Protein of immortality

The "immortality protein" of stem cells has been found

Kirill Stasevich, "Kompyulenta"

Researchers from the University of Michigan (USA) have discovered a protein responsible for the immortality and "eternal youth" of stem cells. Stem cells, as is known, can transform into other types of cells, or they can remain undifferentiated, multiplying, but at the same time retaining the property of "omnipotence". 

Obviously, in this case we are talking about choosing one or another genetic program. And the most common way to switch genetic programs is epigenetic manipulations (modifications of histones, DNA, etc.). Histones are used for packing DNA, and those parts of it that turned out to be tightly packed will be inaccessible to enzymes synthesizing mRNA, that is, these genes will be silent. If the DNA is free of histones, then its genes will be open to work with them.

Histones, in turn, can behave differently, depending on what modifications they carry. If acetyl groups are attached to histones, they are not able to interact tightly with each other, and therefore DNA will be open to transcription factors. Accordingly, histone acetyltransferase enzymes, which supply histones with acetyl groups, work as DNA activators.

If a cell does not want to differentiate, but wants to remain in the stem entity, it needs to maintain the activity of a certain set of genes responsible for such a state of immortality. As the researchers write in the journal Cell Stem Cell (Li et al., The Histone Acetyltransferase MOF Is a Key Regulator of the Embryonic Stem Cell Core Transcriptional Network), the only enzyme that performs this work in stem cells was the Mof protein. It is worth emphasizing that scientists have worked with pluripotent embryonic stem cells, which can turn into any cell of the body at all. That is, histone acetyltransferase Mof is responsible for the most general non-specialization of stem cells, for, so to speak, their original immortality.

Two human embryonic stem cells after division (photo by David Scharf).

Most of the studies are devoted to the implementation of a particular specialization program. That is, scientists usually find out which epigenetic control proteins are responsible for activating the genes of the epithelial, or nervous, or some other pathway of development. In this case, the reverse work was done, the authors suggested that the immortality of stem cells, as well as their differentiation, is subject to a certain program. The gene encoding Mof is unusually conservative, its sequence is the same in such different organisms as mice and drosophila, so it can be assumed with a high degree of confidence that in humans it looks and works the same as in other animals. Perhaps the management of this gene will help in the future to create and maintain lines of induced pluripotent stem cells, with which so many hopes of regenerative medicine are associated.

Prepared based on the materials of the University of Michigan:
Stem cells can become anything -- but not without this protein, U-M scientists find.

Portal "Eternal youth" http://vechnayamolodost.ru22.08.2012