Powerful microscope captures motor proteins in unprecedented detail

Amazing stuff! There were lately several reports of other, significant advances in microscopy mentioned here on my blog!

"Almost as soon as there were super-resolution microscopes, scientists pointed them towards molecular motors called kinesins. These proteins, powered by the molecular fuel ATP, drive crucial processes including cell division, cell signalling and intracellular transport by shuttling cargo along protein highways called microtubules. Researchers have long wanted to understand how these motors work, but to visualize them, scientists have had to slow them down or isolate them in simplified, in vitro systems.

Now, in papers published concurrently in Science, two teams working independently have used a super-resolution tool called MINFLUX to study the motor in near-real time at physiologically relevant concentrations of ATP. ...
In the new study, published in March, Hell’s group tested a version of MINFLUX that pulses linear lasers in two directions in the focal plane in quick succession, localizing the protein by finding where the overlapping fluorescence intensities are lowest. By combining multiple measurements, the researchers were able to produce tracks that show where the molecule is moving along the microtubule, like an app that maps out a runner’s path. ...
Ries and his team approached kinesin motion from a different perspective. They used a commercial MINFLUX instrument developed by Abberior, a Göttingen-based company co-founded by Hell, to track the protein in living cells. The crowded and ever-changing cellular environment meant that the group ended up with fewer tracks, but they were able to capture side-stepping, stalling and hops from one microtubule to another — all efforts by the protein to circumvent roadblocks that aren’t typically seen in purified samples. ...

Such advances could open multiple research avenues, especially if they allow researchers to track several proteins, or several sites in proteins, at once. This year, researchers introduced a tool called RESI (resolution enhancement by sequential imaging), which aims to do just that. RESI can label adjacent copies of the same target molecule with different tags, allowing scientists to distinguish between molecules that are less than one nanometre apart. Although RESI currently works only on fixed or stationary molecules, combining its findings with MINFLUX tracking data on non-fixed copies could yield complementary findings about a protein’s arrangement and motion.

Ries is interested in studying other motor proteins, and in a supplementary experiment shared in his paper, applied MINFLUX to the muscle-contracting protein, myosin. ..."

Powerful microscope captures motor proteins in unprecedented detail Called MINFLUX, the super-resolution method allows researchers to track molecules under cellular conditions.

MINFLUX dissects the unimpeded walking of kinesin-1 (no public access)

Direct observation of motor protein stepping in living cells using MINFLUX (no public access)