# Molecular and cellular biology of the phage nucleus and spindle

> **NIH NIH R01** · UNIVERSITY OF CALIFORNIA, SAN DIEGO · 2024 · $250,000

## Abstract

Project Summary
The ability to establish and maintain subcellular organization is a fundamental design principle of biological
systems. We recently discovered that many jumbo phage establish surprisingly complex subcellular organization
involving a nucleus-like structure or “phage nucleus” that compartmentalizes phage replication within the host
cytoplasm. The phage nucleus carries out many functions previously only attributed to the eukaryotic nucleus
including segregation of key processes (DNA replication and repair, mRNA synthesis, protein synthesis and
metabolism) and selective protein import and mRNA export. However, the phage nucleus is structurally dissimilar
to the eukaryotic nucleus, being mainly composed of a single layer of a phage-encoded protein and lacking
evident openings for exchange with the cytoplasm instead of a double-layer lipid membrane containing prominent
pore complexes. We have identified the key protein that makes up the phage nucleus shell; however, the
components required to assemble a fully functional phage nucleus and their roles in this multipurpose structure
remain unknown. Here we aim to identify and characterize additional proteins that are required to construct a
fully functional phage nucleus to gain greater insight into the biology of these understudied viruses and the
underlying principles of subcellular compartmentalization previously observed almost exclusively in eukaryotes.
We will use an integrative approach that combines genetics, cell biology, biochemistry and in situ and in vitro
structural biology approaches to study the jumbo phage in Pseudomonas and E. coli. Together, the knowledge
gained from this project will provide insight into fundamental principles underlying subcellular organization.

## Key facts

- **NIH application ID:** 11118112
- **Project number:** 3R01GM129245-07S1
- **Recipient organization:** UNIVERSITY OF CALIFORNIA, SAN DIEGO
- **Principal Investigator:** JOSEPH A POGLIANO
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2024
- **Award amount:** $250,000
- **Award type:** 3
- **Project period:** 2018-09-06 → 2026-07-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/11118112

## Citation

> US National Institutes of Health, RePORTER application 11118112, Molecular and cellular biology of the phage nucleus and spindle (3R01GM129245-07S1). Retrieved via AI Analytics 2026-05-23 from https://api.ai-analytics.org/grant/nih/11118112. Licensed CC0.

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