Figure 3.

The single C₂H₂ zinc finger in the carboxyl terminus of REST is sufficient to mediate repression of type II sodium channel reporter genes. (A) Schematic representation of the REST expression vector and type II-CAT reporter genes. Relative locations of distinct domains in REST are indicated. (B) Representative autoradiogram (Left) shows TLC fractionation of acetylated forms of chloramphenicol from PC12 cells cotransfected with the different REST constructs shown and the RE1-type II-CAT reporter gene. Other symbols are the same as in Fig. 1. A histogram (Right) shows a compilation of CAT activity from four independent experiments using the REST constructs indicated for the autoradiogram. Standard errors of the mean are shown. (C) Western blot analysis of COS cells transfected with the wild-type (REEX1) and mutated (REEX1M1) cDNAs. Upper arrowhead denotes overexpressed REST protein (200 kDa) and lower arrowhead denotes cross-reacting endogenous protein migrating at 116 kDa (16).