus and Norovirus. The human noroviruses are the most common cause of acute viral gastroenteritis, especially in industrialized countries (Lopman et al., 2003); there is currently no treatment or vaccine for these viruses. In addition, there is still no routine tissue culture system for the propagation of human noroviruses, but the recent discovery of murine norovirus-1 (MNV-1) has provided an efficient model system for the study of norovirus replication, as this virus replicates efficiently in murine macrophages and dendritic cells (DCs) (Karst et al., 2003;Wobus et al., 2004). MNV-1 is highly prevalent in laboratory mice and has been shown to be lethal to mice with impaired innate immunity (Hsu et al., 2006;Karst et al., 2003;Muller et al., 2007).Noroviruses are non-enveloped and contain a singlestranded RNA genome of about 7.3 kb, which is linked to the viral VPg protein at the 59 end and is polyadenylated at the 39 end (Karst et al., 2003;Wobus et al., 2004). The genome is organized into four open reading frames (ORF-1-4). ORF-1 encodes the non-structural proteins, whereas ORF-2 and ORF-3 encode structural proteins (Sosnovtsev et al., 2006). ORF-4 was recently identified within the MNV-1 genome and encodes a single protein of unknown function (Thackray et al., 2007).For many viruses, infection requires virus uptake by endocytosis. A number of different endo...

show abstract

Section: Depletion Of Cellular Cholesterol Inhibits Mnv-1 Endocytosismentioning

confidence: 55%

Murine norovirus-1 cell entry is mediated through a non-clathrin-, non-caveolae-, dynamin- and cholesterol-dependent pathway

Gerondopoulos

Jackson

Monaghan

et al. 2010

Journal of General Virology

View full text Add to dashboard Cite

show abstract

“…The intracellular transport routes used by VTB can vary between cell types (Falguieres et al, 2001); only lipid-raft-associated Gb 3 , dependent on Gb 3 fatty acid composition , may mediate Golgi/ER retrograde transport leading to cytotoxicity. Gb 3 raft association has been implicated in ER translocation of VTA (Smith et al, 2006) and ER retrograde transport of the cholera toxin B subunit is raft dependent (Fujinaga et al, 2003). However, unlike cholera toxin, VTA contains no ER-targeting motif (Jackson et al, 1999) and depends on VTB association for ER targeting, and hence translocation.…”

Section: Discussionmentioning

confidence: 99%

Membrane cytosolic translocation of verotoxin A1 subunit in target cells

Tam

Lingwood

2007

Microbiology

View full text Add to dashboard Cite

“…Thereby, CT, as well as ST, seems to use a KDEL-receptor-and COPI-independent pathway to gain access to the ER. The KDEL sequence may rather function to efficiently retain the toxins in the ER, allowing the A1 chain to be transported into the cytosol (Johannes et al, 1997;Fujinaga et al, 2003). The A1 fragment is responsible for the enzymatic activities of the toxin, including NAD hydrolysis in ADP-ribose and nicotinamide, and transfer of ADPribose to Arg 187 of the α-subunit of stimulatory protein (G αs ), leading to stimulation of AC and elevated intracellular cAMP (de Haan and Hirst, 2004).…”

Section: Lipid-derivative Receptors and Long Trafficking Pathways Of mentioning

confidence: 99%

Bacterial protein toxins and lipids: role in toxin targeting and activity

Geny

Popoff

2006

Biology of the Cell

View full text Add to dashboard Cite

All bacterial toxins, which globally are hydrophilic proteins, interact first with their target cells by recognizing a surface receptor, which is either a lipid or a lipid derivative, or another compound but in a lipid environment. Intracellular active toxins follow various trafficking pathways, the sorting of which is greatly dependent on the nature of the receptor, notably lipidic receptor or receptor embedded into a distinct environment such as lipid microdomains. Numerous other toxins act locally on cell membrane. Indeed, phospholipase activity is a common mechanism shared by several membrane‐damaging toxins. In addition, many toxins active intracellularly or on cell membrane modulate host cell phospholipid pathways. Unusually, a few bacterial toxins require a lipid post‐translational modification to be active. Thereby, lipids are obligate partners of bacterial toxins.

show abstract

Gangliosides That Associate with Lipid Rafts Mediate Transport of Cholera and Related Toxins from the Plasma Membrane to Endoplasmic Reticulm

Cited by 216 publications

References 47 publications

Murine norovirus-1 cell entry is mediated through a non-clathrin-, non-caveolae-, dynamin- and cholesterol-dependent pathway

Murine norovirus-1 cell entry is mediated through a non-clathrin-, non-caveolae-, dynamin- and cholesterol-dependent pathway

Membrane cytosolic translocation of verotoxin A1 subunit in target cells

Bacterial protein toxins and lipids: role in toxin targeting and activity

Contact Info

Product

Resources

About