# The signaling mechanisms of Arabidopsis CRY2

> **NIH NIH R01** · UNIVERSITY OF CALIFORNIA LOS ANGELES · 2020 · $556,294

## Abstract

Summary
 How cells respond to light and/or timing signal is a fundamental question in biology.
Cryptochromes (CRYs) are evolutionarily conserved blue light receptors or the core circadian clock
components found in all major evolutionary lineages, from bacteria to human. Our long-term goal
is to understand the molecular mechanisms underlying cryptochrome signal transduction and
regulation, using Arabidopsis CRY2 as a model system. Arabidopsis CRY2 is presently the best-
studied plant cryptochrome. My laboratory has discovered most known aspects of the function and
signal transduction mechanisms of CRY2. In the previous funding cycle, we discovered the
photoactivation and regulatory mechanisms of CRY2. We found that photoexcited CRY2
undergoes homodimerization to become active; photoactivated CRY2 is inactivated by the Blue-
light Inhibitors of Cryptochrome (BIC1 and BIC2). Photoactivated CRY2 is also phosphorylated by
four Photoregulatory Protein Kinases (PPK1-4) on at least 24 serine and threonine residues.
Phosphorylated CRY2 is not only fully active but also undergoes ubiquitination and degradation.
However, several important questions of CRY2 signal transduction remain unsolved, including how
CRY2 mediate light regulation of transcriptional and post-transcriptional changes of gene
expression to modulate plant development and how CRY2 itself is regulated by light to modulate
photosensitivity of plants. This renewal application attempt to address those questions based on
results of our recent experiments.

## Key facts

- **NIH application ID:** 10017053
- **Project number:** 5R01GM056265-23
- **Recipient organization:** UNIVERSITY OF CALIFORNIA LOS ANGELES
- **Principal Investigator:** CHENTAO LIN
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2020
- **Award amount:** $556,294
- **Award type:** 5
- **Project period:** 1997-08-01 → 2022-08-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10017053

## Citation

> US National Institutes of Health, RePORTER application 10017053, The signaling mechanisms of Arabidopsis CRY2 (5R01GM056265-23). Retrieved via AI Analytics 2026-05-23 from https://api.ai-analytics.org/grant/nih/10017053. Licensed CC0.

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