Table 3 Functions of KSHV viral proteins
Latent phase proteins | Functions |
|---|---|
LANA 1,2 | Establish and maintain the latency in KSHV infected cells, bind directly to p53 and pRb [148]. |
Kaposin A, B | Induce the expression of growth factor receptors, possible transformation activity [151]. |
vcyclin | Forms a complex with CDK-6 to inactivate the Rb protein, promoting cell cycle progression and proliferation [152]. Induces apoptosis independent of p53 [153]. |
vFLIP | Blocks caspase 8 activation [154], potent activator of NFκB [154]. |
Lytic phase proteins | Â |
ORF50 (RTA) | Regulates the lytic replication [155]. |
K1 | Activator of the molecules that mimic signaling via the B cell antigen receptor [156]. |
K8 | Regulates lytic-cycle DNA replication [157]. |
K3, K5 | Mediate the down regulation of several immunomodulatory proteins, including CD86, intercellular adhesion molecule 1 (ICAM-1; CD54), and IFN-R [158]. |
vIL-6 | Induces angiogenesis and tumorigenesis by regulating PI3K/PTEN/AKT/GSK-3β signaling pathway [159]. |
vIRF-1 | Binds and inhibits pro-death activities of proteins Bid and Bim [160]. |
vMIPs | Binds to chemokine receptors and induce angiogenesis [161]. |
vGPCR | Transformation activity; promotes the secretion the growth factors, such as VEGF, bFGF, IL-8, and IL-6 [162]. |
vBcl-2 | Inhibits apoptosis [163]. |