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Dr. Steven Griffiths Monthly Column, published in the Times & Transcript
Cells always on edge of calamity
Tuesday November 18, 2008
The human resources division at McFeely, Nabbit and Dunne has decided that a deep shag carpet might be just the thing to distract clients from outrageous consultancy fees. Further wishing to create cozy ambience, they've also cranked up the thermostat.
Unforeseen "setbacks" ensue.
The carpet builds up such a charge on overheated employees that they begin to stick together like sweaty limpets. While making copies, Angie glomps on to Bob (who is sneaking off to the bathroom again). Angie and Bob haven't been this close since the trip to the maple syrup farm. We are close to disaster and not just in Bob's pants. All over the department, things are going haywire. Nigel from IT -- here for one of those one-click installations beyond mere mortals -- struggles to extricate himself from the intern like Br'er Rabbit in a sticky situation. Criminy: now the whole floor will be running outdated software and Alice won't make it to McBuns. Periodically, with a crackle and a squeal, another discharge of electrons makes its mark. That shifty guy, just back from hunting, makes a dash for the elevator squealing like a little girl. Too late! He is felled by a flash of blue karma. Helpless now, the door repeatedly opens and closes on his head. Still -- fair's fair on that one.
Will HR's esthetic blooper lead to terminal downsizing? No. The boss is a wily veteran and he has seen this sort of thing before. Several years ago (when the company was called Albatross Focus Inc.), "Vinnie's van der Graaf N' Stuff" opened across the street. Since that disastrous day -- since spoken of only in hushed whispers as "the Great Frizzle of Ought-Sizzle" -- he's hired a team of specially trained little people to prevent another disaster. They are called "The Chaperones". Seconds after the Boss presses the button under his Newton's Cradle, here they come: scrambling through the access tunnel resplendent in bright yellow static-free, water-repellant overalls.
Now they get to work, squeezing into nooks and crannies, delivering their special little hugs to neutralize charges on annealing, slippery staff. Soon everyone is up and running about again, bankrupting gullible clients. OK Nigel: you're not fooling anyone. Get off the intern.
The cells of our body are constantly on the edge of such calamity.
Imagine this time that our cells are offices in miniature, with millions of employees called proteins. Each cell exchanges goods and services with other tiny businesses, all manufacturing their own niche product. Raw materials and commuters are transported from cell to cell in shuttles called exosomes. Like Angie and Bob though, the protein employees are also vulnerable to sudden changes in electrical charge and temperature. They also have a similar tendency to cling to one another in a crisis. Rather than ill-advised decor or insensitive management, protein jeopardy consists of heat and electron-overload from diet, ill-health or physical exertion. Just why are proteins so vulnerable?
Proteins are not rigid bricks, but, like us, have to be flexible to do their jobs. Unravel a protein and you might think of a string of beads. Look closer and you will notice that the beads come in 20 different shapes and sizes. Some beads try to hide away from the watery contents of cells because they are rather oily. Other beads have charges on them that either repel or attract others (rather like magnets).
Upon releasing the ends of the string, the beads wind around one another until they are as comfortable with each other and their surroundings as possible. In this state they have reached thermodynamnic equilibrium or, as I like to call it, the "Goldilocks shape" because it's "just right" (Cosmologists: bite me). There is a Goldilocks shape for each of the 2 million different proteins we need to run our cellular business. Skill sets among our employees range from the conversion of food molecules into packets of energy called ATP to the packaging of FedExosomes for dispatch to partners and clients. Under optimum circumstances, protein activities dovetail into one another like relay runners passing the baton, maximizing productivity in their chosen sector.
All too often though, a bit of chaos is thrown in: perhaps a salt imbalance from that triple taco burger, a scorched earth campaign against the 'flu, or maybe a workout at the gym.
With the imbalance, the beads begin to vibrate. The charged and oily beads that normally hide away and hold the protein together begin to poke out like tiny hernias. In the same way that oil droplets merge on a puddle, and rubbed balloons stick to the ceiling, afflicted proteins begin to aggregate. The cell business is going into foreclosure. Who you gonna call?
Surprise! Our saviours in this instance are also called chaperones or, more commonly heat shock proteins (HSPs). Dalton for Dalton, the HSPs may be the single most important family of molecules that prevent us from becoming a bag of jellyfish.
Wait: it gets cooler. The most active HSPs (HSP70) are shaped like piranhas. The jaws of HSP70 are lined with teeth that are actually arrangements of beads that can neutralize or match the charged and oily pokies.
Meanwhile, in the tail of HSP70, there is a slot that takes and breaks one of those ATP energy packets, rather like a loonie being changed for quarters. This payment causes the jaws of an HSP70 piranha to open and shut.
By repeatedly accepting loonies of ATP to make change, swarms of HSP70 piranhas go through the process of chomp and release, preventing their colleagues from sticking together. The triage of HSP70 nibbling allows the beads to gently shuffle back into Goldilocks mode.
Like Angie and Bob in our office adventure-romance above, the protein staff is soon up and running about again, making sure that cellular business is booming. Bless you, HSPs!
But sometimes, HSPs are recruited for devious purposes. How do our valiant search and rescue heroes get drawn to the Dark Side? In our Christmas edition we'll learn how our munchy angels get their wings dirty.
Stay Frosty.
Article as published:
http://timestranscript.canadaeast.com/news/article/484437
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