Plays an essential role in virion nuclear egress, the first step of virion release from infected cell. Within the host nucleus, NEC1 interacts with the newly formed capsid through the vertexes and directs it to the inner nuclear membrane by associating with NEC2. Induces the budding of the capsid at the inner nuclear membrane as well as its envelopment into the perinuclear space. There, the NEC1/NEC2 complex promotes the fusion of the enveloped capsid with the outer nuclear membrane and the subsequent release of the viral capsid into the cytoplasm where it will reach the secondary budding sites in the host Golgi or trans-Golgi network. Forms a heterohexameric complex with NEC1. Localizes also at the transient membrane of perinuclear virions. Phosphorylated (By similarity). Phosphorylation by viral kinase UL97 at Ser-216 plays an important role for correct viral nuclear egress complex (NEC) localization (By similarity). Belongs to the herpesviridae NEC2 protein family.