Details

Autor(en) / Beteiligte

• Bier, K

Titel

Identification of Viral and Host Factors Involved in the Assembly, Processing and Nuclear Export of Influenza a Viral mRNPs

Ort / Verlag

ProQuest Dissertations & Theses

Erscheinungsjahr

2010

Quelle

ProQuest Dissertations & Theses A&I

Beschreibungen/Notizen

• While it is known that the virus hijacks cellular mechanisms during infection, little is known about the specific factors and mechanisms involved in influenza A viral mRNP processing and nuclear export. There are three different types of viral mRNA (intronless, intron-containing unspliced and spliced), which suggests that more than one mechanism for assembly and export might operate in influenza virus-infected cells. Viral and host factors involved in these mechanisms were identified and investigated using two different approaches. In the first approach, proteins known to be involved in cellular mRNA processing and export were investigated. It was demonstrated that the viral polymerase complex does not associate with viral mRNA. Therefore, it is unlikely to play a role in the protection of viral mRNA from endonucleolytic degradation and the regulation of the alternative splicing of the viral M1 mRNA as postulated by previous studies. Viral NS1 protein was found to interact with viral mRNA and it was shown to upregulate viral mRNA levels in ribonucleoprotein reconstitution assays. Host factors Aly, eIF4A3, NXF1 and PABP1 were also found to interact with viral mRNA, and it was shown that NXF1 and eIF4A3 are required for efficient viral growth. In the second approach, a viral mRNA was tagged to allow its affinity purification and the identification of factors that associate with it using mass spectrometry. A recombinant virus with the tag inserted stably in its genome was successfully rescued. One host factor (EEF2) and several viral factors (NS1, NP, M1 and HA) were identified as interacting with viral mRNA using this approach.