# Structure and Function of the Nuclear Pore Complex by Cryogenic-EM

> **NIH GM R35** · BOSTON UNIVERSITY MEDICAL CAMPUS · 2026 · $408,750

## Abstract

Structure and Function of the Nuclear Pore Complex by Cryogenic-EM
Abstract
The nucleus is compartmentalized by double membranes of the Nuclear Envelope (NE) and
macromolecules must cross this barrier during cell growth and differentiation. The Nuclear Pore Complex
(NPC) forms a conduit for the bidirectional transport of proteins and RNA-protein complexes between the
cytoplasm and nuclear interior. Regulated access to this gateway is used to control gene expression.
Together, four co-axial rings form a cylindrical scaffold comprised of Nucleoporins (Nups). This scaffold
anchors Nups with flexible FG-repeats (FXFG/GLFG) that project into the central channel to form a barrier
in the constricted ground state, while FG-repeats in the dilated NPC provide binding sites for the transport
of karyopherin/importin cargo complexes. A deeper understanding of this mechano-sensitive translocation
channel requires a detailed knowledge of the core scaffold and the enigmatic central transporter.
 In a series of recent papers, we determined Nup domain models for isolated and in situ yeast NPCs
with cryogenic electron tomography in their ground state and dilated conformations, respectively. We
extended this work with cryogenic-EM and single particle methods to study the isolated NPC and provide a
composite, multiscale structure of the 8-fold symmetric core scaffold. To date, we have analyzed NPCs
from growing cells engaged in transport, whose plug-like feature in the central channel is comprised of
cylindrically-arrayed FG repeats and cargo complexes. However, the dynamic core scaffold contracts to a
ground state configuration during solubilization of the NE and purification, due to the loss of lateral
membrane tension. To extend our previous studies, a one-step NPC purification has been refined to
minimize aggregation and stabilize membrane protein anchors. We will use stationary cells to provide a
more uniform NPC population for structure determination that will focus on the core sc

## Key facts

- **NIH application ID:** 11324518
- **Project number:** 5R35GM156236-02
- **Recipient organization:** BOSTON UNIVERSITY MEDICAL CAMPUS
- **Principal Investigator:** CHRISTOPHER W AKEY
- **Activity code:** R35 (R01, R21, SBIR, etc.)
- **Funding institute:** GM
- **Fiscal year:** 2026
- **Award amount:** $408,750
- **Award type:** 5
- **Project period:** 2025-05-01T00:00:00 → 2030-03-31T00:00:00

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/11324518

## Citation

> US National Institutes of Health, RePORTER application 11324518, Structure and Function of the Nuclear Pore Complex by Cryogenic-EM (5R35GM156236-02). Retrieved via AI Analytics 2026-07-08 from https://api.ai-analytics.org/grant/nih/11324518. Licensed CC0.

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