Trafficking of ODV-E66 is mediated via a sorting motif and other viral proteins: facilitated trafficking to the inner nuclear membrane.
The N-terminal 33 aa of the envelope protein ODV-E66 are sufficient to traffic fusion proteins to intranuclear membranes and the ODV envelope during infection with Autographa californica nucleopolyhedrovirus. This sequence has two distinct features: (i) an extremely hydrophobic sequence of 18 aa and (ii) positively charged amino acids close to the C-terminal end of the hydrophobic sequence. In the absence of infection, this sequence is sufficient to promote protein accumulation at the inner nuclear membrane. Covalent cross-linking results show that the lysines of the motif are proximal to FP25K and/or BV/ODV-E26 during transit from the endoplasmic reticulum to the nuclear envelope. We propose that the 33 aa comprise a signature for sorting proteins to the inner nuclear membrane (sorting motif) and that, unlike other resident proteins of the inner nuclear membrane, ODV-E66 and sortingmotif fusions do not randomly diffuse from their site of insertion at the endoplasmic reticulum to the nuclear envelope and viral-induced intranuclear membranes. Rather, during infection, trafficking is mediated by protein-protein interactions.
Braunagel
Sharon C
SC
Department of Biology,Texas Agricultural Experiment Station, Texas A and M University, College Station, TX 77843-2475, USA.
Williamson
Shawn T
ST
Saksena
Suraj
S
Zhong
Zhenping
Z
Russell
William K
WK
Russell
David H
DH
Summers
Max D
MD
D000595:Amino Acid Sequence; D000818:Animals; D037281:Calnexin / Q000378:metabolism; D037282:Calreticulin / Q000378:metabolism; D002460:Cell Line; D004285:Dogs; D004721:Endoplasmic Reticulum / Q000737:chemistry / Q000378:metabolism; D017261:Glycosylphosphatidylinositols; D007313:Insecta; D034882:Lamins / Q000378:metabolism; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism*; D008969:Molecular Sequence Data; D009685:Nuclear Envelope / Q000737:chemistry / Q000378:metabolism* / Q000648:ultrastructure; D021382:Protein Sorting Signals; D021381:Protein Transport / Q000502:physiology*; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D016415:Sequence Alignment; D014759:Viral Envelope Proteins / Q000235:genetics / Q000378:metabolism*
D037282:Calreticulin; D017261:Glycosylphosphatidylinositols; D034882:Lamins; D008565:Membrane Proteins; D021382:Protein Sorting Signals; D011993:Recombinant Fusion Proteins; D014759:Viral Envelope Proteins; D037281:Calnexin