1. Physics of Living Systems
  2. Neuroscience

Physical limits to magnetogenetics

  1. Markus Meister  Is a corresponding author
  1. California Institute of Technology, United States
https://doi.org/10.7554/eLife.17210
Share this article
Cite this article
  1. Markus Meister
(2016)
Physical limits to magnetogenetics
eLife 5:e17210.
https://doi.org/10.7554/eLife.17210
  2. Download BibTeX
  3. Download .RIS

Abstract

This is an analysis of how magnetic fields affect biological molecules and cells. It was prompted by a series of prominent reports regarding magnetism in biological systems. The first claims to have identified a protein complex that acts like a compass needle to guide magnetic orientation in animals (Qin et al., 2016). Two other articles report magnetic control of membrane conductance by attaching ferritin to an ion channel protein and then tugging the ferritin or heating it with a magnetic field (Stanley et al., 2015; Wheeler et al., 2016). Here I argue that these claims conflict with basic laws of physics. The discrepancies are large: from 5 to 10 log units. If the reported phenomena do in fact occur, they must have causes entirely different from the ones proposed by the authors. The paramagnetic nature of protein complexes is found to seriously limit their utility for engineering magnetically sensitive cells.

Article and author information

Author details

  1. Markus Meister

    Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, United States
    For correspondence
    meister@caltech.edu
    Competing interests
    The authors declare that no competing interests exist.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0003-2136-6506

Funding

No external funding was received for this work.

Reviewing Editor

  1. David E Clapham, Howard Hughes Medical Institute, Boston Children's Hospital, United States

Version history

  1. Received: April 25, 2016
  2. Accepted: August 15, 2016
  3. Accepted Manuscript published: August 16, 2016 (version 1)
  4. Accepted Manuscript updated: August 23, 2016 (version 2)
  5. Version of Record published: September 8, 2016 (version 3)

Copyright

© 2016, Meister

This article is distributed under the terms of the Creative Commons Attribution License permitting unrestricted use and redistribution provided that the original author and source are credited.

Metrics

  • 21,590
    Page views
  • 3,553
    Downloads
  • 125
    Citations

Article citation count generated by polling the highest count across the following sources: Crossref, Scopus, PubMed Central.

Download links

A two-part list of links to download the article, or parts of the article, in various formats.

Downloads (link to download the article as PDF)

Open citations (links to open the citations from this article in various online reference manager services)

Cite this article (links to download the citations from this article in formats compatible with various reference manager tools)

  1. Markus Meister
(2016)
Physical limits to magnetogenetics
eLife 5:e17210.
https://doi.org/10.7554/eLife.17210

Categories and tags

Further reading

    1. Neuroscience

    Possible magneto-mechanical and magneto-thermal mechanisms of ion channel activation in magnetogenetics

    Mladen Barbic
    Research Article Updated

    The palette of tools for perturbation of neural activity is continually expanding. On the forefront of this expansion is magnetogenetics, where ion channels are genetically engineered to be closely coupled to the iron-storage protein ferritin. Initial reports on magnetogenetics have sparked a vigorous debate on the plausibility of physical mechanisms of ion channel activation by means of external magnetic fields. The criticism leveled against magnetogenetics as being physically implausible is based on the specific assumptions about the magnetic spin configurations of iron in ferritin. I consider here a wider range of possible spin configurations of iron in ferritin and the consequences these might have in magnetogenetics. I propose several new magneto-mechanical and magneto-thermal mechanisms of ion channel activation that may clarify some of the mysteries that presently challenge our understanding of the reported biological experiments. Finally, I present some additional puzzles that will require further theoretical and experimental investigation.

    1. Physics of Living Systems
    2. Neuroscience

    Magnetogenetics: Problems on the back of an envelope

    Polina Anikeeva, Alan Jasanoff
    Insight

    Claims that magnetic fields can be used to manipulate biological systems contradict some basic laws of physics.

    1. Cell Biology
    2. Physics of Living Systems

    A mechanosensing mechanism controls plasma membrane shape homeostasis at the nanoscale

    Xarxa Quiroga, Nikhil Walani ... Pere Roca-Cusachs
    Research Article

    As cells migrate and experience forces from their surroundings, they constantly undergo mechanical deformations which reshape their plasma membrane (PM). To maintain homeostasis, cells need to detect and restore such changes, not only in terms of overall PM area and tension as previously described, but also in terms of local, nano-scale topography. Here we describe a novel phenomenon, by which cells sense and restore mechanically induced PM nano-scale deformations. We show that cell stretch and subsequent compression reshape the PM in a way that generates local membrane evaginations in the 100 nm scale. These evaginations are recognized by I-BAR proteins, which triggers a burst of actin polymerization mediated by Rac1 and Arp2/3. The actin polymerization burst subsequently re-flattens the evagination, completing the mechanochemical feedback loop. Our results demonstrate a new mechanosensing mechanism for PM shape homeostasis, with potential applicability in different physiological scenarios.