Stefanie King

Program: Plant and Microbial Biosciences

Current advisor: Dmitri A. Nusinow, PhD

Undergraduate university: Rice University, 2021

Enrollment year: 2021

Research summary
I aim to identify the protein regions critical for complex formation and transcription regulation enacted by a light- and temperature-responsive protein complex in the Arabidopsis thaliana circadian clock.

The plant circadian clock is an internal 24-hour oscillator synchronizing with environmental cycles to produce biological rhythms. Environmental signals are sensed and transduced into cycling gene expression by light- and temperature-responsive transcription factors (TFs). These proteins tightly regulate time-of-day-specific transcription activation and repression of their targets. The intrinsically disordered regions (IDRs) often found in these TFs allow for forming large protein complexes that fine-tune the regulation they enact.
REVEILLE 8 (RVE8), NIGHT LIGHT-INDUCIBLE AND CLOCK REGULATED 1 (LNK1), and COLD REGULATED GENE 27 (COR27) are among these important TFs. The RVE8-LNK1 (R-L) complex serves as a key transcriptional on-switch in the circadian clock, and COR27 binding turns the complex into an off-switch. The RVE8-LNK1-COR27 (R-L-C) complex is responsive to changes in the environment given LNK1 and COR27’s induction in response to light and cold, respectively. COR27 protein is also stabilized by blue light. While the individual components of this complex have been well studied, the structure and transcriptional regulation mechanism of the newly discovered R-L-C complex remain unknown. Given its role as a key environmentally responsive transcription regulator in the clock, I seek to identify the protein regions critical for R-L-C complex formation and transcription regulation, and to determine the mechanism of COR27-mediated antagonization of R-L to repress transcription of its targets.

Graduate publications
Sorkin ML, Tzeng SC, King S, Romanowski A, Kahle N, Bindbeutel R, Hiltbrunner A, Yanovsky MJ, Evans BS, Nusinow DA. 2023 COLD REGULATED GENE 27 and 28 Antagonize the Transcriptional Activity of the RVE8/LNK1/LNK2 Circadian Complex. Plant Physiol, 192(3):2436-56. PMCID: PMC10315267