P32 Is a Novel Target for ICP34.5 of Herpes Simplex Virus Type 1, and Facilitates Viral Nuclear Egress [Signal Transduction]

October 29th, 2014 by Wang, Y., Yang, Y., Wu, S., Pan, S., Zhou, C., Ma, Y., Ru, Y., Dong, S., He, B., Zhang, C., Cao, Y.

As a large double-stranded DNA virus, herpes simplex virus type 1 (HSV-1) assembles capsids in the nucleus where the viral particles exit by budding through the inner nuclear membrane. Although a number of viral and host proteins are involved, the machinery of viral egress is not well understood. In search for host interacting proteins of ICP34.5 which is a virulence factor of HSV-1, we identify a cellular protein p32 (gC1qR/HABP1) by Mass-Spectrophotometer analysis. When expressed, ICP34.5 associates with p32 in mammalian cells. Upon HSV-1 infection, p32 is recruited to the inner nuclear membrane by ICP34.5, which parallels with the phosphorylation and rearrangement of nuclear lamina. Knock-down of p32 in HSV-1-infected cells significantly reduces the production of cell-free viruses, suggesting that p32 is a mediator of HSV-1 nuclear egress. These observations suggest that the interaction between HSV-1 ICP34.5 and p32 leads to the disintegration of nuclear lamina and facilitates the nuclear egress of HSV-1 particles.