In the 21st century, internet and mobile phones have revolutionized the way we communicate. We use text messages or e-mails to send our birthday wishes, MSN to chat, and even Facebook in sharing our lives openly. I still remember some of my friends ‘tweet-ing’ (sending a quick message on Twitter) me about Michael Jackson’s death a couple of days ago. We all know that we still could misunderstand each other even with those sophisticated tools. It might seem surprising but tiny molecules inside our cells constantly chit-chat with their own ‘internet’ and ‘mobile phones’ without any information being misinterpreted. Scientists call this communication ‘cell signalling’.
Inside our body, cells talk to each other constantly. They send signals as responses from different stimuli. Without these responses, no one could survive as the body would not function properly. Immune cells, act as generals, command their soldiers to attack invaders by sending ‘text messages’ or signals called cytokines.
How, then, can cells emit and control the signals traffic? Protein kinases are small molecules inside cells that pass on the signals to other molecules. There are more than 500 distinct protein kinases; each of them has its own specific task. No doubt, faulty kinases, which result in muddled signalling, can cause various diseases. By understanding how these kinases control the signals inside our body, we can also try to manipulate the signals, just like adjusting the volume of our telephone. Many different big pharmaceuticals companies are racing to design drugs that target these kinases.
For example, one of the most understood cell signalling mechanism is TLR signalling which senses the bacterial infection. Our body amazingly can sense different types of bacteria using different ‘antennae’. An ‘antenna’ called TLR 4 is specifically sensitive to gram negative while different ‘antenna’ called TLR2 is sensitive to gram positive bacteria. Both TLR2 and TLR4 will activate distinct responses which lead to the elimination of these harmful bacteria.
There are hundreds of cell signalling events taken place in one second in one organ. When we examine cell signalling inside us, it is countless in just a blink of an eye. It’s impressive, isn’t it?
Image from: Gut 2005;54:718-725 doi:10.1136/gut.2004.038679