Session 5: Motor Proteins

Motor Proteins Paradox: Session Videos

Is it possible that Motor Proteins are a result of Darwinian Evolution or even Extended Modern Synthesis?

Can you imagine a large city without any transportation system, roads, or traffic?

Eukaryotic cells are like huge cities that demand the presence of such a system! Motor proteins are magnificent nano-robots that move materials, products, and even organelles around in the cell, from target to destination, using a dynamic system of “railroads”, and powered by the same ATP hydrolysis chemical energy cycle of the cell to produce walking-like motion.

You have to see those motors to appreciate how much they resemble robots and how elegant and graphic their motility and interaction with cargo in the cell is unmistakably intricately designed for the purposes of the cell. Kinesin and Dynein motors move along Microtubules, a special linear structure that assembles and disassembles to produce railroads or tracks for the motors to move along!

The motors come in families with hundreds of variants each, and even come with adaptors that make the various types specifically suited or specialized according to cargo type!

Eukaryotic cells cannot survive without the function of motor proteins like kinesin and dynein, but the motors are not present in Prokaryotes which have a much smaller size and no compartmentalization like the eukaryotic cells. The latter would even depend on Microtubules and Motors during its own very critical job of splitting up of chromatin during cell division, hence reproduction, and its very survival.

This poses a set of challenges to the Theory of Evolution that can be quite paradoxical too, some of which are:

1. Specificity and intricacy of the integrated design of the motors themselves and with other components of the system including the Microtubules, ATP catalysis, and the cargo itself, makes it astronomically unlikely that those systems can evolve or co-evolve using Darwinian mechanisms based on “random” mutation and natural selection.

2. The absence of motors in prokaryotes defies the hypothesis than eukaryotes have evolve from them.

3. The chicken or egg paradox between the existence of the system in eukaryotes and the very existence of eukaryotes that cannot exist without their motors and tubules setup, even for the very basic function of cell division, set aside the essential cargo distribution role!

Read more, with references about the topic on article 5 of the evolution course, for more: Article 5

Interview with Dr. James Tour about the topic:

Watch this interview that I do about the topic of Motor proteins with one of the top synthetic chemists in the world, Dr. James Tour.
Make sure to reach Article 5 after of before this video:

This is part 5 of the interview with Dr James Tour, where we talk about the magnificent molecular machines that roam our cells, like Kinesins and Dynein. Dr. Tour is renowned for his work on nanocars which are molecular machines themselves, where he has received distinguished recognition and awards. I ask the question whether such molecular sophisticated systems can arise through evolution through a series of point mutations to the extent that they just happen to occur in Eukaryotes! Join the discussion and share your opinion.

For the full interview, check it out here:

Dr. James Tour, On Abiogenesis and Evolution | Interview and Q&A with @DrJamesTour #JamesTour