Nature analytic protein transport by a famous American academician

Each protein in the cell is like a passenger in the urban public transportation system, with a specific destination and function The channels on the cell membrane can help guide these proteins to their destinations Recently, researchers from Harvard University, Boston University School of Medicine (BUSM) and other places have captured the process of protein passing through the membrane when these channels are open The research results are published in nature on October 24   The corresponding authors are Professor Tom A Rapoport from Harvard University and Christopher W akey, Professor of physiology and Biophysics at Boston University School of medicine Among them, Professor Rapoport is a leading scholar in the field of cell and structural biology His academic achievements are highly recognized He was awarded the honors of academician of the American Academy of Arts and Sciences and academician of the National Academy of Sciences He has a high international academic reputation Dr Rapoport specializes in the transport process of proteins between endoplasmic reticulum, as well as the shape and maintenance of endoplasmic reticulum in morphology He has continuously published many important research results in nature, science, cell and other top international journals   Proteins encoded by genes are macromolecules that perform specific functions, and are also implementers of body functions Many proteins, such as hormones and growth factors, are secreted by cells and moved into the blood system These proteins are processed by ribosomes, which can interact with a channel family called Sec61 / SecY (Sec61 / SecY provides a pathway for membrane penetration) In the beginning, these new proteins are inserted into the channels after they are manufactured The channels also help the new proteins to enter the cell membrane They can act as drug receptors and form ion channels for vision and transmission of nerve cell signals   In this study, the researchers used E coli samples to determine the structure of a highly conserved SecY channel Through electron microscopy and computer analysis, the researchers also captured a SecY channel image of a new protein entering the membrane pore So the researchers found that there was a large movement of the channel, which magnified the membrane pore, allowed the new protein to pass through the cell membrane, and finally reached the destination
"It's similar to a train car passing through a tunnel The SecY / Sec61 channel can help the newborn protein pass through the cell membrane and reach the target position in the body This study provides important information for understanding the function of these channels " AKEY said   Professor Rapoport's other research direction is ERAD mechanism, that is, through the lectins or chaperones of endoplasmic reticulum to identify the secondary structure in the misfolded protein   For example, the hydrophobic region exposed by the protein, damaged cysteine residues or immature group modification can be used to identify the misfolded ERAD, and each ubiquitin complex system with specificity can be used Ligase), which is labeled by ubiquitination, uses ATP hydrolase complex (valosine containing protein in mammalian cells; VCP, also known as p97) to pull the protein out of endoplasmic reticulum   P97 uses the heat energy generated by ATP hydrolysis to provide the energy needed in the transport mechanism, and transports ERAD from endoplasmic reticulum to cytoplasm Because the proteasome system is located in the cytoplasm, the misfolded protein must be transported back to the cytoplasm by the endoplasmic reticulum system, and then identified by the proteasome and degraded by the ubiquitinated era.