Epstein–Barr virus latent membrane protein 1 mediates serine 25 phosphorylation and nuclear entry of annexin A2 via PI‐PLC–PKCα/PKCβ pathway

Abstract

We have previously elucidated that Epstein-Barr-virus-encoded latent membrane protein 1 (LMP1) can increase the serine phosphorylation level of annexin A2 by activating the protein kinase C (PKC) signaling pathway and that LMP1 induces the nuclear entry of annexin A2 in an energy- and temperature-dependent manner. Here, we further confirm that LMP1 increases the serine phosphorylation level of annexin A2 by activating the phosphoinositide-specific phospholipase C (PI-PLC)-PKC alpha/PKC beta pathway, mainly through the activation of the PKCbeta pathway. Additionally, active recombinant PKC alpha, PKC beta I, and PKC beta II kinases are able to phosphorylate annexin A2 in vitro. Annexin A2 in the nucleus plays an important role in DNA synthesis and cell proliferation. By site-specific substitution of glutamic acid in the place of serine 11 and 25 in the N-terminus, we show that serine 25 phosphorylation of annexin A2 was associated with the nuclear entry of annexin A2, DNA synthesis and cell proliferation, whereas serine 11 has no obvious influence. We demonstrate for the first time that the PI-PLC-PKCalpha/PKCbeta pathway plays an important role in serine phosphorylation and in the nuclear entry of annexin A2 mediated by LMP1. In addition, we show that annexin A2 is the substrate protein of PKC alpha, PKC betaI, and PKC betaII kinases. Serine 25 phosphorylation of annexin A2 is shown to be associated with its nuclear entry, DNA synthesis, and cell proliferation.

Epstein-Barr Virus LMP1 Activates EGFR, STAT3, and ERK through Effects on PKCδ

“…These findings were confirmed using a PKC␦ DN. LMP1 has not been previously shown to activate PKC␦-dependent signaling pathways, although it does regulate Annexin 2 and Ezrin through PKC␣/␤ (8,27). In addition to blocking serine phosphorylation of STAT3, rottlerin and PKC␦ also decreased expression of Bcl-3.…”

Kaposi's Sarcoma-Associated Herpesvirus Latency-Associated Nuclear Antigen and Angiogenin Interact with Common Host Proteins, Including Annexin A2, Which Is Essential for Survival of Latently Infected Cells

“…In EBV-infected cells, EBV latent membrane protein 1 (LMP 1) has been shown to mediate the phosphorylation and nuclear translocation of annexin A2 by activating a PKC pathway where it mediates DNA synthesis and cell proliferation (74,115). We have shown that KSHV-induced ANG activates PLC-␥ and AKT phosphorylation.…”

“…Treatment with neomycin, PLC-␥ inhibitor U73122, or silencing ANG resulted in cell death, inhibition of latent ORF73 (LANA-1) gene expression, and an increase in lytic switch ORF50 (RTA) gene expression (95). Nuclear translocation of annexin A2 was also shown to be inhibited by the PLC-specific inhibitor U73122 (74). Therefore, the decrease in KSHV-infected cell survival, LANA-1 expression, and KSHV latency upon neomycin treatment could be due to cumulative inhibition of both ANG and annexin A2 nuclear delivery.…”

Interferon‐γ stimulates p11‐dependent surface expression of annexin A2 in lung epithelial cells to enhance phagocytosis

“…Annexin A2 has multiple biological functions depending on its localization in the cell. For example, nuclear entry of annexin A2 is associated with DNA synthesis and cell proliferation (Luo et al, 2008). Annexin A2 in the cytosol or localized on organelle membranes plays roles in endocytosis, exocytosis, cytoskeletal rearrangement, or intracellular signal transduction (Hayes et al, 2006;Lorusso et al, 2006;Morel and Gruenberg, 2009;Das et al, 2010).…”