Role of the UL47p32 interaction in the transmission of Marek's disease virus

Inter-individual transmission is an essential part of viruses' life cycle, yet the molecular basis for transmission remains elusive. Using Marek's Disease Virus (MDV), a deadly and contagious herpesvirus of chickens that is transmitted by inhalation of contaminated dander, we previously demonstrated that tegument protein pUL47 is necessary for horizontal transmission in the natural host while being dispensable for pathogenesis and replication. We showed that pUL47 is also necessary for the correct splicing and expression of UL44 transcripts, which encode glycoprotein gC, another viral protein known as essential for MDV's transmission. Here, with the aim of characterizing the molecular basis for the role of pUL47 in transmission, we identified the cellular protein p32/C1QBP, a regulator of mRNA splicing, as a binding partner. We demonstrate that this interaction is necessary for transmission while being dispensable for the correct splicing of UL44 transcripts and the expression of gC, thus uncoupling the role of pUL47 in transmission from gC. These results provide a deeper molecular understanding of the natural transmission of a Herpesvirus and they suggest that pUL47 may contribute to reprogramming cellular splicing to promote transmission.