Maximum actin polymerization rate

Range ~2,000 subunits/sec
Organism Fission yeast Schizosaccharomyces pombe
Reference Berro J, Sirotkin V, Pollard TD. Mathematical modeling of endocytic actin patch kinetics in fission yeast: disassembly requires release of actin filament fragments. Mol Biol Cell. 2010 Aug 15 21(16):2905-15. doi: 10.1091/mbc.E10-06-0494. p.2910 left column bottom paragraphPubMed ID20587776
Method "A simple calculation, the difference between the experimental measurements of the numbers of Arp2/3 complex (ARPC5) and capping protein (Acp2p) molecules in a patch (Figure 6D in Sirotkin et al., 2010), established that patches could contain up to 140 free barbed ends, but the simulations showed that actual number is much less, because at every point in time, a large fraction of the Arp2/3 complex has not initiated a branch (Figure 3C). In fact, a rough estimate showed that only eight barbed ends are required to account for the maximum polymerization rate of about 2000 subunits per second (i.e., eight ends×22µM actin monomers×12µM^-1×sec^-1)."
Comments 8ends×22µM actin monomers×12µM^-1×sec^-1=2112subunits/sec
Entered by Uri M
ID 111090