@article {712,
	title = {Association of caveolin with Chlamydia trachomatis inclusions at early and late stages of infection.},
	journal = {Exp Cell Res},
	volume = {266},
	year = {2001},
	month = {2001 Jun 10},
	pages = {229-38},
	abstract = {The mechanism by which the intracellular bacterial pathogen Chlamydia trachomatis enters eukaryotic cells is poorly understood. There are conflicting reports of entry occurring by clathrin-dependent and clathrin-independent processes. We report here that C. trachomatis serovar K enters HEp-2 and HeLa 229 epithelial cells and J-774A.1 mouse macrophage/monocyte cells via caveolin-containing sphingolipid and cholesterol-enriched raft microdomains in the host cell plasma membranes. First, filipin and nystatin, drugs that specifically disrupt raft function by cholesterol chelation, each impaired entry of C. trachomatis serovar K. In control experiments, filipin did not impair entry of the same organism by an antibody-mediated opsonic process, nor did it impair entry of BSA-coated microspheres. Second, the chlamydia-containing endocytic vesicles specifically reacted with antisera against the caveolae marker protein caveolin. These vesicles are known to become the inclusions in which parasite replication occurs. They avoid fusion with lysosomes and instead traffic to the Golgi region, where they intercept Golgi-derived vesicles that recycle sphingolipids and cholesterol to the plasma membrane. We also report that late-stage C. trachomatis inclusions continue to display high levels of caveolin, which they likely acquire from the exocytic Golgi vesicles. We suggest that the atypical raft-mediated entry process may have important consequences for the host-pathogen interaction well after entry has occurred. These consequences include enabling the chlamydial vesicle to avoid acidification and fusion with lysosomes, to traffic to the Golgi region, and to intercept sphingolipid-containing vesicles from the Golgi.},
	keywords = {Animals, Caveolin 1, Caveolins, Cell Line, Chlamydia trachomatis, Epithelium, Filipin, HeLa Cells, Humans, Inclusion Bodies, Macrophages, Membrane Microdomains, Mice, Nystatin, Phagosomes},
	issn = {0014-4827},
	doi = {10.1006/excr.2001.5202},
	author = {Norkin, L C and Wolfrom, S A and Stuart, E S}
}
@article {710,
	title = {Extracellular simian virus 40 transmits a signal that promotes virus enclosure within caveolae.},
	journal = {Exp Cell Res},
	volume = {246},
	year = {1999},
	month = {1999 Jan 10},
	pages = {83-90},
	abstract = {It was reported earlier that entry of simian virus 40 (SV40) into cells is promoted by a signal transmitted by the virus from the cell surface and that SV40 enters cells through caveolae. It is shown here that bound SV40 begins to partition into a caveolae-enriched Triton X-100-insoluble membrane fraction at 30 min postadsorption. Maximal levels of SV40 were seen in that fraction at 1 h. The sterol-binding agent nystatin, which selectively disrupts the cholesterol-enriched caveolae-containing membrane microdomain, selectively blocked the SV40-induced signal. This implies that the SV40 signal is transmitted from that membrane microdomain. The tyrosine kinase inhibitor genistein, which was earlier shown to block the SV40-induced signal and infectious entry, did not block the partitioning of SV40 into the detergent-insoluble membrane fraction. This shows that the signal is not required for the translocation of SV40 to the detergent-insoluble membrane and is consistent with the finding that the signal is likely transmitted from that membrane microdomain. However, electron microscopy of the Triton X-100-insoluble membrane fraction showed that genistein caused SV40 particles to accumulate at the annuli or mouths of the caveolae. In contrast, most SV40 particles were found enclosed within caveolae in parallel samples from untreated control cells. Together, these results imply that SV40 initially binds to flat detergent-soluble membrane. The virus then translocates to a caveolae-containing detergent-insoluble membrane microdomain. From the flat portion of that membrane microdomain the virus induces a signal which promotes its entry into caveolae.},
	keywords = {Animals, Blotting, Northern, Blotting, Western, Caveolin 1, Caveolins, Cell Line, Cell Membrane, Cercopithecus aethiops, Cholesterol, Endocytosis, Genes, myc, Genistein, Kidney, Membrane Proteins, Microscopy, Electron, Nystatin, Octoxynol, Signal Transduction, Simian virus 40, Solubility},
	issn = {0014-4827},
	doi = {10.1006/excr.1998.4301},
	author = {Chen, Y and Norkin, L C}
}
@article {709,
	title = {MHC class I molecules are enriched in caveolae but do not enter with simian virus 40.},
	journal = {J Gen Virol},
	volume = {79 ( Pt 6)},
	year = {1998},
	month = {1998 Jun},
	pages = {1469-77},
	abstract = {Simian virus 40 (SV40) binds to MHC class I molecules anywhere on the cell surface and then enters through caveolae. The fate of class I molecules after SV40 binding is not known. Sensitivity of 125I-surface-labelled class I molecules to papain cleavage was used to distinguish internalized class I molecules from class I molecules remaining at the cell surface. Whereas the caveolae-enriched membrane microdomain was found to also be enriched for class I molecules, no internalized papain-resistant 125I-surface-labelled class I molecules could be detected at any time in either control cells or in cells preadsorbed with saturating amounts of SV40. Instead, 125I-surface-labelled class I molecules, as well as preadsorbed 125I-labelled anti-class I antibodies, accumulated in the medium, coincident with the turnover of class I molecules at the cell surface. The class I heavy chains that accumulated in the medium were truncated and their release was specifically prevented by the metalloprotease inhibitor 1,10-phenanthroline. Thus, whereas class I molecules mediate SV40 binding, they do not appear to mediate SV40 entry.},
