Cell Biology

                         

                                                               Kinesin

A kinesin is a protein belonging to a class of motor proteins found in eukaryotes cells.

Kinesins move along microtubule (MT) filaments, and are powered by the hydrolysis of ATP, thus kinesins are ATPases. The active movement of kinesins supports several cellular functions including mitoses, meiosis and transport of cellular cargo, such as in axonal transport. Most kinesins walk towards the plus end of a microtubule, which, in most cells, entails transporting cargo from the centre of the cell towards the periphery. This form of transport is known as anterograde transport. In contrast, dyneins are motor proteins that move toward the microtubules' minus end.

                                                    Dynein

Dynein is a motor protein in cells which converts the chemical energy contained in ATP into the mechanical energy of movement. Dynein transports various cellular cargo by "walking" along cytoskeletal microtubules towards the minus-end of the microtubule, which is usually oriented towards the cell center. Thus, they are called "minus-end directed motors." This form of transport is known as retrograde transport. In contrast, kinesins, which are motor proteins that move toward the microtubules' plus end, are called plus-end directed motors.

                                                      








                                                                      Profilin

Profilin is an actin binding protein involved in the dynamic turnover and restructuring of the actin cytoskeleton. It is found in most of eukaryotes cells. Profilin is important for spatially and temporally controlled growth of actin microfilaments, which is an essential process in cellular locomotion and cell shape changes. This restructuring of the actin cytoskeleton is essential for processes such as organ development, wound healing, and the hunting down of infectious intruders by cells of the immune system.  

Profilin binds some variants of membrane phospholipids. The function of this interaction is the sequestration of profilin in an "inactive" form, from where it can be released by action of the enzyme phospholipase C.

Profilin is the major allergen present in birch, grass, and other pollen.