Boster Pathways-> Cytoskeletal Regulation and Vesicle Trafficking

Regulation of Actin Dynamics Pathway


Microtubules are essential for cell polarity, polarized cell motility, intracellular vesicle trafficking, and chromosomal segregation during mitosis. Microtubules (MTs) are nonequilibrium polymers of /-tubulin heterodimers that undergo GTP hydrolysis on the -tubulin subunit after construction.

What are microtubules?

Actin filaments are formed in the eukaryotic cells and are essential for many of the movements especially those involving the cell surface without action filaments e.g an animal cell could not crawl along a surface , engulf a large particle by phagocytosis or divide into two. Actin is unstable but it can be stable structures in cells e.g the contractile apparatus of muscles.

Actin dymanics pathway can be regulated in various number of ways including the phosphorylation/dephosphorylation of the colifin, through the Rho family GTPases, G-actin binding proteins, the Arp2/3 complex among others.



History of Actin

Actin was first observed experimentally in 1887 by W. D. Halliburton, who extracted a protein from muscle that "coagulated" preparations of myosin and which he dubbed "myosin-ferment" (Halliburton 1887). However, Halliburton was unable to further characterize his findings and the discovery of actin is generally credited instead to Brúnó F. Straub.

RHO FAMILY GTPases

Signals received by cell receptors through chemical messengers like the growth factor, hormones and cytokines are transmitted to Rho family GTPases and more so Rho, Rac, Cdc42. Actomyosin, movement, lamellipodia and filopodia formation develops due to the dispatchment of the intergraded signalling pathways to the cytoskeleton effector proteins.

Cell migration, cytokinesis, endocytosis, morphogenesis during development can be impaired due to the ectopic expression of dominant negative mutants of Rho family GTPases in the mammmalian cells.



History of Actin

Actin was first observed experimentally in 1887 by W. D. Halliburton, who extracted a protein from muscle that "coagulated" preparations of myosin and which he dubbed "myosin-ferment" (Halliburton 1887). However, Halliburton was unable to further characterize his findings and the discovery of actin is generally credited instead to Brúnó F. Straub.