Scientists unveil the mechanism of maintaining the polarity of nerve cells

Electricity has positive and negative poles, magnetism has north and south poles, and cells also have polarity characteristics In nature, there are many directly perceptible cell polarity phenomena, for example, when the cut-off body of a worm regenerates, the head regenerates from the section towards the original head, and the tail regenerates from the section towards the original tail Recently, the research team of Professor Dynasty of the school of life sciences of the University of science and technology of China revealed the molecular mechanism of maintaining the polarity of nerve cells, and relevant achievements were published online in the Journal of the National Academy of Sciences The nervous system is the most important functional regulation system in human body As the basic structure and functional unit of nervous system, nerve cells are highly polarized cells Typical nerve cells are composed of dendrites, cell bodies and axons that transmit signals Different substances constitute different shapes and unique physiological functions of dendrites, cell bodies and axons, so as to maintain the polarity of nerve cells In biology, scaffold protein is an important regulatory factor in many key signaling pathways As the most important protein complex organizer in the beginning segment of axon, a neural scaffold protein named "ankyrin-G" is the marker protein of the beginning segment This protein maintains the polarity of axons and dendrites by selectively regulating the proteins and specific organelles entering axons However, the molecular basis of this selective regulation of substances in and out of axons is not clear In this study, the dynasty research group determined the direct interaction between ankyrin-G and the regulatory protein Ndel1 of the important molecular motor complex in cells through biochemical experiments in vitro, and carried out quantitative binding capacity detection By systematically comparing the dissociation constant of the binding between the two proteins, the assembly of the complex was systematically analyzed at the biochemical level Through a series of cell biology research on ankyrin-G / Ndel1 complex in mouse hippocampal neurons, the research group found that ankyrin-G / Ndel1 complex can selectively prevent substances not originally belonging to axons from entering axons at the beginning of axons, so as to maintain the polarity of neurons This research work provides a structural basis for understanding the tissue structure and maintenance of neural polarity at the beginning of axons of nerve cells, and provides a theoretical basis for the study of the pathogenesis of human mental system diseases caused by corresponding gene mutations.