Yadav S, Libotte F, Buono E, Valia S, Farina G A, Faggioni A, Farina A
Dep. Experimental Medicine University of Rome "La Sapienza", Italy.
Dep. Molecular Medicine University of Rome "La Sapienza", Italy.
Virus Res. 2017 Mar 15;232:113-122. doi: 10.1016/j.virusres.2017.02.010. Epub 2017 Feb 24.
The nuclear envelope (NE), a structural element of fundamental importance for the cell, is the first barrier that meets a virus in the early stages of viral maturation. Therefore, in order to allow the passage of nucleocapsids, viruses are known to modulate the architecture of the nuclear membrane to permit a proficient viral infection. Epstein-Barr Virus (EBV), a pathogen from Herpesvirus family, possesses two well conserved proteins, BFRF1 and BFLF2, which together form the heterodimeric nuclear egress complex (NEC) that is involved in the early steps of nuclear egress. Here we show that EBV replication causes the delocalization of emerin, a cellular LEM-domain protein normally distributed on the nuclear rim. We also demonstrate that the early lytic protein BFRF1 is responsible for emerin delocalization. Expression of BFRF1 alone or in combination with BFLF2 induces emerin hyperphosphorylation. Altogether, these results suggest a novel mechanism by which EBV exploits the cellular machinery for nucleocapsid egress.
核膜（NE）是细胞的一种具有根本重要性的结构元件，是病毒成熟早期遇到的第一道屏障。因此，为了使核衣壳能够通过，已知病毒会调节核膜结构以实现高效的病毒感染。爱泼斯坦-巴尔病毒（EBV）是疱疹病毒科的一种病原体，拥有两种高度保守的蛋白质，BFRF1和BFLF2，它们共同形成异二聚体核输出复合物（NEC），参与核输出的早期步骤。在这里，我们表明EBV复制会导致emerin（一种通常分布在核边缘的细胞LEM结构域蛋白）的定位改变。我们还证明早期裂解蛋白BFRF1负责emerin的定位改变。单独表达BFRF1或与BFLF2联合表达会诱导emerin过度磷酸化。总之，这些结果提示了一种EBV利用细胞机制进行核衣壳输出的新机制。
