# Genetic and biochemical dissection of anterograde signaling for controlling plastid transcription

> **NIH NIH R01** · UNIVERSITY OF CALIFORNIA RIVERSIDE · 2024 · $319,963

## Abstract

Abstract
The control of organellar gene expression is critical for the cellular programming of all eukaryotic
organisms. While perturbing mitochondrial gene expression leads to human pathologies, including cancer,
altering plastid gene expression can kill plants. However, the cell signaling mechanisms that control
organellar gene expression remain poorly understood. The long-term goal of the PI’s laboratory is to utilize
the light-induced plastid differentiation into photosynthetically active chloroplasts in Arabidopsis as a genetic
model to interrogate cell signaling mechanisms for controlling organellar gene expression. The current data
support the central hypothesis that the red and far-red photoreceptor phytochrome B promotes the
degradation of a small family of phytochrome-interacting basic/helix-loop-helix transcription factors in the
nucleus to generate nucleus-to-plastid (anterograde) signals that trigger the assembly and activation of the
multisubunit, bacterial-type plastid RNA polymerase for transcribing plastid photosynthesis genes. Here the PI
propose to utilize a combination of molecular genetics, biochemistry, and genomics approaches to (1)
determine the mechanism initiating anterograde signaling in the nucleus, (2) determine the mechanism of
the assembly of the multisubunit plastid RNA polymerase complex, and (3) determine the mechanism
activating the plastid RNA polymerase. The proposed research is innovative because it utilizes
photoreceptor signaling and chloroplast biogenesis in Arabidopsis as a genetic model to elucidate a
previously uncharacterized anterograde signaling pathway. The PI has developed new forward genetic
approaches and biochemical assays and identified critical components that define the framework of
anterograde signaling. The proposed research is significant, because it is expected to uncover the light
signaling mechanism for initiating chloroplast biogenesis - a long-standing gap in our knowledge of plant
light signaling and the regulation of photosynthesis. Because the control of transcription in plastids shares
intrinsic similarities with that in mitochondria, what we learn in the plastid model is expected to enhance the
understanding of the general principles of cell signaling mechanisms in controlling organellar gene expression,
including the regulation of mitochondrial gene expression, and therefore, will ultimately contribute to the
understanding of the mechanisms underlying the misregulations of mitochondrial gene expression in human
diseases.

## Key facts

- **NIH application ID:** 10803458
- **Project number:** 2R01GM132765-05
- **Recipient organization:** UNIVERSITY OF CALIFORNIA RIVERSIDE
- **Principal Investigator:** Meng Chen
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2024
- **Award amount:** $319,963
- **Award type:** 2
- **Project period:** 2020-02-07 → 2028-05-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10803458

## Citation

> US National Institutes of Health, RePORTER application 10803458, Genetic and biochemical dissection of anterograde signaling for controlling plastid transcription (2R01GM132765-05). Retrieved via AI Analytics 2026-06-01 from https://api.ai-analytics.org/grant/nih/10803458. Licensed CC0.

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