KSHV gB associated RGD interactions promote attachment of cells by inhibiting the potential migratory signals induced by the disintegrin-like domain

ECU Author/Contributor (non-ECU co-authors, if there are any, appear on document)

Hosni,Walker,Lia,Akula,Shaw Hussein (Creator)

Institution

East Carolina University (ECU )

Web Site: http://www.ecu.edu/lib/

Abstract: Background: Kaposi"s sarcoma-associated herpesvirus (KSHV) glycoprotein B (gB) is not only expressed on theenvelope of mature virions but also on the surfaces of cells undergoing lytic replication. Among herpesviruses,KSHV gB is the only glycoprotein known to possess the RGD (Arg-Gly-Asp) binding integrin domain critical tomediating cell attachment. Recent studies described gB to also possess a disintegrin-like domain (DLD) said tointeract with non-RGD binding integrins. We wanted to decipher the roles of two individually distinct integrinbinding domains (RGD versus DLD) within KSHV gB in regulating attachment of cells over cell migration.Methods: We established HeLa cells expressing recombinant full length gB, gB lacking a functional RGD (gBΔR),and gB lacking a functionally intact DLD (gBΔD) on their cell surfaces. These cells were tested in wound healingassay, Transwell migration assay, and adhesion assay to monitor the ability of the RGD and DLD integrin recognitionmotifs in gB to mediate migration and attachment of cells. We also used soluble forms of the respective gBrecombinant proteins to analyze and confirm their effect on migration and attachment of cells. The resultsfrom the above studies were authenticated by the use of imaging, and standard biochemical approaches asWestern blotting and RNA silencing using small interfering RNA.Results: The present report provides the following novel findings: (i) gB does not induce cell migration; (ii) RGDdomain in KSHV gB is the switch that inhibits the ability of DLD to induce cellular migration thus promotingattachment of cells.Conclusions: Independently, RGD interactions mediate attachment of cells while DLD interactions regulatemigration of cells. However, when both RGD and DLD are functionally present in the same protein, gB, the RGDinteraction-induced attachment of cells overshadows the ability of DLD mediated signaling to induce migrationof cells. Furthering our understanding of the molecular mechanism of integrin engagement with RGD and DLD motifs within gB could identify promising new therapeutic avenues and research areas to explore

Additional Information

Publication

Other

Language: English

Date: 2016

Keywords

Integrins, Disintegrins, RGD, DLD, KSHV gB, Migration

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