Scientists from the University of Basel have discovered tiny “folding factories” in cells. Without them, proteins like insulin cannot form properly.
Proteins assume many tasks in cells, from the transport of substances to digestion. So that they can assume their functions, they must be properly folded, the University of Basel said on Monday.
To fold the proteins, there are auxiliary proteins in the body, called hits. Until now, scientists have thought that these folding auxiliaries have floated individually in the endoplasmic reticulum, a cellular sub-compartment where the proteins are folded.
Folding machines
However, the authors of this new study discovered that the chaperons are organized independently and form structures in the shape of droplets, called condensates. According to the university, these condensates constitute a kind of treadmill on which protein folding machines are arranged optimally.
This discovery, published in the journal Nature Cell Biology On Monday, constitutes “a real turning point”, according to the manager of the Sebastian Hiller study, quoted in the press release.
Diabetes and mutations
The study is part of an observation: in several genetic diseases, including diabetes, mutations have been found in a chaperon protein called PDIA6. “So we started studying its function in the cell,” said Sebastian Hiller.
As the authors were able to show it, PDIA6 makes several different chaperons unite. In cells with PDIA6 mutations, these condensates are not formed.
In another experience, scientists have shown that cells without these mini-users produce less insulin. This is consistent with the observations that patients with PDIA6 mutations suffer in particular from diabetes.
Lia with ATS