Kaposi's Sarcoma-Associated Herpesvirus (Human Herpesvirus 8) Open Reading Frame 4 Protein (Kaposica) Is a Functional Homolog of Complement Control Proteins

• DOI: 10.1128/jvi.77.6.3878-3881.2003
• Publication Date: 2003-02-27T23:28:23Z
• Authors: Jayati Mullick; John Bernet; Akhilesh K. Singh; John D. Lambris; Arvind Sahu
• Keywords: Kaposi's sarcoma-associated herpesvirus; Complement control protein

The genome analysis of Kaposi's sarcoma-associated herpesvirus (KSHV) has revealed the presence an open reading frame (ORF 4) with sequence homology to complement control proteins. To assign a function this protein, we have now expressed ORF using Pichia expression system and shown that purified protein inhibited human complement-mediated lysis erythrocytes, blocked cell surface deposition C3b (the proteolytically activated form C3), served as cofactor for factor I-mediated inactivation proteins C4b subunits C3 convertases). Thus, our data indicate KSHV inhibitor activation (kaposica) provides mechanism by which can subvert attack host.