If I learnt anything from watching the 2004 film “Mean Girls”, it is that where you sit in the cafeteria is crucial. Okay, whilst not entirely true, the film explains how at high school, everyone fits into different cliques and these dictate the group of people you sit with at lunch; you have your Freshman, Desperate Wannabes, The Greatest People You Will Ever Meet and, of course, The Plastics. When re-watching this Teen/Comedy classic the other day, it got me thinking, since there are different types of proteins, if I were one, which would I be?
The popular one
Always getting invited to events, receiving messages and interacting with people throughout the day? Some proteins make lots of interactions too. One group of proteins with many interacting partners are the kinases – proteins that add phosphate to other proteins. They are critical in numerous processes from regulating transcription, the cell cycle and division to metabolism. Not only do they interact with the proteins they phosphorylate, but also a host of regulatory proteins, making them very popular proteins indeed.
With the abundance of touch-screen phones and our dependency on them, scrolling through Twitter, Instagram or even Asheekeyscienceblog posts, ‘The scroller’ is a clique that keeps expanding. The repetitive attachment and detachment of a finger from the phone screen, required for scrolling, is very similar to the action of a motor protein, myosin. Myosin plays an important role in muscle contraction. To achieve this, myosin repeatedly binds, detaches and binds further along a filamentous protein called actin, causing the two proteins to overlap and contract the muscle.
The unorganised one
Now everyone has a bit of disorder in their life. The same is true for proteins. Despite the paradigm that proteins fold into a specific and functional 3D structure, more than 40% of proteins contain large intrinsically disordered regions (at least 30 amino acids long), with some proteins containing much more disorder than others. But unorganised does not equal unimportant – these proteins still play a critical role in the cell. For example, p53 is infamous in the protein world and has been termed the ‘guardian of the genome’, yet nearly 50% of the protein is disordered. A bit of disorder then can definitely be beneficial.
The organised one
There are many types of proteins that could describe an organised protein. Why? Because for a cell to function and survive biochemical processes and interactions need to occur at the right place and the right time. So what proteins oversee this organisation? Well, in fact no one group of proteins could take on this momentous task, but one class of proteins that are involved in regulating many processes are the G-proteins. The G-proteins are a large family of proteins that use a switch-like behaviour to transmit cellular signals to coordinate events from cell movement, nuclear transport to cell growth.
The sporty one
Agile? Speedy? Energetic? But are you as fast as carbonic anhydrase? With an operating rate of up to 106 reactions per second, carbonic anhydrase is a speedy enzyme that catalyses the conversion of carbonic acid into carbon dioxide and water. This catalytic rate, which helps control the acid-base balance in the blood, makes carbonic anhydrase one of the fastest enzymes in the cell.
Reads a lot
Whether fiction or non-fiction, an autobiography or a good blog it can be easy to spend a lot of time reading. But what about reading a book made up of only A, T, C and G? This is a polymerase’s favourite! RNA and DNA polymerases spend their day reading these four letters that compose the sequence of DNA in a cell. Whether catalysing transcription or synthesising new DNA strands, these polymerases are the masters of reading.
So, which protein clique are you?