Genome complexity: miniproteins sudden apearance (Introduction)

by David Turell , Saturday, February 18, 2023, 23:42 (433 days ago) @ David Turell

A strange relationship with older larger proteins:

https://phys.org/news/2023-02-evolution-mini-proteins-human.html

"Every biologist knows that small structures can sometimes have a big impact: Millions of signaling molecules, hormones, and other biomolecules are bustling around in our cells and tissues, playing a leading role in many of the key processes occurring in our bodies. Yet despite this knowledge, biologists and physicians long ignored a particular class of proteins—their assumption being that because the proteins were so small and only found in primates, they were insignificant and functionless.

The discoveries made by Professor Norbert Hübner at the Max Delbrück Center... "We were the first to prove the existence of thousands of new microproteins in human organs," says Hübner.

"In a new paper published in Molecular Cell, the team led by Hübner and van Heesch now describe how they systematically studied these mini-proteins, and what they learned from them. "We were able to show which genome sequences the proteins are encoded in, and when DNA mutations occurred in their evolution," explains Dr. Jorge Ruiz-Orera, ... bioinformatic gene analyses revealed that most human microproteins developed millions of years later in the evolutionary process than the larger proteins currently known to scientists.

"Yet the huge age gap doesn't appear to prevent the proteins from "talking" to each other. "Our lab experiments showed that the young and old proteins can bind to each other—and in doing so possibly influence each other," says lead author Dr. Jana Schulz, a researcher in Hübner's team and at the DZHK. She therefore suspects that contrary to long-held assumptions, the microproteins play a key role in a variety of cellular functions. The young proteins might also be heavily involved in evolutionary development thanks to comparatively rapid "innovations and adaptations."

***

"...the ability to bind does suggest the proteins might influence each other's functioning. Initial cellular experiments conducted at the Max Delbrück Center in collaboration with Professors Michael Gotthardt and Thomas Willnow confirm this assumption. This leads Ruiz-Orera to suspect that the microproteins "could influence cellular processes that are millions of years older than they are, because some old proteins were present in the very earliest life forms."

[/b]"Unlike the known, old proteins that are encoded in our genome, most microproteins emerged more or less "out of nowhere—in other words, out of DNA regions that weren't previously tasked with producing proteins," says Ruiz-Orera. Microproteins therefore didn't take the "conventional" and much easier route of being copied and derived from existing versions. And because these small proteins only emerged during human evolution, they are missing from the cells of most other animals, such as mice, fish and birds. These animals, however, have been found to possess their own collection of young, small proteins. [/b] (my bold)

"During their work, the researchers also discovered the smallest human proteins identified to date. "We found over 200 super-small proteins, all of which are smaller than 16 amino acids," says Dr. Clara Sandmann, the study's third lead author. Amino acids are the sole building blocks of proteins. Sandmann says this raises the question of how small a protein can be—or rather, how big it must be to be able to function. Usually, proteins consist of several hundred amino acids.

"The small proteins that were already known to scientists are known as peptides, and function as hormones or signal molecules. They are formed when they split off from larger precursor proteins. "Our work now shows that peptides of a similar size can develop in a different way," says Sandmann. These smallest-of-the-small proteins can also bind very specifically to larger proteins—but it remains unclear whether they can become hormones or similar: "We don't yet know what most of these microproteins do in our body," says Sandmann."

Comment: now we have a mini-protein gap along with a pyramidal neuron gap and the Cambrian gap. My bold is an amazing piece of discussion in a Darwinist article. Darwin based scientists don't like gaps. God, the designer is easily evoked. Steps in with new advances whenever He desires.