New Research Explains the ABC of the Evolution of Species

Almost four decades of research have led scientists to suggest that the carrier protein family played an important role in the evolution of species.

The study was conducted at Japan’s Institute for Integrated Cell Material Sciences (iCeMS).

Especially a protein called ABCA1; When signals related to cell proliferation, differentiation, and migration entered a cell, it was crucial in the evolution of vertebrates by helping regulation.

This process was necessary for vertebrates to evolve into more complex organisms with complex body structures.

ATP binding cassette proteins (ABC = ATP Binding Cassette) bacteria are very similar across species, including plants and animals.

There are different ABC proteins that have different transport roles, import nutrients into cells, export toxic compounds other than these, and regulate lipid (saturated and unsaturated fat) concentrations within cell membranes.

Biochemist Kazumitsu Ueda and his colleagues have been working on human ABC proteins for 35 years since they first identified the eukaryote ABC protein gene.

“We believe ABC proteins must have played important roles in evolution,” says Ueda. “By transporting lipids, they enabled plants and animals to thrive on land, protecting them from dehydration and pathogen infection.

It is also assumed that by allowing cholesterol to act as an intermembrane signaling molecule, it accelerates vertebrate evolution. “

Organisms that existed early in world history probably consisted of DNA and proteins surrounded by a leaky lipid membrane.

As organisms evolved, their membranes were strengthened to protect them from the external environment. However, this meant that only organisms that developed special ABC transporters that could transport nutrients across the membrane survived.

ABC proteins also played important roles in forming an outer membrane that protects cells from external stresses and removing harmful substances from inside.

Recently, Ueda and her team studied the roles of ABCA1 and gained a deeper insight into how it regulates cholesterol.

Specifically, they found that ABCA1 exports cellular phospholipids and cholesterol out of the cell to produce high-density lipoproteins, popularly called good cholesterol.

They also found that ABCA1 continuously transfers cholesterol from the inward-facing surface to the outward-facing surface of the cell membrane, and a lower density is maintained on the inside.

This process is temporarily suppressed when the cell is exposed to an external stimulus such as growth hormone. The accumulation of cholesterol on the inner surface triggers the uptake of proteins into the membrane (cell membrane) and modulates signal transduction.

Ueda and her team suggest that ABCA1 allows vertebrates to develop complex biological processes and improved bodies.

Ueda says ABCA1 is quite unique and its exclusive functions surprised the team.

“It was thought that the role of cholesterol was mainly focused on physically strengthening the cell membrane and reducing its permeability to ions. Our research shows it plays a more important role in vertebrates by speeding up their evolution. ” says.

Compiled by: Feyza ÇETİNKOL

Kaynak:science daily

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