Role of Host Cell p 32 in Herpes Simplex Virus 1 De - envelopment During Viral Nuclear

32 To clarify the function(s) of the herpes simplex virus 1 (HSV-1) major virion 33 structural protein UL47 (also designated VP13/14), we screened cells overexpressing UL47 34 for UL47-binding cellular proteins. Tandem affinity purification of transiently expressed 35 UL47 coupled with mass spectrometry-based proteomics technology and subsequent analyses 36 showed that UL47 interacted with cell protein p32 in HSV-1-infected cells. Unlike in 37 mock-infected cells, p32 accumulated at the nuclear rim in HSV-1-infected cells and this p32 38 recruitment to the nuclear rim required UL47. p32 formed a complex(es) with HSV-1 39 proteins UL31, UL34, Us3, UL47 and/or ICP22 in HSV-1-infected cells. All these HSV-1 40 proteins were previously reported to be important for HSV-1 nuclear egress, in which 41 nucleocapsids bud through the inner nuclear membrane (primary envelopment) and the 42 enveloped nucleocapsids then fuse with the outer nuclear membrane (de-envelopment). 43 Like viral proteins UL31, UL34, Us3 and UL47, p32 was detected in primary enveloped 44 virions. p32 knock-down reduced viral replication and induced membranous invaginations 45 adjacent to the nuclear rim containing primary enveloped virions and aberrant localization of 46 UL31 and UL34 in punctate structures at the nuclear rim. These effects of p32 knock-down 47 were reduced in the absence of UL47. Therefore, the effects of p32 knock-down in HSV-1 48 nuclear egress were similar to those of the previously reported mutation(s) in HSV-1 49 regulatory proteins for HSV-1 de-envelopment during viral nuclear egress. Collectively, 50 these results suggested that p32 regulated HSV-1 de-envelopment and replication, in a 51 UL47-dependent manner. 52 53 on Jne 7, 2017 by gest http/jvi.asm .rg/ D ow nladed fom