what is the “magneto” protein, & why are references to a 2016 paper suddenly in my feed?

A few days back an article in The Guardian popped up in my newsfeed. It was quite old – published in 2016 – but it looked interesting, so I read it & also tracked down the original paper.

The article & research paper describe work done to develop and test a potential tool for unpicking and understanding the neural mechanisms that underpin complex animal behaviour. In 2016 there were 2 existing tools for “remotely controlling” groups of related neurons (nerve cells): one – optogenetics – uses pulsed laser light, and the other – chemogenetics – uses GE proteins targeted to particular cells and turned on by specialised drugs. Optogenetics works on a millisecond time scale, but is invasive as optical fibres have to be surgically inserted into an animal’s brain. Chemogenetics is slower (in the order of seconds) but does act more widely in the brain.

The technique trialled in the 2016 paper extended earlier work looking at genetically-engineering proteins to make them sensitive to electromagnetic radiation. It used a protein named TRPV4, which is a transport protein embedded in the cell membrane. When exposed to changes in temperature and pressure, a pore in the middle of the protein opens, which allows electrical current to move across the membrane. The researchers reasoned that if they could make a version of TRPV4 that responded to a transient electromagnetic field, and could engineer neurons to express the protein (by transfecting them with the modified DNA sequence), they’d have a tool for examining the impact of turning those neurons on & off. (For the mice used in one part of the research, the study was no less invasive than the optogenetics technique, as it required injections deep into the animals’ brains.)

To this end, they developed what they described as a “magnetically sensitive actuator, ‘Magneto'”, made up of the TRPV4 molecule fused to the iron-storage protein ferritin. which happens to be paramagnetic. “When the fused GE protein was expressed – in both human kidney cells in cell culture (aka in vitro) and neurons in the brains of zebrafish and mice – the researchers were able to induce electric currents across the cell membrane in vitro and changes in behaviour in vivo when cells and animals were exposed to an electromagnetic field. For the in vivo work on live animals, the DNA sequence for the ‘Magneto’ protein was ferried into cells using a viral vector.

It’s worth emphasising that the modified protein wasn’t produced throughout the body as it the DNA sequence also included regulatory sections that allowed it to be expressed only in some types of neurons. For the mice, this involved “a deep brain structure containing dopamine-producing neurons that are involved in reward and motivation” – the injected mice preferred to stay within an EM field as this triggered dopamine release.

An interesting test of concept – but…

The number of animals used in the various experiments was very small: 5 fish, 5, 9, and 12 mice (as far as I can tell from the paper). More significantly, other researchers tried the same technique without success – see here, here, and here, with the first group saying that their findings raised “serious doubt about the previous claim that Magneto can readily be used as a magnetic actuator.”

So why has the Guardian article turned up in my feed lately? Probably because it’s been weaponised by some of those opposed to covid-19 vaccinations. Supposedly, when someone’s been received the vaccine, magnets stick to the vaccination site, and – supposedly – this is because the vaccine also contains the “Magneto protein”. However, none of the vaccines contain any magnetic metals (two – AstraZeneca & Sputnik V – contain tiny amounts of magnesium ions). Even if they did, the total volume – 0.3mL – of a dose is so small that even if all it contained was the paramagnetic protein ferritin, there’d be no effect. I mean, if there was, you’d surely expect fridge magnets to stick to people All.The.Time. given the amount of ferritin circulating in your bloodstream. And of course, the vaccine ingredient list is publicly available and the contents relatively easy to check.

In other words, the claim suffers from a lack of any prior plausibility. And it’s ridiculously easy to fake the appearance of a magnet sticking to your skin. Vaseline on the back of the disc works quite well…