FIG. 6.

N-terminal degron in GADD34. (A) Schematic represents all GADD34 proteins analyzed in turnover studies. The positions of a putative ER membrane-association domain (MEMB), PEST, and PP1-binding domains are shown in boxes. (B) C-terminally GFP-tagged GADD34 proteins were expressed in HEK293T cells and subjected to turnover studies. (C) GADD34 proteins fused at the N terminus (GFP-GADD34) or the C terminus (GADD34-GFP) with GFP were expressed in HEK293T cells, and their rate of degradation analyzed as described in Materials and Methods. Similarly, turnover of an N-terminally tagged FLAG-GADD34 was compared to that of the internally tagged FLAG(109)GADD34. (D) Quantification of degradation of all GFP-fusion proteins analyzed in the present study is shown and represents the summary of three independent experiments. All data are shown with standard errors. In panels B and C, tubulin immunoblots served as loading controls.