Table 1. Posttranslational Regulation of Arabidopsis Clock Proteins.
| Core Clock Component | Epigenetic Regulators | Phosphorylation | Ubiquitination Degradation | Protein–Protein Interaction |
|---|---|---|---|---|
| CCA1 | SDG2/ATXR3, JMJ30/JMJD5, TPL-HDA6 | CK2 | CK2, CCA1, LHY, DET1, FHY3 | |
| LHY | SDG2/ATXR3, JMJ30/JMJD5, TPL-HDA6 | CK2 | SINAT5 | CK2, CCA1, LHY, DET1 |
| TOC1 | CCA1, LCL5, SDG2/ATXR3 | Unknown | ZTL, FKF1, LKP2 | PRR3, PRR5, CHE, ZTL, FKF1, LKP2 |
| PRR3 | Unknown | TOC1 | ||
| PRR5 | Unknown | ZTL, FKF1, LKP2 | TOC1, ZTL, FKF1, LKP2, TPL | |
| PRR7 | SDG2/ATXR3 | TPL | ||
| PRR9 | SDG2/ATXR3 | TPL | ||
| GI | COP1 | ELF3, COP1, HSP90, ZTL, FKF1, LKP2 | ||
| CHE | TOC1 | |||
| ELF3 | ELF4, LUX, COP1, GI | |||
| ELF4 | ELF3, LUX | |||
| LUX | SDG2/ATXR3 | ELF3, ELF4 |
The molecular components responsible for the different posttranslational regulatory mechanisms at the core of the clock are listed. In some instances, the specific molecular components responsible for the modification remain to be discovered (unknown).