DYNAMICS OF HCMV GEN · Localisation, dynamics and regulation of human cytomegalovirus genomes during lytic and quiescent infection
FP6 — Marie Curie Actions (Human Resources and Mobility)
- Duration
- 2005-03-01 → 2006-02-28
- EU contribution
- €40,000
- Participants
- 1
- Scheme
- ERG
Lines connect the coordinator with its partners.
Results in brief
Final Activity Report Summary - DYNAMICS OF HCMV GEN (Localisation, dynamics and regulation of human cytomegalovirus genomes during lytic and quiescent infection)
Human cytomegalovirus (HCMV) is a common human pathogen of considerable clinical interest. The relative locations of active and repressed genes within the nucleus are becoming recognised as a significant factor in the control of gene expression. We have developed systems to visualise parental HCMV amplicon genomes, the replication compartments that develop from those genomes and the association of these structures with PML nuclear bodies (ND10) in live infected cells. Plasmids containing viral replication and packaging signals, a gene expressing Enhanced yellow fluorescent protein (EYFP) linked to the Tetracycline repressor DNA binding domain (TetR) and 14 copies of the Tetracycline operator (TetO) sequence were used to produce amplicon genomes, packaged into otherwise normal viral particles. The frequency of viral genome juxtaposition to ND10 was found to be substantially increased by inclusion of an active HCVM Early gene transcription unit, indicating that the association is neither random nor passive. Furthermore, the ND10 associated genomes preferentially progressed to form viral replication compartments. Thus, active viral transcription contributes to the efficiency of viral genome association with ND10 and this in turn increases the probability that the genome will engage in active DNA replication. These studies in live cells provide novel insight into virus-ND10 interactions and provide compelling visualisation of their functional relevance.
Data: CORDIS, © European Union
Project objective
Human Cytomegalovirus (HCMV) represents the major infectious cause of birth defects, as well as an important pathogen for immuno-compromised individuals. The virus owes its evolutionary success and clinical importance to its ability to establish a latent infection and is able to reactivate, presenting significant clinical problems to immuno-compromised individuals, certain transplant patients and also neonates.The balance between the lyric and latent status is controlled by both host and viral factors and among them, the HCMV immediate early protein IE1. Viruses, which fail to express functional IE1 enter the lytic cycle inefficiently and instead can be maintained in a quiescent state in the cell. Upon HCMV infection, distinct nuclear domains known as ND10 are disrupted at early times and the regulatory protein IE1 is necessary and sufficient for this effect. It has been proposed that IE1 potentially play a role in maintenance of the latent state of HCMV DNA and that its activity might be involved in viral gene expression or repression pathways. Considering that the environment of parental viral genomes in the nucleus and their interactions with viral and cellular proteins are important in transcriptional activation or silencing, it is particularly interesting t hat several HCMV transcripts are preferentially found in association with ND10 and a number of ND10 proteins or proteins with which they interact, have been implicated in repression.The proposed project intends to investigate the localisation and dynamics of lytic and quiescent viral genomes in the cell and explore the involvement of IE1 in the molecular and cellular events that take place during reactivation of HCMV gene expression. Parental HCMV genomes will be visualised by using engineered HCMV amplicon plasmids, taking the advantage of auto-fluorescent fusion proteins along with the specific Tetracycline Repressor/Operator interaction
Original text from CORDIS.
Participants
- UNIVERSITY OF CRETE · POROS IRAKLEIOU KRITISCoordinatorGreece
Links
Data: CORDIS, © European Union