Blogging Challenge Inverted (2)

Here is the second of two guest blogs from my tutorial students, completing my inverted blogging challenge. This one is from Louie Barnett, who provides an entertainingly seasonal take on the murky world of G-protein coupled receptors. Take it away, Louie:

All I want for Christmas is… a GPCR?
Louie Barnett

It’s coming to that time of year when people are thinking about what they want for Christmas. Some will want a ring, some chocolates, some even may want socks, but I argue that some would want fully functioning GPCRs!

‘Don’t be stupid’, I hear you cry. Well, just think about it. I’m talking about an important part of our make up here. Indeed, there are more than 800 GPCRs identified, making it the largest superfamily in the human genome! And if you’re still not convinced, over 3% of the genome codes for them! So, they must be important, mustn’t they? (That’s a rhetorical question, of course they are!)

For those of you who shouted, ‘what are they?’ instead of ‘Don’t be stupid’, GPCRs (or G-protein coupled receptors) are designed to activate G proteins by changing conformation, this then allowing interaction with the G protein, thereby causing an intracellular response to an external stimulus, allowing complex responses. This can be any stimulus, including odours, such as that Christmas turkey or that mince pie with a glass of sherry if you’re lucky enough to be Santa Claus. But smell isn’t the whole story. They’re further involved in neurotransmission, cellular metabolism, secretion, cell growth, immune defence and differentiation amongst other things. Core blimey, GPCRs have their fingers in all sorts of pies.

Now the main question on your lips must be, ‘why would I want that for Christmas?’ Well, you personally might not need them, but others, with ones that aren’t fully functioning, will. GPCRs are linked to a great plethora of diseases (many of them very serious), and consequently are the most actively targeted class of polypeptides for small molecule drug design. However, we unfortunately know very little about them, with many boffins working busily to uncover their structures and secrets. It is hoped that new, pioneering techniques will expose some new clues.

The human race is not completely in the dark however. Via electron microscopy reconstruction (the process of generating a 3D model from a 2D image), we are able to accurately estimate the structure of rhodopsin. It is thought (but not known) that many other GPCRs have a similar structure to this, thus giving scientists an insight into the murky GPCR world.

So, next time you write your Christmas list, just think about the amazing things that microscopic proteins are doing within you, and thank God that you don’t need them for Christmas!