WTF Life? (Episode 1): The Amazing Cellular Superhighways and Tireless Motor Protein "Trains."

[KuriousKatKommittee]

Today, class, we is gonna talk (Ctrl C & V from Wikipedia) about autist niggas' favorite topic: Trains. But not the Amtrak cargo trains passenger trains, their serial numbers and so on to arouse your average low-functioning autist but the trains that all living things have inside our bodies RIGHT NOW.

"Say wuhhh?"
That's rite. Our lives, our existence in this plain plane of existence, depend on an intricate network of intra- and inter- cellular "freight trains" making their daily deliveries (UK niggas free to picture "Tesco vans" bringing you the "Pork Faggots" and other fruity groceries) every day, every second, and as JohnSmith is gonna soon find out, his are heading towards a serious derailment but more about severe neurodegenerative conditions later.

Quick rundown for niggas too cool for biology: Your brains, skin, hearts, and feminine penises are made of many tiny microscopic things called cells. These cells are like countries, with their own microscopic industrial, agricultural, law-enforcing, and freight transport sectors and today we examine the last one. Come join train conductor Triple K's wonderful autistic trip inside your cells (What's next? Trip inside your boypunanis? Smh.).

Content

1. Laying the Tracks
2. Gotta Go Fast
3. The Day All Trains Stopped

1. Laying the Tracks

Now, running with the train metaphor, there are two notable railroad engine models which I am going to dub Dagny Taggart MK I (dynein) and Dagny Taggart MK II (kinesin). The railroad tracks are called "microtubules."

Here is how microtubules look like (nuclei in blue, microtubules in green).

Fg. 1. Dagny Taggart MK I (dynein) on a track shipping valuable cargo, some valuable dope that keeps you alive.


Fg. 2. Dagny Taggart MK II (kinesin).

(Note: The speed of the movement in these two visualizations does not represent actual "in vivo" speed.)

2. Gotta Go Fast

Here is where the train metaphor comes in, instead of likening the activity to a spooky ant colony. But, first, technical specifications; speed of the models, etc:

1. Dynein

• Speed: Operating at average in vivo speeds of approximately 2 µm/sec, fast retrograde transport can cover 10-20 centimeters per day.
• Fuel type: Adenosine triphosphate.
• Description: [D]yneins, move towards the minus end of the microtubule. Thus, they transport cargo from the periphery of the cell towards the center. An example of this would be transport occurring from the terminal boutons of a neuronal axon to the cell body (soma). This is known as retrograde transport.

2. Kinesin

• Speed: There are two classes of slow anterograde transport: slow component a (SCa) that carries mainly microtubules and neurofilaments at 0.1-1 millimeters per day, and slow component b (SCb) that carries over 200 diverse proteins and actin at a rate of up to 6 millimeters per day. The slow component b, which also carries actin, are transported at a rate of 2-3 millimeters per day in retinal cell axons.
• Fuel type: Adenosine triphosphate (ATP)

• Special features:

- Viruses (herpes simplex virus, rabies virus, polio, common cold viruses) have the genetic ability to both hijack the train and switch the direction of the train.
- Kinesin has the novel ability to switch directionality.

(Note: X-ray images.)

3. The Day The Trains Stopped

Now JohnSmith and you JohnSmiths of the world lissen up, selekta called Life is picking some wicked junglist tune for you. Sick.

As in neurologically sick. Neurodegenerative processes "are linked to genetic mutations in the motor proteins, kinesin and dynein."

In this case we is talking train wreckage of magnificent biblical babylonian proportions. Cargos spilled everywhere,* trains running late, toilets not working, you name it.

E.g. Alzheimer's (and, interestingly, the process of aging itself) works this way:

- A cargo-receptor for anterograde transport motors, the kinesins, , has been identified as the amyloid precursor protein (APP), the parent protein that produces the senile plaques found in Alzheimer's disease.
- Transport from hippocampus to forebrain is decreased in aging and destination is altered by the presence of Alzheimer's disease plaques.

Translated from nerdspeak: No more trains because train stations are no more. Gone. Finished. (True, I am motherfucking exaggerating here but let me put it this way: Train schedule changes from efficient, always on time to inefficient, like waiting for a train in Japan versus waiting for a train in Uganda.)

Hope that did not derail your emotional trains. Yet.