Friday, August 6, 2021

Creation Moment 8/7/2021 - Kinetochore: Your Genetic "traffic cop"

I will praise thee; for I am fearfully and wonderfully made
Psalm 139:14
 
"Musacchio waxes eloquent, as if he has been watching a grand opera in a foreign language. He thinks he can now can understand all the words and see the overall plot, but still is trying to figure out the story details.

As a human cell begins division, its 23 chromosomes

duplicate into identical copies that remain joined at a region called the centromere. Here lies the kinetochore, a complicated assembly of proteins that binds to thread-like structures, the microtubules. As mitosis progresses, the kinetochore gives green light to the microtubules to tear the DNA copies apart, towards the new forming cells.The kinetochore is a beautiful, flawless machine: You almost never lose a chromosome in a normal cell!”, says Musacchio. “We already know the proteins that constitute it, yet important questions about how the kinetochore works are still open: How does it rebuild itself during chromosome replication? How does it bind to the microtubules? And how does it control them?”

Beautiful. Flawless. The kinetochore (from the Greek “motion place”) binds the spindle fibers to the centromere of each chromosome, a spot at the center of a chromosome made for attachment to the spindle. Those who recall the stages of cell division in high school remember that the chromosome pairs all line up in the center of the cell. At metaphase, something “lassos” each sister chromatid (individual member of the pair) at the centromere and exerts force to pull them apart into the daughter cells at anaphase.

---The kinetochore is right at the center of this action, binding to both the centromere and the microtubules in the spindle. 
It is therefore not only a machine able to contact each chromosome’s centromere; it is also a traffic cop. It will not let cell division proceed until it gives the green light.

 What the Max Planck team actually saw was not a random,

purposeless process on stage. They saw a beautiful, flawless machine that works perfectly almost all the time.  

Kinetochores are pulling chromosomes apart into daughter cells every day, in every eukaryotic organism, all over the world." CEH