Checkpoints and "Molecular Sieve" Let Protein Molecules Go the Right Way

In order to improve the efficiency of information processing, our nerve cells feel the information, the command information is separated. This requires the protein molecules that "run errands" for information to find their correct parts. In the past, it was generally believed that it was because the protein molecules related to signal processing were "smart" and would automatically find the "direction". However, Shanghai scientists recently discovered that our neuron cells have set up a clever "checkpoint"-molecular sieve. This flexible net can identify the "identity" of the molecule, so that the protein molecules can go the right way, enter the opposite door, and do the right thing. Today's "Cell" magazine published this breakthrough discovery made by researchers Pu Muming and Duan Shumin from the Institute of Neuroscience, Shanghai Academy of Health Sciences, Chinese Academy of Sciences, and their student Song Yanhong.

Neurons in the brain can be divided into two parts: the dendrites and axons. The enlarged cysts and the dendrites are mainly responsible for sensing the information from the outside world. And long axons, like highways, are responsible for quickly transmitting information to other relevant nerve cells.

The molecular sieve is placed at the junction of the somatic dendrites and axons. The method of verifying "identity" at this checkpoint is very special. It does not directly check the "identity card" of the protein, but waits for the protein to pass through. Don't underestimate this net. If you don't have a certain "horsepower", you don't want to pass-"Small-displacement cars are prohibited from being elevated". As a result, protein "information couriers" have to find the "taxi" in nerve cells-motor molecules. However, in the world of neurons, motor molecules are identified as "customers". Only specific proteins can catch motor molecules with strong enough horsepower, smoothly open the mesh, cross the molecular sieve, and drive on the axon "highway". In this way, a variety of different proteins set foot on their own should go the road.

Song Yuanhong, the main author of the paper and a doctoral student, told reporters that the research results removed the "smart" halo of motor proteins. The discovery of molecular sieves confirmed that motor molecules cannot recognize the difference between axon protein molecules and somatic dendrite protein molecules. When proteins carry specific motor molecules to and from axons and somatic dendrites, molecular sieves play the final recognition role.