DEGRADING PATHOGENS AND DISTRIBUTING FAT : THE MANY FACES OF MOTOR PROTEINS

Molecular Motors are Nanoscale Machines that generate force by burning fuel (ATP), thus causing your heart to beat. You can therefore call these Motors the "Engines of Life". The same motors also transport micron-sized "Cargoes" such as Bacteria, Virus, Mitochondria etc. inside the living cells in your body. A focussed Laser beam can be used to make an Optical tweezer where one can measure the tiny pico-Newton forces generated by a single Motor. Such studies have been at the forefront of Single-molecule interdisciplinary research for decades. Unfortunately, such single-molecule studies cannot be extrapolated to understand the Biological functions of these motors. We have used Optical tweezers to understand how these Motors work in large teams inside living cells. I will discuss how a "Catch-bond", which counter-intuitively strengthens under mechanical stress, may allow these motors to compete against each other when they are carrying a bacteria that has to be killed inside your immune cells. I will then move to an unusual cargo, tiny fat bodies, that are also moved around by motors inside the cells of your Liver. I will discuss how this motion of fat bodies reflects in a blood test, and why the poorly understood physics of the membrane covering the fat body is important.