FIG. 6.

Identification of mPER2 sequences necessary for phosphorylation-dependent degradation. (A) Two specific internal deletions in mPER2 block the calyculin A-induced degradation. The indicated internal deletions were engineered in the mPER2(450-763) background and transiently expressed in HEK293 cells. Cells were treated with vehicle (−) or calyculin A (+; 80 nM) for 60 min, and the amount of mPER2 was assessed as in Fig. 1A, with anti-Myc antibodies. (B) Summary of the constructs used and the results obtained in panel A. wt, wild type; Cal. A, calyculin A.