Head-to-tail intramolecular interaction of herpes simplex virus type 1 regulatory protein ICP27 is important for its interaction with cellular mRNA export receptor TAP/NXF1.
Herpes simplex virus type 1 (HSV-1) protein ICP27 has many important functions during infection that are achieved through interactions with a number of cellular proteins. In its role as a viral RNA export protein, ICP27 interacts with TAP/NXF1, the cellular mRNA export receptor, and both the N and C termini of ICP27 must be intact for this interaction to take place. Here we show by bimolecular fluorescence complementation (BiFC) that ICP27 interacts directly with TAP/NXF1 during infection, and this interaction failed to occur with an ICP27 mutant bearing substitutions of serines for cysteines at positions 483 and 488 in the C-terminal zinc finger. Recently, we showed that ICP27 undergoes a head-to-tail intramolecular interaction, which could make the N- and C-terminal regions accessible for binding to TAP/NXF1. To determine the importance of intramolecular association of ICP27 to its interaction with TAP/NXF1, we performed BiFC-based fluorescence resonance energy transfer (FRET) by acceptor photobleaching. BiFC-based FRET showed that the interaction between ICP27 and TAP/NXF1 occurred in living cells upon head-to-tail intramolecular association of ICP27, further establishing that TAP/NXF1 interacts with both the N and C termini of ICP27.
Department of Microbiology and Molecular Genetics, School of Medicine, University of California, Irvine, California, USA.
Felicia P
FP
Hernandez
Rozanne M
RM
Sandri-Goldin
D019943:Amino Acid Substitution / Q000235:genetics; D000818:Animals; D002478:Cells, Cultured; D018259:Herpesvirus 1, Human / Q000502:physiology*; D017874:Immediate-Early Proteins / Q000235:genetics / Q000378:metabolism*; D008856:Microscopy, Fluorescence; D050505:Mutant Proteins / Q000235:genetics / Q000378:metabolism; D029543:Nucleocytoplasmic Transport Proteins / Q000378:metabolism*; D011485:Protein Binding; D054730:Protein Interaction Domains and Motifs; D025941:Protein Interaction Mapping; D016601:RNA-Binding Proteins / Q000378:metabolism*
C057120:ICP27 protein, human herpesvirus 1; D017874:Immediate-Early Proteins; D050505:Mutant Proteins; C122111:NXF1 protein, human; D029543:Nucleocytoplasmic Transport Proteins; D016601:RNA-Binding Proteins