Understanding how aged¹ and damaged mother cells manage to form new and undamaged daughter cells is one of the toughest riddles谜语 of ageing, but scientists now know how yeast³ cells酵母细胞 do it. In a groundbreaking开创性的 study researchers from the University of Gothenburg, Sweden, show how the daughter cell uses a mechanical "conveyor belt传送带" to dump damaged proteins in the mother cell. "This ensures that the daughter cell is born without age-related damage," says professor Thomas Nyström from the Department of Cell and Molecular⁴ Biology.

Thomas Nyström is a professor of microbiology at the University of Gothenburg and one of Sweden's leading researchers in the field of cellular⁵ and molecular biology分子生物学. His research group has published countless⁶ scientific discoveries about cell ageing which have provided a new understanding of aging and age-related diseases. Now he and his colleagues have identified a key piece in the ageing puzzle.

Mechanic transport

In a study published as a feature article in the scientific journal Cell, two collaborating⁷ research groups at the Department of Cell and Molecular Biology have been able to show how newly formed yeast cells transport damaged and aged proteins back to the mother cell, guaranteeing that the new cell is born young and healthy.

Mother dustbin

"Previously⁸ it was believed that these structures allowed only one-way traffic of proteins and organelles细胞器 from mother cell to daughter cell," says Nyström. "We can now show that damaged proteins are transported in the opposite direction. In principle, this means that the daughter cell uses the mother cell as a dustbin垃圾箱 for all the rubbish resulting from the ageing process, ensuring that the newly formed cell is born without age-related damage."

Conveyor belt

In the study, the researchers show that this transportation is mechanical, using conveyor-like structures called actin肌动蛋白 cables. A special gene⁹ which controls the rate of ageing, called SIR2, is needed for these cables to form properly. Previous research has shown that changing the SIR2 gene can markedly extend the life-span of an organism.

Longer life

"Increased SIR2 activity means a longer life, whereas a damaged SIR2 gene accelerates ageing," says Nyström. "This has been demonstrated in studies of yeast, worms, flies and fish, and may also be the case in mammals哺乳动物."

Future treatment

This knowledge of how age-damaged proteins are transported from daughter cell to mother cell could eventually be used in the treatment of age-related diseases caused by protein toxicity¹⁰毒性 in humans, but Nyström says that it is too early to say how.

The first step

"The first step is to study whether this transportation of damaged proteins also occurs in the cells of mammals, including humans, for example in the formation of sex sells and stem cells."