Human body is composed of great number of cells which is one of the most basic parts of living creatures. A cell is the smallest unit of organism, having their own skeleton. This system termed as the cytoskeleton, works in a way that makes it similar to both the skeletons and muscles of human bodies. It maintains the shape of the cell and allows the cell move (NASA, 2004).
The cytoskeleton is a network of fibers throughout the cytoplasm of cell which maintains cell shape, cell locomotion, movement of various elements in the cytoplasm, integration of the most important cytoplasmic organelles, cell division, chromosome organization and movement, and the adhesion of a cell to a surface or to other cells. The cytoskeleton is involved in cellular motility and in moving vesicles within a cell. It helps in the formation of food vacuoles as well. In the absence of cytoskeleton, the internal movement of cell organelles, as well as cell locomotion and muscle fiber contraction could not take place.
The cytoskeleton is an organized group of three prime protein filaments which are microtubules, actin filaments, and intermediate fibers. These structural proteins are made up of three main types: The actin filament plays an essential role in cell progress when related with another contractile protein such as myosin to form actinomyosin. The functions of Intermediate filaments are to retain the cell shape and giving a certain amount potency and stiffness to it. These proteins lengthen across the cytoplasm giving cells mechanical strength and, as in epithelial cells, span from once cell-cell junction to another.
Microtubules form long straight hollow tubes which naturally come up out of a structure at the center of the cell, generally near the nucleus, called the centrosome. It is responsible for a range of functions including transport of organelles and products around the cell, movement of chromosomes during cell division and forms the components of cilia and flagella. The polarity is also significant in terms of the direction of transport along the microtubules as dissimilar motor proteins are accountable for the directional movement.
All the cytoskeleton proteins have several common characteristics, they are a helical array of proteins and they go through fast cycles of polymerization and disassembly so that their cellular skeletal structure is very fluid and rapidly changing (Gary Reiness, 2000). Cytoskeleton is contained in all eukaryotic cells. Current research has discovered that it can be present in prokaryotic cells too. It is a dynamic structure plays important roles in both intra-cellular transport (the movement of vesicles and organelles) and cellular division.
Integrity of the cytoskeleton is indispensable for cell endurance and function, and probable functional consequences of cytoskeletal loss include cell death. Cysteine proteases such as calpain are highly involved in the crash of cytoskeletal proteins (Kampfl et al 1996, Posmantur, et al. 1998). Loss of cytoskeletal proteins such as spectrin and tau is a vital feature in a diversity of acute central nervous system injuries including ischemia, spinal cord injury, and traumatic brain injury (Wang, 2000).
The literature contains widespread information on the proteolytic degradation of two significant cytoskeletal proteins, aII-spectrin and tau, after traumatic brain injury in the fully developed brain. In the mature brain, calpain and caspase-3 create signature 145 kDa and 120 kDa BDP of aII-spectrin (SBDPs) respectively (Pike et al, 2000). Discovery of the bacterial cytoskeleton is quite recent. FtsZ was recognized as the first protein of the prokaryotic cytoskeleton. In 1991, Erfei Bi and Joseph Lutkenhaus discovered that FtsZ assembled into the Z-ring.
The cytoskeleton was formerly considered to be a characteristic only of eukaryotic cells, but homologues to all the major proteins of the eukaryotic cytoskeleton have newly been found in prokaryotes. Cytoskeleton research is a wide area of research that’s why it is not reserved to specialists in medical field, but other scientists are also interested to study about it. Advancement in cytoskeleton research in the European area can only be achieved through a multidisciplinary approach. The manner the cytoskeleton can withstand all of this compressing and stretching while still being strong is the major concern of NASA.
Research is still continued about effect of variable gravity on cytoskeletons. Researchers discovered a way to make the cytoskeleton stiffen and relax. They were able to make cells change into different shapes, too. They erudited that certain shapes make cells succeed. They also learned that other shapes make the cells more about to die. They consider that changes in the cytoskeleton are involved in these actions (NASA, 2004). To conclude, the cytoskeleton is the supporting structure for cells connecting the nuclear matrix to the plasma membrane. It plays a crucial role in the compartmentalization of the eukaryotic cell cytoplasm.
The cytoskeleton controls cell and tissue flexibility during biological processes such as development, wound repair or activation of the immune response. It can be assessed that mutations in genes encoding cytoskeleton proteins cause a huge number of diseases including neurological disorders, immune deficiencies, skin disorders, deafness or muscle dysfunction. References 1) Linda A. Amos and W. Gradshaw Amos. 1991. Molecules of the Cytoskeletion. 2) Kampala, A. , et al. 1996. mu-calpain activation and calpain-mediated cytoskeletal proteolysis following traumatic brain injury.
J Neurochem, pg: 1575-83. 3) Wang, K. K. 2000. Calpain and caspase: can you tell the difference? Trends Neurosci, pg: 20-6. 4) Pike, B. R. , et al.. 2000. Stretch injury causes calpain and caspase-3 activation and necrotic and apoptotic cell death in septo-hippocampal cell cultures. J Neurotrauma, pg: 283-98. 5) Gary Reiness, 2000. Cytoskeleton II: Microtubules, http://www. lclark. edu/~reiness/cellbio/lectures/lect20. htm 6) NASA’s Space Operations Mission Directorate, NASAexplores: January 29, 2004, http://www. nasaexplores. com/show2_5_8a. php? id=04-008&gl=58