The Golgi Apparatus

And now, a Petrarchan sonnet:

In eighteen ninety-seven, Golgi saw
A strangely bundled stack of cisternae.
And though the image be but white and gray,
Italian Golgi’s eyes widened with awe.
Four regions! To what duties are they called?
With naked eye, poor Golgi could not say.
But tests and time shone light upon the way
That molecules pass safely through cell walls.
This organelle be two-faced: cis and trans.
And molecules go from ER to cis.
The destination? Why, that is the key!
Glycosylation, bound for far off lands.
When vesicle and membrane do touch lips,
Tagged molecules towards home sweet home they flee.

While the likes of Petrarch and Millay may have been able to convey an eternity of complexities within fourteen lines of iambic pentameter, I unsurprisingly found the Golgi apparatus difficult to package (no pun intended) into a sonnet. On a basic level, the Golgi does exactly what the above poem details: It accepts proteins from the rough endoplasmic reticulum, subsequently modifying and addressing them for their future homes outside of the cell. Yet the Golgi does far more than your average FedEx. For one, the Golgi performs a few domestic, intracellular jobs, mostly delivering apoptotic proteins and enzymes to lysosomes. But it focuses primarily on international shipping — boxing proteins into exocytotic vesicles for continuous secretion or into secretory vesicles for condition-dependent release. Moreover, the folds of the cisternae also serve as a “finishing school” for molecules, appending carbohydrates and using ATP found in the lumen of the Golgi to attach phosphates.

What makes the Golgi so cool? If cells were nations and proteins were people, then the Golgi apparatus would be some combination of graduate schools and post offices. Without it, molecules are left unfinished and directionless. So until cells evolve email and extension schools, the Golgi appartus will continue to remain central to both intra- and intercullular communication.

Image Credit: http://wikimedia.org (Louisa Howard)