ORCID

http://orcid.org/0000-0002-3897-2636

Date of Award

Winter 12-15-2022

Author's School

Graduate School of Arts and Sciences

Author's Department

Biology & Biomedical Sciences (Plant & Microbial Biosciences)

Degree Name

Doctor of Philosophy (PhD)

Degree Type

Dissertation

Abstract

The plant circadian clock is an endogenous timekeeping mechanism that uses daylength and temperature cycles to synchronize internal physiology with the external environment. Much of our understanding of the clock in the model plant Arabidopsis thaliana comes from genetic approaches. In this thesis, I use affinity purification coupled with mass spectrometry (APMS) to identify protein-protein interactions for core clock components on a proteomic scale. I developed and optimized a protocol to perform APMS on a core set of circadian clock proteins: CIRCADIAN CLOCK ASSOCIATED 1 (CCA1), LATE ELONGATED HYPOCOTYL (LHY), PSEUDORESPONSE REGULATOR 5 (PRR5), PRR7, PRR9, TIMING OF CAB 1 (TOC1)/PRR1, FIONA 1 (FIO1), JUMONJI DOMAIN CONTAINING 5 (JMJD5), NIGHT LIGHT-INDUCIBLE AND CLOCK-REGULATED 1 (LNK1), LNK2, and REVEILLE 8 (RVE8). The combined dataset of proteins coprecipitated with these clock factors represents a circadian clock “interactome” that is publicly available for future studies. I chose to follow up on an interaction between RVE8/LNK1/LNK2 and two proteins previously unrelated to these clock components, COLD-REGULATED PROTEIN 27 (COR27) and COR28. I found that these proteins form a complex in the early evening that serves to regulate RVE8 protein stability and to block the transcriptional activity of RVE8-LNK1/2. Together, this work demonstrates the power of proteomics to make new discoveries in the plant circadian clock and I hope that my datasets will be a useful tool for future studies.

Language

English (en)

Chair and Committee

Dmitri A Nusinow

Committee Members

Elizabeth Haswell

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