FIG. 1.

Us9 amino acid sequence and gene constructs. (A) Amino acid sequence of the Us9 open reading frame. The two in-frame methionine residues (#), the potential tyrosine kinase phosphorylation sites (∗), and the potential casein kinase I and II sites (∧) are indicated. The potential N-linked glycosylation (NXS/T) sequence is double underlined. The putative transmembrane domain is underlined, and the surrounding basic residues are indicated (+). (B) Diagrams of all the Us9 constructs used in this study. The two in-frame methionine residues (M), the putative transmembrane domain (TM), and the clusters of basic charges (+) are marked. The Us9 protein fusions with GST, the influenza A virus HA epitope, and EGFP are indicated. All constructs depicted are under the transcriptional control of the CMV immediate-early promoter.