	keywords = {Animals, Caveolin 1, Caveolins, Cell Line, Cell Membrane, Cercopithecus aethiops, Histocompatibility Antigens Class I, Humans, Membrane Proteins, Simian virus 40},
	issn = {0022-1317},
	author = {Anderson, H A and Chen, Y and Norkin, L C}
}
@article {708,
	title = {Bound simian virus 40 translocates to caveolin-enriched membrane domains, and its entry is inhibited by drugs that selectively disrupt caveolae.},
	journal = {Mol Biol Cell},
	volume = {7},
	year = {1996},
	month = {1996 Nov},
	pages = {1825-34},
	abstract = {Simian virus 40 (SV40) entry leading to infection occurred only after the virus was at the cell surface for 1.5 to 2 h. SV40 infectious entry was not sensitive to cytosol acidification, a treatment that blocks endocytosis via clathrin-coated vesicles. Instead, SV40 infectious entry was blocked by treating cells with the phorbol ester PMA or nystatin, which selectively disrupts caveolae. In control experiments, transferrin internalization was sensitive to cytosol acidification but was not sensitive to PMA or nystatin. Also, absorbed transferrin entered cells within minutes. Finally, bound SV40 translocated to caveolin-enriched membrane complexes isolated by a Triton X-100 insolubility protocol. Treatment with nystatin did not impair SV40 binding but did block the partitioning of virus into the caveolin-enriched complexes.},
	keywords = {Animals, Antigens, Polyomavirus Transforming, Caveolin 1, Caveolins, Cell Line, Cell Membrane, Coated Vesicles, Endocytosis, Membrane Proteins, Nystatin, Organelles, Simian virus 40, Tetradecanoylphorbol Acetate},
	issn = {1059-1524},
	author = {Anderson, H A and Chen, Y and Norkin, L C}
}
@article {707,
	title = {Extracellular simian virus 40 induces an ERK/MAP kinase-independent signalling pathway that activates primary response genes and promotes virus entry.},
	journal = {J Gen Virol},
	volume = {77 ( Pt 9)},
	year = {1996},
	month = {1996 Sep},
	pages = {2173-82},
	abstract = {Simian virus 40 (SV40) binding to growth-arrested cells activated an intracellular signalling pathway that induced the up-regulation of the primary response genes c-myc, c-jun and c-sis within 30 min and of JE within 90 min. The up-regulation of the primary response genes occurred in the presence of cycloheximide and when UV-inactivated SV40 was adsorbed to cells. SV40 binding did not activate Raf or mitogen-activated protein kinase (MAP/ERK1), or mobilize intracellular Ca2+. The SV40-induced up-regulation of c-myc and c-jun was blocked by the tyrosine kinase inhibitor, genistein, and by the protein kinase C (PKC) inhibitor, calphostin C, but not by expression of the MAP kinase-specific phosphatase, MKP-1. These results suggest that the SV40-induced signalling pathway includes the activities of a tyrosine kinase and a Ca(2+)-independent isoform of PKC, but not of Raf or MAP kinase. Finally, SV40 infectious entry into cells was specifically and reversibly blocked by genistein.},
	keywords = {Animals, Calcium, Calcium-Calmodulin-Dependent Protein Kinases, Cell Cycle Proteins, Cell Line, Cercopithecus aethiops, Dual Specificity Phosphatase 1, Enzyme Inhibitors, Gene Expression Regulation, Viral, Genistein, Humans, Immediate-Early Proteins, Isoflavones, Mitogen-Activated Protein Kinase 3, Mitogen-Activated Protein Kinases, Naphthalenes, Phosphoprotein Phosphatases, Platelet-Derived Growth Factor, Protein Kinase C, Protein Phosphatase 1, Protein Tyrosine Phosphatases, Protein-Serine-Threonine Kinases, Proto-Oncogene Proteins, Proto-Oncogene Proteins c-jun, Proto-Oncogene Proteins c-myc, Proto-Oncogene Proteins c-raf, Proto-Oncogene Proteins c-sis, Signal Transduction, Simian virus 40, Up-Regulation},
	issn = {0022-1317},
	author = {Dangoria, N S and Breau, W C and Anderson, H A and Cishek, D M and Norkin, L C}
}
@article {703,
	title = {Class I major histocompatibility proteins are an essential component of the simian virus 40 receptor.},
	journal = {J Virol},
	volume = {66},
	year = {1992},
	month = {1992 Apr},
	pages = {2037-45},
	abstract = {The class I molecules encoded by the major histocompatibility complex (MHC) present endogenously synthesized antigenic peptide fragments to cytotoxic T lymphocytes. We show here that these proteins are an essential component of the cell surface receptor for simian virus 40 (SV40). First, SV40 binding to cells can be blocked by two monoclonal antibodies against class I human lymphocyte antigen (HLA) proteins but not by monoclonal antibodies specific for other cell surface proteins. Second, SV40 does not bind to cells of two different human lymphoblastoid cell lines which do not express surface class I MHC proteins because of genetic defects in the beta 2-microglobulin gene in one line and in the HLA complex in the other. Transfection of these cell lines with cloned genes for beta 2-microglobulin and HLA-B8, respectively, restored expression of their surface class I MHC proteins and resulted in concomitant SV40 binding. Finally, SV40 binds to purified HLA proteins in vitro and selectively binds to class I MHC proteins in a cell surface extract.},
	keywords = {Animals, Binding, Competitive, Blotting, Western, Cell Line, Flow Cytometry, Histocompatibility Antigens Class I, Humans, Precipitin Tests, Receptors, Virus, Simian virus 40, Transfection},
	issn = {0022-538X},
	author = {Breau, W C and Atwood, W J and Norkin, L C}
}
