# Writers and Erasers of Ubiquitin Moieties in Control of Cell-to-Cell Transport in Plants

> **NIH NIH R35** · STATE UNIVERSITY NEW YORK STONY BROOK · 2022 · $398,750

## Abstract

PROJECT SUMMARY
 Perhaps one of the most intriguing, yet least studied, aspects of macromolecular
transport is traffic through intercellular connections. These connections are termed tunneling
nanotubes in mammals and plasmodesmata (Pd) in plants. Whereas both mammalian and plant
viruses utilize cell-to-cell transport pathways, the first such capability was identified for
movement proteins (MPs) of plant viruses, the transport of which via Pd represents a
conceptual paradigm for intercellular traffic of macromolecules. Whereas the main research
effort in the field, including our lab, has been focused on the mechanism of MP cell-to-cell
movement, the important question of how the movement mechanism is controlled remained
largely unaddressed. The proposed research program aims to begin filing this gap in our
knowledge. Research in my laboratory focuses on three diverse aspects of plant biology and
plant-pathogen interactions: (i) cell-to-cell transport of the movement protein (MP) of the model
plant virus TMV; (ii) bacterium-to-plant cell transport of proteins and nucleic acids during genetic
transformation by Agrobacterium; and (iii) epigenetic regulation of gene expression, including
the pathogen response genes, by histone modifications. Recently, all three projects converged
on the regulatory roles of ubiquitin writers (E3 ligases) and erasers (deubiquitinases) in the plant
life cycle in general, and in the MP cell-to-cell transport in particular. Specifically, our findings
suggest that ubiquitin writers and erasers dynamically control two major aspects of the MP cell-
to-cell transport process: cargo stability/availability and assembly/disassembly of the Pd
transport machinery. The proposed program leverages the wealth of molecular tools and
experimental approaches that we have developed along the years to study cell-to-cell transport
of plant viruses and roles of protein ubiquitylation/deubiquitylation in plant-pathogen interactions
to address a new (and, so far, completely unresearched) level of regulation of intercellular
transport through Pd by reversible action of ubiquitin writers and erasers of the plant cell. We
believe that this goal is innovative and likely to be transformative also for studies of transport of
other proteins, viral and plant, through Pd.

## Key facts

- **NIH application ID:** 10328387
- **Project number:** 1R35GM144059-01
- **Recipient organization:** STATE UNIVERSITY NEW YORK STONY BROOK
- **Principal Investigator:** VITALY H CITOVSKY
- **Activity code:** R35 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2022
- **Award amount:** $398,750
- **Award type:** 1
- **Project period:** 2022-03-16 → 2027-01-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10328387

## Citation

> US National Institutes of Health, RePORTER application 10328387, Writers and Erasers of Ubiquitin Moieties in Control of Cell-to-Cell Transport in Plants (1R35GM144059-01). Retrieved via AI Analytics 2026-05-24 from https://api.ai-analytics.org/grant/nih/10328387. Licensed CC0.

---

*[NIH grants dataset](/datasets/nih-grants) · CC0 1.0*