Fig 2.

Interaction of USP22 with SIRT1 is highly specific and requires the ZnF-UBP domain. (A) C-terminally FLAG-tagged SIRT1 to SIRT7 were overexpressed in HEK 293T cells, immunoprecipitated with FLAG resin, and immunoblotted for endogenous USP22. (B) Various N-terminal FLAG-tagged deubiquitinating enzymes and acetyltransferases were overexpressed, purified as described for panel A, and immunoblotted for endogenous SIRT1. (C and D) Truncations of FLAG-HA-USP22 (C) and FLAG-HA-SIRT1 (D) were generated and tested for their ability to interact with endogenous SIRT1 or USP22, respectively. Domain maps of USP22 (C) and SIRT1 (D) indicate truncations used in interaction studies.