Kaposi's Sarcoma-Associated Herpesvirus Modulates Microtubule Dynamics via RhoA-GTP-Diaphanous 2 Signaling and Utilizes the Dynein Motors To Deliver Its DNA to the Nucleus

Journal of Virology - Tập 79 Số 2 - Trang 1191-1206 - 2005
Pramod P. Naranatt1, Harinivas H. Krishnan1, Marilyn S. Smith1, Bala Chandran1
1Department of Microbiology, Molecular Genetics and Immunology, The University of Kansas Medical Center, Kansas City, Kansas

Tóm tắt

ABSTRACT Human herpesvirus 8 (HHV-8; also called Kaposi's sarcoma-associated herpesvirus), which is implicated in the pathogenesis of Kaposi's sarcoma (KS) and lymphoproliferative disorders, infects a variety of target cells both in vivo and in vitro. HHV-8 binds to several in vitro target cells via cell surface heparan sulfate and utilizes the α3β1 integrin as one of its entry receptors. Interactions with cell surface molecules induce the activation of host cell signaling cascades and cytoskeletal changes (P. P. Naranatt, S. M. Akula, C. A. Zien, H. H. Krishnan, and B. Chandran, J. Virol. 77: 1524-1539, 2003). However, the mechanism by which the HHV-8-induced signaling pathway facilitates the complex events associated with the internalization and nuclear trafficking of internalized viral DNA is as yet undefined. Here we examined the role of HHV-8-induced cytoskeletal dynamics in the infectious process and their interlinkage with signaling pathways. The depolymerization of microtubules did not affect HHV-8 binding and internalization, but it inhibited the nuclear delivery of viral DNA and infection. In contrast, the depolymerization of actin microfilaments did not have any effect on virus binding, entry, nuclear delivery, or infection. Early during infection, HHV-8 induced the acetylation of microtubules and the activation of the RhoA and Rac1 GTPases. The inactivation of Rho GTPases by Clostridium difficile toxin B significantly reduced microtubular acetylation and the delivery of viral DNA to the nucleus. In contrast, the activation of Rho GTPases by Escherichia coli cytotoxic necrotizing factor significantly augmented the nuclear delivery of viral DNA. Among the Rho GTPase-induced downstream effector molecules known to stabilize the microtubules, the activation of RhoA-GTP-dependent diaphanous 2 was observed, with no significant activation in the Rac- and Cdc42-dependent PAK1/2 and stathmin molecules. The nuclear delivery of viral DNA increased in cells expressing a constitutively active RhoA mutant and decreased in cells expressing a dominant-negative mutant of RhoA. HHV-8 capsids colocalized with the microtubules, as observed by confocal microscopic examination, and the colocalization was abolished by the destabilization of microtubules with nocodazole and by the phosphatidylinositol 3-kinase inhibitor affecting the Rho GTPases. These results suggest that HHV-8 induces Rho GTPases, and in doing so, modulates microtubules and promotes the trafficking of viral capsids and the establishment of infection. This is the first demonstration of virus-induced host cell signaling pathways in the modulation of microtubule dynamics and in the trafficking of viral DNA to the infected cell nucleus. These results further support our hypothesis that HHV-8 manipulates the host cell signaling pathway to create an appropriate intracellular environment that is conducive to the establishment of a successful infection.

Từ khóa


Tài liệu tham khảo

Aktories, K., G. Schmidt, and I. Just. 2000. Rho GTPases as targets of bacterial protein toxins. J. Biol. Chem.381:421-426.

10.1016/S0966-842X(03)00042-8

10.1006/viro.2000.0851

10.1006/viro.2001.0921

10.1016/S0092-8674(02)00628-1

10.1128/JVI.77.14.7978-7990.2003

10.1128/JVI.75.20.9819-9827.2001

10.1083/jcb.123.6.1373

10.1056/NEJM200004063421407

10.1034/j.1600-0854.2001.020301.x

10.1128/JVI.77.11.6474-6481.2003

10.1074/jbc.271.7.3756

10.1042/bj3480241

10.1016/S0169-409X(03)00049-8

10.1099/0022-1317-80-1-147

10.1126/science.7997879

10.1006/viro.1993.1585

10.1074/jbc.274.16.11046

10.1016/S0021-9258(17)42302-7

10.1126/science.7716514

10.1016/0092-8674(81)90072-6

10.1083/jcb.141.1.175

10.1242/jcs.109.7.1739

10.1016/S0092-8674(01)00392-0

10.1016/0042-6822(73)90050-0

10.1016/S0014-4827(03)00253-2

10.1074/jbc.C000635200

10.1091/mbc.01-07-0348

10.1146/annurev.cellbio.14.1.137

10.1083/jcb.132.4.617

10.1128/JVI.72.8.6448-6455.1998

10.1242/jcs.99.2.283

10.1016/S0092-8674(02)00800-0

10.1128/JVI.77.4.2615-2622.2003

10.1016/S0955-0674(97)80147-0

10.1128/JVI.77.14.8147-8152.2003

10.1038/35050598

10.1128/JVI.74.1.474-482.2000

10.1083/jcb.142.1.181

10.1046/j.1462-5822.2001.00091.x

10.1016/S0167-4889(00)00009-4

10.1128/jvi.71.10.7145-7156.1997

10.1128/JVI.78.7.3601-3620.2004

10.1099/0022-1317-67-9-2023

10.1128/JVI.77.7.4291-4297.2003

10.1016/0955-0674(95)80047-6

10.1083/jcb.200203150

10.1158/0008-5472.CAN-03-2767

10.1007/s00705-002-0813-7

10.1128/JVI.77.2.1524-1539.2003

10.1006/viro.2000.0468

10.1016/0092-8674(95)90370-4

10.1038/35087035

10.1126/science.1069784

10.1083/jcb.104.2.289

10.1042/bj20030139

10.1128/JVI.72.6.5182-5188.1998

Schulz T. F. Y. Chang and P. S. Moore. 1998. Kaposi's sarcoma-associated herpesvirus (human herpesvirus 8) p. 87-134. In D. J. McCance (ed.) Human tumor viruses. American Society for Microbiology Washington D.C.

10.1083/jcb.138.1.131

10.1128/JVI.78.8.4207-4223.2004

10.1099/0022-1317-83-7-1535

10.1016/S0966-842X(00)01824-2

Stidwell, R. P., and U. F. Greber. 2000. Intracellular virus trafficking reveals physiological characteristics of cytoskeleton. News Physiol. Sci.15:67-71.

10.1083/jcb.144.4.657

10.1093/emboj/20.6.1310

10.1128/JVI.75.3.1378-1386.2001

10.1128/JVI.75.16.7517-7527.2001

10.1038/9018

10.1146/annurev.cellbio.16.1.627

10.1128/JVI.74.3.1355-1363.2000

Thông tin
Thông tin xuất bản

Journal of Virology

Tập 79 Số 2

1191-1206

Thông tin tác giả