# Understanding and leveraging molecular diversity within the phytochrome superfamily

> **NIH NIH R35** · UNIVERSITY OF CALIFORNIA AT DAVIS · 2024 · $7,016

## Abstract

Project Summary: Supplement for $7,016 for purchase of a spectroradiometer
 Understanding and leveraging molecular diversity within the phytochrome superfamily
 R35 GM139598; Principal Investigator: J. Clark Lagarias
Our proposal focuses on the phytochrome superfamily of photoreceptors. We have a longstanding
interest in these proteins and in the linear tetrapyrrole (bilin) chromophores they use to detect light.
Members of this superfamily control growth and development of plants (seed germination,
photomorphogenesis, shade avoidance, and flowering, among other processes), making
phytochromes important research targets for enhancing agricultural efficiency to meet the demand
for food in the face of increasing human population. Other members of this family allow bacteria
to move, form biofilms, or adjust their metabolism in response to the light environment.
Phytochromes and cyanobacteriochromes (CBCRs), the two families of proteins in the
phytochrome superfamily, are able to detect every color of light between the near-ultraviolet and
the near-infrared, including red and far-red wavelengths that are optimal for imaging in
mammalian tissue. Thus, basic research to understand phytochrome diversity, the mechanisms
underlying its function in plants, algae, and bacteria, and development of new imaging tools well
fits the mission of NIGMS.
Research in the Lagarias lab leverages the natural diversity that has arisen in this superfamily
during evolution. We seek to understand the mechanisms that allow these proteins to sense
different colors of light, to either exhibit bright fluorescence or switch between photostates, to
integrate signals such as temperature or pH with light, and to report this information to the cell. In
the course of this research, we have also developed useful reagents including fluorescent
phytochromes, constitutively active plant phytochromes, and phytochrome-null plants. In the next
five years, we envision making further progress in understanding detection of far-red and near-
infrared light by these proteins. We expect to learn how to “re-tune” the color-sensing mechanisms
of a range of phytochromes and CBCRs, an insight which be applied to existing reagents and
systems to allow new imaging applications, multiplexing of synthetic biology systems to respond
to different colors, or tissue-specific applications in which specific targets are activated with light
rather than with gene promoters. These goals fit well with our overall goals of understanding of
the photochemical, biophysical, and biological processes of this family and potentially yield
advances in biomedical imaging and synthetic biology via development of a knowledge base,
improving fundamental methods with new reagents, and leveraging new technologies.

## Key facts

- **NIH application ID:** 11099518
- **Project number:** 3R35GM139598-04S1
- **Recipient organization:** UNIVERSITY OF CALIFORNIA AT DAVIS
- **Principal Investigator:** JOHN CLARK LAGARIAS
- **Activity code:** R35 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2024
- **Award amount:** $7,016
- **Award type:** 3
- **Project period:** 2021-01-01 → 2025-11-30

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/11099518

## Citation

> US National Institutes of Health, RePORTER application 11099518, Understanding and leveraging molecular diversity within the phytochrome superfamily (3R35GM139598-04S1). Retrieved via AI Analytics 2026-05-24 from https://api.ai-analytics.org/grant/nih/11099518. Licensed CC0.

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