What Is the Ubiquitin System?

Ubiquitin is a small protein found in all eukaryotes (most eukaryotic cells). Ubiquitin is composed of 76 amino acids and has a molecular weight of approximately 8.451 kDa. Its main function is to label the proteins that need to be broken down so that they are degraded by the 26S proteasome. Some receptors on the regulatory subunits of the 26S proteasome can recognize K48 and K11-linked polyubiquitinated proteins, and the 20S core subunit hydrolyzes substrates under ATPase energy. Ubiquitin can also label transmembrane proteins and participate in the bubble transport of proteins. Atypical ubiquitin chains play an important role in cell signaling, endocytosis, and DNA damage repair, regulating the NF-B pathway. It is highly retained in eukaryotes, with 96% similarity between human and yeast ubiquitin.

Ubiquitin

Basic Information

Ubiquitin (ubiquitin) is a type of small molecular protein widely existing in eukaryotic cells, with a size of 76 amino acid residues. Ubiquitin can be linked to each other through an enzymatic reaction to mediate the degradation of target proteins.

chemical reaction

The catalysis of a series of reactions takes place. The whole process is called

Nobel Prize in Chemistry

Hershko, Ciechanover, and Varshavsky won the Albert Lasker Prize for Basic Medicine in 2000. This award is known as half of its winners will receive the Nobel Prize, and from this time on, ubiquitin began to be considered as a candidate for the Nobel Prize. In the second year, 2001, the 34th Nobel Institute held the title of "Regulation of cellular function by the ubiquitin-proteasomesystem" at the Karolinska Institute in Stockholm. This meeting included Hershko, Ciechanover, Varshavsky, Goldberg, etc. Humans have also convened experts on cell cycle, immunity, and neurology. Then, as everyone knows, in 2004, Hershko, Ciechanover, Rose and others won the Nobel Prize in Chemistry.

For the Nobel Prize, both the parties and researchers in related fields are welcome and surprised. Because "there is no Varshavsky but Rose", "not a medical physiology award but a chemistry award".

Related effects

Rose is the authority on the use of ATP for enzymatic reactions. In the early days, Rose and Hershko and Ciechanover conducted joint research. He has made great contributions to the investigation of the mechanism of ubiquitin modification reactions. Since then, he has made extraordinary achievements in the cultivation of talents. In the initial use of biochemical methods to advocate the ubiquitin hypothesis, these three scholars have great achievements.

In my personal opinion, Varshavsky's failure to win the Nobel Prize is indeed very regrettable. Without Varshavsky's outstanding work, the research on ubiquitin would be difficult to extend to the present. Moreover, Varshavsky has published dozens of papers on ubiquitin systems in Nature, Cell, Science and other journals. In contrast, the three winners were almost zero. Probably the significance of this is that the rapid development of modern technologies such as modern genetic engineering, molecular biology, etc., should itself bring about a significant improvement in human gene analysis, and this time the three biochemicals used by these three people The discovery of this new concept with the so-called low-tech basic knowledge of enzymes is of great significance. Therefore, the Nobel Prize is awarded in recognition of the original discovery of this original discovery. The Nobel Committee flaunted itself in recognition of this "initial discovery." Modern highly developed life sciences have produced a large number of papers, and this time the Nobel Prize in Chemistry can be said to be a special warning for this truly original discovery.

There is another thing that made this anecdote published in Nature after winning this award. The day after Hershko announced the Nobel Prize in Medicine and Physiology, he planned to go swimming with his granddaughter, but got the news that he was awarded the Nobel Prize in Chemistry from a phone call from a cousin (the Nobel Committee uses telegrams) Recipients were notified, and before that, a text message was broadcast and the cousin who heard the news notified me). That is, it was extremely unexpected to get a chemistry award. Yes, in recent years, the research on ubiquitin has been expanding in the fields of medicine, pathophysiology and other fields. Many people think that the medical physiology award should be awarded, but it is actually the chemistry award. For this chemistry prize, it is necessary to focus on the discovery of the unique regulatory mechanism of proteins as ligands and their biological significance in order to understand them correctly. Hershko's wisdom, Ciechanover's superior technology and mobility, Rose's profound enzymatic literacy, the result of the joint efforts of these three scientists with different personalities and abilities, established the hypothesis of ubiquitin as a signal for protein breakdown. From the contribution of these three people to the establishment of basic concepts, I think I can understand the significance of the Nobel Prize in Chemistry.