Biological complexity: heart muscle precise design (Introduction)

by David Turell , Wednesday, October 14, 2020, 20:13 (1289 days ago) @ David Turell

The muscle fibers are specifically tailored at the same length for proper contractions:

https://phys.org/news/2020-10-molecular-heart.html

"Filament-like proteins in heart muscle cells have to be exactly the same length so that they can coordinate perfectly to make the heart beat.

"Another protein decides when the filament is the right size and puts a wee little cap on it. But, if that protein makes a mistake and puts the cap on too early, another protein, leiomodin, comes along and knocks the cap out of the way.

"This little dance at the molecular scale might sound insignificant, but it plays a critical role in the development of healthy heart and other muscles. Reporting in the journal, Plos Biology, a WSU research team has proven for the first time how the mechanism works.

***

"Heart muscle is made of tiny thick and thin filaments of proteins. With the help of electrical signals, the rope-like filaments bind and unbind in an intricate and precise architecture, allowing heart muscle to contract and beat.

"The thin filaments are made of actin, the most abundant protein in the human body. Tropomysin, another protein, wraps itself around the actin filaments. Tropomyosin together with two other proteins, tropomodulin and leiomodin, at the end of the actin filaments act as a sort of cap and determine the filament length.

"'It's beautifully designed," said Kostyukova, whose research is focused on understanding protein structures.

"And, tightly regulated.

"To keep heart muscle healthy, the actin filaments, which are about a micron long, all have to be the exact same length. In families with cardiomyopathy, genetic mutations result in formation of filaments that are either too short or too long. Those affected can have significant heart problems that cause disability, illness and death."

Comment: I don't have to comment about the marvels of the design, as the authors have done it.