# Functional nanoscopy of membrane deformations and fission by dynamin superfamily members

> **NIH NIH R01** · UNIVERSITY OF CALIF-LAWRNC LVRMR NAT LAB · 2021 · $429,436

## Abstract

PROJECT SUMMARY
Membrane fission is associated with the breakage of a tiny nanometer-scale membrane neck connecting two
separating/dividing membrane compartments at the late stages of division. Severing this neck in a timely
and leakage-free manner is critical for normal functioning of endomembrane systems, hence membrane
fission is performed by specialized and tightly-regulated protein machinery assembling on the neck. While
our current mechanistic understanding of fission, in life and disease, is heavily based upon in vitro
reconstitution approaches, such approaches rarely (if at all) reproduce confined and crowded environment
of the neck. Instead, in vitro reconstitution has been mostly performed using large (sub-micron to micron
scale) membrane templates of various physico-chemical properties, resulting in controversial outcomes and
precluding rigorous mechanistic analysis of fission. This project is focused on creation of the next-
generation in vitro approaches that reconstruct and quantify membrane fission at physiological length/time
scales. We will combine nanotechnology with modern biophysical approaches and protein engineering to
solve the long-standing puzzle of membrane fission mediated by the proteins of dynamin superfamily, which
are intimately involved in intracellular fusion/fission and directly linked to various human pathologies. We
will approach this problem from several different angles:
 - We will perform single-molecule analysis of dynamin oligomerization on membrane surfaces with
 precisely (2 nm) calibrated curvature (10-1 to 10-2 nm range) to identify and characterize
 elementary mechano-chemical units assembled by dynamin. We will determine (i) the
 pathways of dynamin oligomerization/self-assembly on a curved membrane surface, (ii) the
 size/geometrical arrangement of minimal oligomers capable of cooperative GTP hydrolysis and (iii)
 the effects of membrane curvature on self-assembly and GTPase activity of small dynamin oligomers.
 - We will assess membrane activity of individual dynamin oligomers (dimers and higher order
 multimers) at nano-confined membrane templates to determine how the force fields
 produced by dynamin are coupled to lipid rearrangements throughout fission. We will
 (i) measure the local forces produced by different dynamin oligomers and quantify associated
 membrane deformations and instabilities, and (ii) determine pathway(s) of lipid rearrangements and
 their dependence on the size/geometry of dynamin complexes and geometrical/mechanical
 parameters of membrane templates.
 - We will analyze effects of auxiliary proteins and critical mutations of dynamins, compare the self-
 assembly and fission pathways for different members of dynamin superfamily to distinguish
 general and protein-specific parameters (perhaps, even specific pathways) of
 membrane fission and unravel molecular mechanisms behind functional evolution
 and regulation of dynamin fission machinery.

## Key facts

- **NIH application ID:** 10246322
- **Project number:** 5R01GM121725-05
- **Recipient organization:** UNIVERSITY OF CALIF-LAWRNC LVRMR NAT LAB
- **Principal Investigator:** Vadim A Frolov
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2021
- **Award amount:** $429,436
- **Award type:** 5
- **Project period:** 2017-09-26 → 2023-07-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10246322

## Citation

> US National Institutes of Health, RePORTER application 10246322, Functional nanoscopy of membrane deformations and fission by dynamin superfamily members (5R01GM121725-05). Retrieved via AI Analytics 2026-05-21 from https://api.ai-analytics.org/grant/nih/10246322. Licensed CC0.

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