Fig 2.

Pin1 interacts with EBV DNA polymerase BALF5. (A) GST-Pin1 binds to BALF5. Proteins from B95-8 cells, induced with TPA, A23187, and sodium butyrate for 24 h, were harvested and lysed in GST lysis buffer. GST pulldown assays were carried out using GST, GST-Pin1, or GST-Pin1 W34A. Pin1 W34A cannot bind with target proteins because of the mutation in its WW domain. (B) Phosphorylation-dependent association of Pin1. A GST pulldown assay was carried out as described for panel A except that the B95-8 cell lysate was incubated with lambda protein phosphatase (PP) (New England BioLabs) for 30 min at 30°C as indicated on the figure. (C) Immunoprecipitation assays confirmed the interaction. Cell proteins from lytic B95-8 lysate were subjected to immunoprecipitation using anti-BALF5 antibodies or normal IgG. The precipitates were then immunoblotted using anti-BALF5 or -Pin1 antibodies. α, anti. Arrowhead indicates size of Pin1. (D) Exogenously overexpressed BALF5 can bind to Pin1. Cell proteins from HEK293T cells transfected with BALF5 expression vector were subjected to GST pulldown assay. IB, immunoblotting; CBB, Coomassie brilliant blue. k, kilodaltons.