Solved by a verified expert:Assignment 2Deadline: 27th Sep 2016Slot: G1Course: Cell and Molecular Biology Code: BST5003Analyze the Data: Actin AssemblyUnderstanding of actin filaments has been greatly facilitated by the ability of scientists topurify actin and actin-binding proteins and the ability to assemble actin filaments in vitro.Following are various experimental approaches designed to characterize actin assemblyand the effects of actin-binding proteins on actin assembly.a.The graph in part (a) of the figure depicts the actin polymerization rate at the plus(+) and minus () ends of rabbit actin as a function of actin concentration. Assume thatyou could add actin filaments of a predefined length to rabbit actin maintained at theconcentrations labeled A, B, and C in the figure. Diagram the appearance of the filamentsafter a 10-minute incubation at each of the indicated actin concentrations, if the originalfilaments are depicted as follows:Originalfilament : __________________Make sure to mark the location of the original (+) and () ends of the filament on yourdiagrams.(a)b.A novel actin-binding protein (X) is overexpressed in certain highly malignantcancers. You wish to determine if protein X caps actin filaments at the (+) or () end.You incubate an excess of protein X with various concentrations of G-actin underconditions that induce polymerization. Control samples are incubated in the absence ofprotein X. The results are shown in part (b) of the figure. How can you conclude fromthese data that protein X binds to the (+) end of actin filaments? Design an experiment,using myosin S1 fragments and electron microscopy, to corroborate the conclusion thatprotein X binds to the (+) end. What results would you expect if this conclusion iscorrect?(b)c.An in vitro system was developed to study actin assembly and disassembly innonmuscle cells. In this study, tissue culture cells were incubated for several hours with[35S]methionine so that all the actin monomers in each filament were labeled. Actinfilaments were then collected by differential centrifugation and put into a buffercontaining one of three different cytosolic extracts (A, B, or C). The amounts of solubleactin in each sample were monitored over time (see part (c) of the figure). What do thesedata indicate about the effects of A, B, and C on the assembly and disassembly of actinfilaments?(c)